Sample records for ilc positron source

  1. Prototyping of the ILC Baseline Positron Target

    SciTech Connect (OSTI)

    Gronberg, J; Brooksby, C; Piggott, T; Abbott, R; Javedani, J; Cook, E

    2012-02-29T23:59:59.000Z

    The ILC positron system uses novel helical undulators to create a powerful photon beam from the main electron beam. This beam is passed through a titanium target to convert it into electron-positron pairs. The target is constructed as a 1 m diameter wheel spinning at 2000 RPM to smear the 1 ms ILC pulse train over 10 cm. A pulsed flux concentrating magnet is used to increase the positron capture efficiency. It is cooled to liquid nitrogen temperatures to maximize the flatness of the magnetic field over the 1 ms ILC pulse train. We report on prototyping effort on this system.

  2. ILC cryogenic systems reference design

    SciTech Connect (OSTI)

    Peterson, T.J.; Geynisman, M.; Klebaner, A.; Theilacker, J.; /Fermilab; Parma, V.; Tavian, L.; /CERN

    2008-01-01T23:59:59.000Z

    A Global Design Effort (GDE) began in 2005 to study a TeV scale electron-positron linear accelerator based on superconducting radio-frequency (RF) technology, called the International Linear Collider (ILC). In early 2007, the design effort culminated in a reference design for the ILC, closely based on the earlier TESLA design. The ILC will consist of two 250 GeV linacs, which provide positron-electron collisions for high energy physics research. The particle beams will be accelerated to their final energy in superconducting niobium RF cavities operating at 2 kelvin. At a length of about 12 km each, the main linacs will be the largest cryogenic systems in the ILC. Positron and electron sources, damping rings, and beam delivery systems will also have a large number and variety of other superconducting RF cavities and magnets, which require cooling at liquid helium temperatures. Ten large cryogenic plants with 2 kelvin refrigeration are envisioned to cool the main linacs and the electron and positron sources. Three smaller cryogenic plants will cool the damping rings and beam delivery system components predominately at 4.5 K. This paper describes the cryogenic systems concepts for the ILC.

  3. A Polarized Positron Source for CEBAF

    SciTech Connect (OSTI)

    Dumas, J. [Laboratoire de Physique Subatomique et de Cosmologie, IN2P3/CNRS-Universite Joseph Fourier-INP, 53, rue des Martyrs, 38026 Grenoble Cedex (France); Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Grames, J. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Voutier, E. [Laboratoire de Physique Subatomique et de Cosmologie, IN2P3/CNRS-Universite Joseph Fourier-INP, 53, rue des Martyrs, 38026 Grenoble Cedex (France)

    2009-09-02T23:59:59.000Z

    A compact polarized positron source for Jefferson Lab is discussed. This scheme relies upon a high polarization (85%), high current (1 mA), low-energy (<100 MeV) electron beam to generate polarized positrons in a conversion target via polarized bremsstrahlung and pair creation. GEANT4 is used to simulate source distributions suitable for a CEBAF-like injector with positron polarization approx60% and nano-Ampere intensity. An experiment to test this scheme is outlined.

  4. A polarized positron source for CEBAF

    E-Print Network [OSTI]

    Dumas, J; Voutier, E

    2009-01-01T23:59:59.000Z

    A compact polarized positron source for Jefferson Lab is discussed. This scheme relies upon a high polarization (85%), high current (1 mA), low-energy (CEBAF-like injector with positron polarization ~60% and nano-Ampere intensity. An experiment to test this scheme is outlined.

  5. ILC Reference Design Report Volume 3 - Accelerator

    E-Print Network [OSTI]

    Phinney, Nan; Walker, Nicholas

    2007-01-01T23:59:59.000Z

    The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2 s^-1. The complex includes a polarized electron source, an undulator-based positron source, two 6.7 km circumference damping rings, two-stage bunch compressors, two 11 km long main linacs and a 4.5 km long beam delivery system. This report is Volume III (Accelerator) of the four volume Reference Design Report, which describes the design and cost of the ILC.

  6. Positron source position sensing detector and electronics

    DOE Patents [OSTI]

    Burnham, Charles A. (South Essex, MA); Bradshaw, Jr., John F. (Winthrop, MA); Kaufman, David E. (Brockton, MA); Chesler, David A. (Newton Highlands, MA); Brownell, Gordon L. (Cambridge, MA)

    1985-01-01T23:59:59.000Z

    A positron source, position sensing device, particularly with medical applications, in which positron induced gamma radiation is detected using a ring of stacked, individual scintillation crystals, a plurality of photodetectors, separated from the scintillation crystals by a light guide, and high resolution position interpolation electronics. Preferably the scintillation crystals are several times more numerous than the photodetectors with each crystal being responsible for a single scintillation event from a received gamma ray. The light guide will disperse the light emitted from gamma ray absorption over several photodetectors. Processing electronics for the output of the photodetectors resolves the location of the scintillation event to a fraction of the dimension of each photodetector. Because each positron absorption results in two 180.degree. oppositely traveling gamma rays, the detection of scintillation in pairs permits location of the positron source in a manner useful for diagnostic purposes. The processing electronics simultaneously responds to the outputs of the photodetectors to locate the scintillations to the source crystal. While it is preferable that the scintillation crystal include a plurality of stacked crystal elements, the resolving power of the processing electronics is also applicable to continuous crystal scintillators.

  7. Superconducting magnet needs for the ILC

    SciTech Connect (OSTI)

    Tompkins, J.C.; Kashikhin, Vl.; /Fermilab; Parker, B.; /Brookhaven; Palmer, M.A. /; Clarke, J.A.; /Daresbury

    2007-06-01T23:59:59.000Z

    The ILC Reference Design Report was completed early in February 2007. The Magnet Systems Group was formed to translate magnetic field requirements into magnet designs and cost estimates for the Reference Design. As presently configured, the ILC will have more than 13,000 magnetic elements of which more than 2300 will be based on superconducting technology. This paper will describe the major superconducting magnet needs for the ILC as presently determined by the Area Systems Groups, responsible for beam line design, working with the Magnet Systems Group. The superconducting magnet components include Main Linac quadrupoles, Positron Source undulators, Damping Ring wigglers, a complex array of Final Focus superconducting elements in the Beam Delivery System, and large superconducting solenoids in the e{sup +} and e{sup -} Sources, and the Ring to Main Linac lines.

  8. FEASIBILITY AND CONCEPTUAL DESIGN OF A C.W. POSITRON SOURCE AT CEBAF

    SciTech Connect (OSTI)

    Serkan Golge

    2010-08-31T23:59:59.000Z

    A feasibility study of a CW positron source for the 12 GeV upgrade at Jefferson Lab (JLAB) is provided. The proposed ? 100 nA Continuous Wave (CW) positron source at JLAB has several unique and challenging characteristics: high current incident electron beam at 126 MeV with a high beam power (up to a MW); CW e? beam and CW e+ production. The multiple scattering is a dominant process when creating e+ in a target, which results a large phase space area of the emitted positrons. An admittance study was done at CEBAF to find the maximum phase space area, which is tolerated in the machine. The measured geometrical transverse admittance (A) were Ax =10 and Ay = 5 mm?mrad at the injector. Energy spread measurement was also done at the ARC1. The fractional spread limit in the ARC1 was measured as ? = 3×10?3 at 653 MeV. By using the optimized results and the CEBAF parameters, three positron injector configurations are proposed; Combined Function Magnet, Two-Dipole and Microtron Dipole configurations. With the assumptions made, by using 126 MeV 10 mA e? beam impinging on a 2 mm W target with a 100 ?m spot size, we can get up to 3 ?A useful e+ current at the North Linac connection. One of the biggest challenges is the target design, which the deposited power is about 60 kW. ILC designs project power deposition up to 13 kW, which would allow the creation of a e+ beam of up to 650 nA otherwise. The results of analytic and monte carlo simulations of the positron production, capture and acceleration are presented. For the target design, a review is presented of solutions for the high power production target. Portions of this dissertation work have been published in two conference proceedings.

  9. POLARIZED POSITRON SOURCE WITH A COMPTON MULTIPLE INTERACTION POINT LINE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    projects. This is essentially due to the high luminosity required, orders of magnitude higher than exist. Eventually, the challenge of the Compton based Positron Source (CPS) is that, despite the low value. POSITRON PRODUCTION WITH COMPTON SCATTERING !"##" $"%& '()*+,-.)/ There are three types of the CPS

  10. Study of an hybrid positron source using channeling for CLIC

    E-Print Network [OSTI]

    Dadoun, O; Chehab, R; Poirier, F; Rinolfi, L; Strakhovenko, V; Variola, A; Vivoli, A

    2009-01-01T23:59:59.000Z

    The CLIC study considers the hybrid source using channeling as the baseline for positron production. The hybrid source uses a few GeV electron beam impinging on a crystal tungsten radiator. With the tungsten crystal oriented on its axis it results an intense, relatively low energy photon beam due mainly to channeling radiation. Those photons are then impinging on an amorphous tungsten target producing positrons by e+e? pair creation. In this note the optimization of the positron yield and the peak energy deposition density in the amorphous target are studied according to the distance between the crystal and the amorphous targets, the primary electron energy and the amorphous target thickness.

  11. Development of a Positron Source for JLab at the IAC

    SciTech Connect (OSTI)

    Forest, Tony

    2013-10-12T23:59:59.000Z

    We report on the research performed towards the development of a positron sour for Jefferson Lab?s (JLab) Continuous Electron Beam Accelerator Facility (CEBAF) in Newport News, VA. The first year of work was used to benchmark the predictions of our current simulation with positron production efficiency measurements at the IAC. The second year used the benchmarked simulation to design a beam line configuration which optimized positron production efficiency while minimizing radioactive waste as well as design and construct a positron converter target. The final year quantified the performance of the positron source. This joint research and development project brought together the experiences of both electron accelerator facilities. Our intention is to use the project as a spring board towards developing a program of accelerator based research and education which will train students to meet the needs of both facilities as well as provide a pool of trained scientists.

  12. SUPERCONDUCTING MAGNET NEEDS FOR THE ILC.

    SciTech Connect (OSTI)

    PARKER,B.; TOMPKINS, J.C.; KASHIKHIN, VI.; PALMER, M.A.; CLARKE, J.A.

    2007-06-25T23:59:59.000Z

    The ILC Reference Design Report was completed early in February 2007. The Magnet Systems Group was formed to translate magnetic field requirements into magnet designs and cost estimates for the Reference Design. As presently configured, the lLC will have more than 13,000 magnetic elements of which more than 2300 will be based on superconducting technology. This paper will describe the major superconducting magnet needs for the ILC as presently determined by the Area Systems Groups, responsible for beam line design, working with the Magnet Systems Group. The superconducting magnet components include Main Linac quadrupoles, Positron Source undulators, Damping Ring wigglers, a complex array of Final Focus superconducting elements in the Beam Delivery System, and large superconducting solenoids in the e{sup +} and e{sup -} Sources, and the Ring to Main Linac lines.

  13. An Undulator Based Polarized Positron Source for CLIC

    SciTech Connect (OSTI)

    Liu, Wanming; /Argonne; Gai, Wei; /Argonne; Rinolfi, Louis; /CERN; Sheppard, John; /SLAC

    2012-07-02T23:59:59.000Z

    A viable positron source scheme is proposed that uses circularly polarized gamma rays generated from the main 250 GeV electron beam. The beam passes through a helical superconducting undulator with a magnetic field of {approx} 1 Tesla and a period of 1.15 cm. The gamma-rays produced in the undulator in the energy range between {approx} 3 MeV - 100 MeV will be directed to a titanium target and produce polarized positrons. The positrons are then captured, accelerated and transported to a Pre-Damping Ring (PDR). Detailed parameter studies of this scheme including positron yield, and undulator parameter dependence are presented. Effects on the 250 GeV CLIC main beam, including emittance growth and energy loss from the beam passing through the undulator are also discussed.

  14. Status of the ILC Crab Cavity Development

    SciTech Connect (OSTI)

    Burt, G.; Dexter, A.; /Cockcroft Inst. Accel. Sci. Tech.; Beard, C.; Goudket, P.; McIntosh, P.; /Daresbury; Bellantoni, L.; /Fermilab; Grimm, T.; Li, Z.; Xiao, L.; /SLAC

    2011-10-20T23:59:59.000Z

    The International Linear Collider (ILC) will require two dipole cavities to 'crab' the electron and positron bunches prior to their collision. It is proposed to use two 9 cell SCRF dipole cavities operating at a frequency of 3.9 GHz, with a transverse gradient of 3.8MV/m in order to provide the required transverse kick. Extensive numerical modelling of this cavity and its couplers has been performed. Aluminium prototypes have been manufactured and tested to measure the RF properties of the cavity and couplers. In addition single cell niobium prototypes have been manufactured and tested in a vertical cryostat. The International Collider (ILC) [1] collides bunches of electrons and positrons at a crossing angle of 14 mrad. The angle between these bunches causes a loss in luminosity due to geometric effects [2]. The luminosity lost from this geometric effect can be recovered by rotating the bunches into alignment prior to collision. One possible method of rotating the bunches is to use a crab cavity [3]. A crab cavity is a transverse defecting cavity, where the phase of the cavity is such that the head and tail of the bunch receive equal and opposite kicks. As the bunches are only 500 nm wide in the horizontal plane, the cavity phase must be strictly controlled to avoid the bunch centre being deflected too much. In order to keep the phase stability within the required limits it is required that the cavity be superconducting to avoid thermal effects in both the cavity and its RF source. At the location of the crab cavity in the ILC there is only 23 cm separation between the centre of the cavity and the extraction line, hence the cavity must be small enough to fit in this space. This, along with the difficulty of making high frequency SRF components, set the frequency of the cavity to 3.9 GHz.

  15. HIGH INTENSITY LOW-ENERGY POSITRON SOURCE AT JEFFERSON

    SciTech Connect (OSTI)

    Serkan Golge, Bogdan Wojtsekhowski, Branislav Vlahovic

    2012-07-01T23:59:59.000Z

    We present a novel concept of a low-energy e{sup +} source with projected intensity on the order of 10{sup 10} slow e{sup +}/s. The key components of this concept are a continuous wave e{sup -} beam, a rotating positron-production target, a synchronized raster/anti-raster, a transport channel, and extraction of e{sup +} into a field-free area through a magnetic plug for moderation in a cryogenic solid. Components were designed in the framework of GEANT4-based (G4beamline) Monte Carlo simulation and TOSCA magnetic field calculation codes. Experimental data to demonstrate the effectiveness of the magnetic plug is presented.

  16. ILC Linac R&D at SLAC

    SciTech Connect (OSTI)

    Adolphsen, C.; /SLAC

    2006-08-09T23:59:59.000Z

    Since the ITRP recommendation in August 2004 to use superconducting rf technology for a next generation linear collider, the former NLC Group at SLAC has been actively pursuing a broad range of R&D for this collider (the ILC). In this paper, the programs concerning linac technology are reviewed. Current activities include the development of a Marx-style modulator and a 10 MW sheet-beam klystron, operation of an L-band (1.3 GHz) rf source using an SNS HVCM modulator and commercial klystrons, design of a more efficient and less costly rf distribution system, construction of a coupler component test stand, fabrication of a prototype positron capture cavity, beam tests of prototype S-band linac beam position monitors and preparations for magnetic center stability measurements of a prototype SC linac quad.

  17. Admittance Test and Conceptual Study of a CW Positron Source for CEBAF

    SciTech Connect (OSTI)

    Golge, Serkan [Department of Physics, Old Dominion University, Norfolk VA 23529 (United States); Hyde, Charles E. [Department of Physics, Old Dominion University, Norfolk VA 23529 (United States); Universite Blaise Pascal, Clermont-Ferrand (France); Freyberger, Arne [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States)

    2009-09-02T23:59:59.000Z

    A conceptual study of a Continuous Wave (CW) positron production is presented in this paper. The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLAB) operates with a CW electron beam with a well-defined emittance, time structure and energy spread. Positrons created via bremsstrahlung photons in a high-Z target emerge with a large emittance compared to incoming electron beam. An admittance study has been performed at CEBAF to estimate the maximum beam phase space area that can be transported in the LINAC and in the Arcs. A positron source is described utilizing the CEBAF injector electron beam, and directly injecting the positrons into the CEBAF LINAC.

  18. Proceedings of the workshop on new kinds of positron sources for linear colliders

    SciTech Connect (OSTI)

    Clendenin, J.; Nixon, R. [eds.

    1997-06-01T23:59:59.000Z

    It has been very clear from the beginning of studies for future linear colliders that the conventional positron source approach, as exemplified by the SLC source, is pushing uncomfortably close to the material limits of the conversion target. Nonetheless, since this type of positron source is better understood and relatively inexpensive to build, it has been incorporated into the initial design studies for the JLC/NLC. New ideas for positron sources for linear colliders have been regularly reported in the literature and at accelerator conferences for at least a decade, and indeed the recirculation scheme associated with the VLEPP design is nearly two decades old. Nearly all the new types of positron sources discussed in this workshop come under the heading of crystals (or channeling), undulators, and Compton. Storage ring and nuclear reactor sources were not discussed. The positron source designs that were discussed have varying degrees of maturity, but except for the case of crystal sources, where proof of principle experiments have been undertaken, experimental results are missing. It is hoped that these presentations, and especially the recommendations of the working groups, will prove useful to the various linear collider groups in deciding if and when new experimental programs for positron sources should be undertaken.

  19. Beam Dynamics Challenges for the ILC

    SciTech Connect (OSTI)

    Kubo, Kiyoshi; /KEK, Tsukuba; Seryi, Andrei; /SLAC; Walker, Nicholas; /DESY; Wolski, Andy; /Cockcroft Inst. Accel. Sci. Tech.

    2008-02-13T23:59:59.000Z

    The International Linear Collider (ILC) is a proposal for 500 GeV center-of-mass electron-positron collider, with a possible upgrade to {approx}1 TeV center-of-mass. At the heart of the ILC are the two {approx}12 km 1.3 GHz superconducting RF (SCRF) linacs which will accelerate the electron and positron beams to an initial maximum energy of 250 GeV each. The Global Design Effort (GDE)--responsible for the world-wide coordination of this uniquely international project--published the ILC Reference Design Report in August of 2007 [1]. The ILC outlined in the RDR design stands on a legacy of over fifteen-years of R&D. The GDE is currently beginning the next step in this ambitious project, namely an Engineering Design phase, which will culminate with the publication of an Engineering Design Report (EDR) in mid-2010. Throughout the history of linear collider development, beam dynamics has played an essential role. In particular, the need for complex computer simulations to predict the performance of the machine has always been crucial, not least because the parameters of the ILC represent in general a large extrapolation from where current machines operate today; many of the critical beam-dynamics features planned for the ILC can ultimately only be truly tested once the ILC has been constructed. It is for this reason that beam dynamics activities will continue to be crucial during the Engineering Design phase, as the available computer power and software techniques allow ever-more complex and realistic models of the machine to be developed. Complementary to the computer simulation efforts are the need for well-designed experiments at beam-test facilities, which--while not necessarily producing a direct demonstration of the ILC-like parameters for the reasons mentioned above--can provide important input and benchmarking for the computer models.

  20. A High Intensity Positron Source at Saclay: The SOPHI Project

    SciTech Connect (OSTI)

    Rey, J.-M.; Blideanu, V.; Carty, M.; Coulloux, G.; Curtoni, A.; Delferriere, O.; Liszkay, L.; Perez, P.; Ruiz, N.; Sauce, Y. [CEA-Saclay, DSM/IRFU, 91191 Gif sur Yvette (France); Forest, F.; Lancelot, J. L.; Neuveglise, D. [SIGMAPHI, Z.I. du Prat, Rue des freres Montgolfier, Vannes, Morbihan 56000 (France)

    2009-03-10T23:59:59.000Z

    We are building the SOPHI experiment in Saclay, which is a device based on a small 5 MeV electron linac to produce positrons via pair production on a tungsten target. This device should provide 10{sup 8} slow e{sup +}/s, i.e. a factor 300 greater than the strongest activity Na{sub 22} based setup. The SOPHI system has been finalized at the end of 2006 and the main components have been studied and built during 2007. The experiment is currently being assembled and first results are expected for autumn 2008. The electron linac, positron beam production and transport system will be presented, and expected positron production rate reported.

  1. ILC Reference Design Report: Accelerator Executive Summary

    SciTech Connect (OSTI)

    Phinney, Nan; /SLAC

    2007-12-14T23:59:59.000Z

    The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radiofrequency (SCRF) accelerating cavities. The use of the SCRF technology was recommended by the International Technology Recommendation Panel (ITRP) in August 2004 [1], and shortly thereafter endorsed by the International Committee for Future Accelerators (ICFA). In an unprecedented milestone in high-energy physics, the many institutes around the world involved in linear collider R&D united in a common effort to produce a global design for the ILC. In November 2004, the 1st International Linear Collider Workshop was held at KEK, Tsukuba, Japan. The workshop was attended by some 200 accelerator physicists from around the world, and paved the way for the 2nd ILC Workshop in August 2005, held at Snowmass, Colorado, USA, where the ILC Global Design Effort (GDE) was officially formed. The GDE membership reflects the global nature of the collaboration, with accelerator experts from all three regions (Americas, Asia and Europe). The first major goal of the GDE was to define the basic parameters and layout of the machine--the Baseline Configuration. This was achieved at the first GDE meeting held at INFN, Frascati, Italy in December 2005 with the creation of the Baseline Configuration Document (BCD). During the next 14 months, the BCD was used as the basis for the detailed design work and value estimate (as described in section 1.6) culminating in the completion of the second major milestone, the publication of the draft ILC Reference Design Report (RDR). The technical design and cost estimate for the ILC is based on two decades of world-wide Linear Collider R&D, beginning with the construction and operation of the SLAC Linear Collider (SLC). The SLC is acknowledged as a proof-of-principle machine for the linear collider concept. The ILC SCRF linac technology was pioneered by the TESLA collaboration*, culminating in a proposal for a 500 GeV center-of-mass linear collider in 2001 [2]. The concurrent (competing) design work on a normal conducting collider (NLC with X-band [3] and GLC with X- or C-Band [4]), has advanced the design concepts for the ILC injectors, Damping Rings (DR) and Beam Delivery System (BDS), as well as addressing overall operations, machine protection and availability issues. The X- and C-band R&D has led to concepts for the RF power source that may eventually produce either cost and/or performance benefits. Finally, the European XFEL [5] to be constructed at DESY, Hamburg, Germany, will make use of the TESLA linac technology, and represents a significant on-going R&D effort which remains of great benefit for the ILC. The current ILC baseline assumes an accelerating gradient of 31.5 MV/m to achieve a centre-of-mass energy of 500 GeV. The high luminosity requires the use of high power and small emittance beams. The choice of 1.3 GHz SCRF is well suited to the requirements, primarily because the very low power loss in the SCRF cavity walls allows the use of long RF pulses, relaxing the requirements on the peak-power generation, and ultimately leading to high wall-plug to beam transfer efficiency. The primary cost drivers are the SCRF Main Linac technology and the Conventional Facilities (including civil engineering). The choice of gradient is a key cost and performance parameter, since it dictates the length of the linacs, while the cavity quality factor (Q{sub 0}) relates to the required cryogenic cooling power. The achievement of 31.5 MV/m as the baseline average operational accelerating gradient--requiring a minimum performance of 35 MV/m during cavity mass-production acceptance testing--represents the primary challenge to the global ILC R&D With the completion of the RDR, the GDE will shortly begin an engineering design study, closely coupled with a prioritized R&D program. The goal is to produce an Engineering Design Report (EDR) demonstrating readiness for construction by 2010, followed by start of construction in 2012. A seve

  2. ILC Reference Design Report Volume 1 - Executive Summary

    E-Print Network [OSTI]

    Brau, James; Walker, Nicholas

    2007-01-01T23:59:59.000Z

    The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization.

  3. ILC Reference Design Report Volume 1 - Executive Summary

    E-Print Network [OSTI]

    James Brau; Yasuhiro Okada; Nicholas Walker

    2007-12-12T23:59:59.000Z

    The International Linear Collider (ILC) is a 200-500 GeV center-of-mass high-luminosity linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency (SCRF) accelerating cavities. The ILC has a total footprint of about 31 km and is designed for a peak luminosity of 2x10^34 cm^-2s^-1. This report is the Executive Summary (Volume I) of the four volume Reference Design Report. It gives an overview of the physics at the ILC, the accelerator design and value estimate, the detector concepts, and the next steps towards project realization.

  4. Wake potentials of the ILC Interaction Region

    SciTech Connect (OSTI)

    Novokhatski, A.; /SLAC

    2011-08-16T23:59:59.000Z

    The vacuum chamber of the ILC Interaction Region (IR) is optimized for best detector performance. It has special shaping to minimize additional backgrounds due to the metal part of the chamber. Also, for the same reason this thin vacuum chamber does not have water cooling. Therefore, small amounts of power, which may be deposited in the chamber, can be enough to raise the chamber to a high temperature. One of the sources of 'heating' power is the electromagnetic field of the beam. This field diffracts by non-regularities of the beam pipe and excites free-propagating fields, which are then absorbed by the pipe wall. In addition we have a heating power of the image currents due to finite conductivity of the metallic wall. We will discuss these effects as updating the previous results. The conclusions of this report are: (1) The amount of the beam energy loss in IR is almost equal to the energy loss in one ILC (TESLA) accelerating cryo-module; (2) Addition energy spread at IR is very small; (3) Spectrum of the wake fields is limited 300 GHz; (4) Average power of the wake fields excited in IR is 30 W for nominal ILC parameters; and (5) Pulse power in this case is 6 kilowatts.

  5. A table-top laser-based source of femtosecond, collimated, ultra-relativistic positron beams

    E-Print Network [OSTI]

    G. Sarri; W. Schumaker; A. Di Piazza; M. Vargas; B. Dromey; M. E. Dieckmann; V. Chvykov; A. Maksimchuk; V. Yanovsky; Z. H. He; B. X. Hou; J. A. Nees; A. G. R. Thomas; C. H. Keit; M. Zepf; K. Krushelnick

    2013-04-19T23:59:59.000Z

    The generation of ultra-relativistic positron beams with short duration ($\\tau_{e^+} \\leq 30$ fs), small divergence ($\\theta_{e^+} \\simeq 3$ mrad), and high density ($n_{e^+} \\simeq 10^{14} - 10^{15}$ cm$^{-3}$) from a fully optical setup is reported. The detected positron beam propagates with a high-density electron beam and $\\gamma$-rays of similar spectral shape and peak energy, thus closely resembling the structure of an astrophysical leptonic jet. It is envisaged that this experimental evidence, besides the intrinsic relevance to laser-driven particle acceleration, may open the pathway for the small-scale study of astrophysical leptonic jets in the laboratory.

  6. E166: Polarized Positrons & Polarimetry

    SciTech Connect (OSTI)

    Schuler, K.Peter; /DESY

    2011-12-06T23:59:59.000Z

    A proof-of-principle experiment has been carried out in the Final Focus Test Beam (FFTB) at Stanford Linear Accelerator Center (SLAC) to demonstrate production of polarized positrons in a manner suitable for implementation at the International Linear Collider (ILC). A helical undulator of 2.54 mm period and 1 -m length produced circularly polarized photons with a first harmonic endpoint energy of 8 MeV when traversed by a 46.6 GeV electron beam. The polarized photons were converted to polarized positrons in a 0.2-radiation-length tungsten target. The polarization of these positrons was measured using a Compton transmission polarimeter to have peak value in excess of 80%.

  7. Positrons for linear colliders

    SciTech Connect (OSTI)

    Ecklund, S.

    1987-11-01T23:59:59.000Z

    The requirements of a positron source for a linear collider are briefly reviewed, followed by methods of positron production and production of photons by electromagnetic cascade showers. Cross sections for the electromagnetic cascade shower processes of positron-electron pair production and Compton scattering are compared. A program used for Monte Carlo analysis of electromagnetic cascades is briefly discussed, and positron distributions obtained from several runs of the program are discussed. Photons from synchrotron radiation and from channeling are also mentioned briefly, as well as positron collection, transverse focusing techniques, and longitudinal capture. Computer ray tracing is then briefly discussed, followed by space-charge effects and thermal heating and stress due to showers. (LEW)

  8. A POSITRON SOURCE USING AN AXIALLY ORIENTED CRYSTAL ASSOCIATED TO A GRANULAR AMORPHOUS CONVERTER

    E-Print Network [OSTI]

    Boyer, Edmond

    and corresponding heating are analyzed and solutions for cooling are proposed. The configurations studied here]. For such device, called hybrid source, the amount of PEDD (Peak Energy Deposition Density) can be made lower than critical values (35 J/g, for W) avoiding the use ofa multi- target system; that was already proposed

  9. Converter-Modulator Design and Operations for the ILC L-band Test Stand

    SciTech Connect (OSTI)

    Reass, William A.; /Los Alamos; Burkhart, C.; Adolphsen, Chris E.; Beukers, T.; Cassel, R.; de Lira, A.; Papas, C.; Nguyen, M.; Went, R.; /SLAC; Anderson, David E.; /Oak

    2007-09-10T23:59:59.000Z

    To facilitate a rapid response to the International Linear Collider (ILC) L-band development program at SLAC, a spare converter-modulator was shipped from LANL. This modulator was to be a spare for the spallation neutron source (SNS) accelerator at ORNL. The ILC application requires a 33% higher peak output power (15 MW) and output current (120 Amp). This presents significant design challenges to modify the existing hardware and yet maintain switching parameters and thermal cycling within the semiconductor component ratings. To minimize IGBT commutation and free-wheeling diode currents, a different set of optimizations, as compared to the SNS design, were used to tune the resonant switching networks. Additional complexities arose as nanocrystalline cores with different performance characteristics (as compared to SNS), were used to fabricate the resonant 'boost' transformers. This paper will describe the electrical design, modeling efforts, and resulting electrical performance as implemented for the ILC L-band test stand.

  10. accelerator ilc budowa: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Paper HEP - Phenomenology (arXiv) Summary: The ILC Higgs White Paper is a review of Higgs Boson theory and experiment at the International Linear Collider (ILC). Theory topics...

  11. akceleratorze liniowym ilc: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Paper HEP - Phenomenology (arXiv) Summary: The ILC Higgs White Paper is a review of Higgs Boson theory and experiment at the International Linear Collider (ILC). Theory topics...

  12. Discovering bottom squark coannihilation at the ILC

    SciTech Connect (OSTI)

    Belyaev, Alexander; Lastovicka, Tomas; Nomerotski, Andrei; Lastovicka-Medin, Gordana [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom) and Particle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); University of Montenegro, Cetinjska bb, 81 000 Podgorica (Montenegro)

    2010-02-01T23:59:59.000Z

    We study the potential of the international linear collider (ILC) at {radical}(s)=500 GeV to probe new dark matter motivated scenario where the bottom squark (sbottom) is the next-to-lightest supersymmetric particle. For this scenario, which is virtually impossible for the LHC to test, the ILC has a potential to cover a large fraction of the parameter space. The challenge is due to a very low energy of jets, below 20-30 GeV, which pushes the jet clustering and flavor tagging algorithms to their limits. The process of sbottom pair production was studied within the SiD detector concept. We demonstrate that ILC offers a unique opportunity to test the supersymmetry parameter space motivated by the sbottom-neutralino coannihilation scenario in cases when the sbottom production is kinematically accessible. The study was done with the full SiD simulation and reconstruction chain including all standard model and beam backgrounds.

  13. Updated Results of a Solid-State Sensor Irradiation Study for ILC Extreme Forward Calorimetry

    E-Print Network [OSTI]

    Courcoubetis, George; Fadeyev, Vitaliy; Kelley, Thomas; Martinez-McKinney, Forest; Schumm, Bruce A; Spencer, Edwin; Tang, Vivian; Wilder, Max

    2015-01-01T23:59:59.000Z

    Detectors proposed for the International Linear Collider (ILC) incorporate a tungsten sampling calorimeter (`BeamCal') intended to reconstruct showers of electrons, positrons and photons that emerge from the interaction point of the collider with angles between 5 and 50 milliradians. For the innermost radius of this calorimeter, radiation doses at shower-max are expected to reach 100 MRad per year, primarily due to minimum-ionizing electrons and positrons that arise in the induced electromagnetic showers of e+e- `beamstrahlung' pairs produced in the ILC beam-beam interaction. However, radiation damage to calorimeter sensors may be dominated by hadrons induced by nuclear interactions of shower photons, which are much more likely to contribute to the non-ionizing energy loss that has been observed to damage sensors exposed to hadronic radiation. We report here on the results of SLAC Experiment T-506, for which several different types of silicon diode and gallium-arsenide sensors were exposed to doses of radiati...

  14. ILC Vertex Tracker R&D

    SciTech Connect (OSTI)

    Battaglia, Marco; Bussat, Jean-Marie; Contarato, Devis; Denes,Peter; Glesener, Lindsay; Greiner, Leo; Hooberman, Benjamin; Shuman,Derek; Tompkins, Lauren; Vu, Chinh; Bisello, Dario; Giubilato, Piero; Pantano, Devis; Costa, Marco; La Rosa, Alessandro; Bolla, Gino; Bortoletto, Daniela; Children, Isaac

    2007-10-01T23:59:59.000Z

    This document summarizes past achievements, current activities and future goals of the R&D program aimed at the design, prototyping and characterization of a full detector module, equipped with monolithic pixel sensors, matching the requirements for the Vertex Tracker at the ILC. We provide a plan of activities to obtain a demonstrator multi-layered vertex tracker equipped with sensors matching the ILC requirements and realistic lightweight ladders in FY11, under the assumption that ILC detector proto-collaborations will be choosing technologies and designs for the Vertex Tracker by that time. The R&D program discussed here started at LBNL in 2004, supported by a Laboratory Directed R&D (LDRD) grant and by funding allocated from the core budget of the LBNL Physics Division and from the Department of Physics at UC Berkeley. Subsequently additional funding has been awarded under the NSF-DOE LCRD program and also personnel have become available through collaborative research with other groups. The aim of the R&D program carried out by our collaboration is to provide a well-integrated, inclusive research effort starting from physics requirements for the ILC Vertex Tracker and addressing Si sensor design and characterization, engineered ladder design, module system issues, tracking and vertex performances and beam test validation. The broad scope of this program is made possible by important synergies with existing know-how and concurrent programs both at LBNL and at the other collaborating institutions. In particular, significant overlaps with LHC detector design, SLHC R&D as well as prototyping for the STAR upgrade have been exploited to optimize the cost per deliverable of our program. This activity is carried out as a collaborative effort together with Accelerator and Fusion Research, the Engineering and the Nuclear Science Divisions at LBNL, INFN and the Department of Physics in Padova, Italy, INFN and the Department of Physics in Torino, Italy and the Department of Physics of Purdue University.

  15. Methods and apparatus for producing and storing positrons and protons

    DOE Patents [OSTI]

    Akers, Douglas W. (Idaho Falls, ID)

    2010-07-06T23:59:59.000Z

    Apparatus for producing and storing positrons may include a trap that defines an interior chamber therein and that contains an electric field and a magnetic field. The trap may further include a source material that includes atoms that, when activated by photon bombardment, become positron emitters to produce positrons. The trap may also include a moderator positioned adjacent the source material. A photon source is positioned adjacent the trap so that photons produced by the photon source bombard the source material to produce the positron emitters. Positrons from the positron emitters and moderated positrons from the moderator are confined within the interior chamber of the trap by the electric and magnetic fields. Apparatus for producing and storing protons are also disclosed.

  16. Nondestructive examination using neutron activated positron annihilation

    DOE Patents [OSTI]

    Akers, Douglas W. (Idaho Falls, ID); Denison, Arthur B. (Idaho Falls, ID)

    2001-01-01T23:59:59.000Z

    A method is provided for performing nondestructive examination of a metal specimen using neutron activated positron annihilation wherein the positron emitter source is formed within the metal specimen. The method permits in situ nondestructive examination and has the advantage of being capable of performing bulk analysis to determine embrittlement, fatigue and dislocation within a metal specimen.

  17. $Z'$ resonance and associated $Zh$ production at future Higgs boson factory: ILC and CLIC

    E-Print Network [OSTI]

    Gutierrez-Rodriguez, A

    2015-01-01T23:59:59.000Z

    We study the prospects of the B-L model with an additional $Z'$ boson to be a Higgs boson factory at high-energy and high-luminosity linear electron positron colliders, such as the ILC and CLIC, through the Higgs-strahlung process $e^{+}e^{-}\\rightarrow (Z, Z') \\to Zh$, including both the resonant and non-resonant effects. We evaluate the total cross section of $Zh$ and we calculate the total number of events for integrated luminosities of 500-2000\\hspace{0.8mm}$fb^{-1}$ and center of mass energies between 500 and 3000\\hspace{0.8mm}$GeV$. We find that the total number of expected $Zh$ events can reach $10^6$, which is a very optimistic scenario and it would be possible to perform precision measurements for both the $Z'$ and Higgs boson in future high-energy $e^+e^-$ colliders experiments.

  18. Measuring BR($h \\to \\tau ^+ \\tau ^-$) at the ILC: a full simulation study

    E-Print Network [OSTI]

    Kawada, Shin-ichi; Suehara, Taikan; Takahashi, Tohru; Tanabe, Tomohiko; Yokoyama, Harumichi

    2015-01-01T23:59:59.000Z

    We evaluate the expected measurement accuracy of the branching ratio of the Standard Model Higgs boson decaying into tau pairs at the ILC with a full simulation of the ILD detector concept. We assume a Higgs mass of 125 GeV, a branching ratio of BR($h \\to \\tau ^+ \\tau ^-$) = 6.32%, a beam polarization of electron (positron) of -0.8(+0.3), and an integrated luminosity of 250 fb$^{-1}$. The Higgs-strahlung process $e^+ e^- \\to Zh$ with $Z \\to q\\overline{q}$ is analyzed. We estimate the measurement accuracy of the branching ratio $\\Delta (\\sigma \\times \\mathrm{BR}) / (\\sigma \\times \\mathrm{BR})$ to be 3.4% with using a multivariate analysis technique.

  19. Coherent Instabilities of ILC Damping Ring

    SciTech Connect (OSTI)

    Heifets, S.; Stupakov, G.; Bane, K.; /SLAC

    2006-09-27T23:59:59.000Z

    The paper presents the first attempt to estimates the ILC damping ring impedance and compare thresholds of the classical instabilities for several designs initially proposed for the DR. The work was carried out in the spring of 2006. Since then the choice of the DR is narrowed. Nevertheless, the analysis described may be useful for the next iterations of the beam stability. Overall, the conventional instabilities will have little impact on the ring performance provided the careful design of the ring minimizes the impedance below acceptable level indicated above. The only exception is the transverse CB instability. The longitudinal CB is less demanding. However, even the transverse CB instability would have threshold current above nominal provided the aperture in the wigglers is increased from 8 mm to 16 mm. The microwave instability needs more studies. Nevertheless, we should remember that the ILC DR is different from existing high-current machines at least in two respects: absence of the beam-beam tune spread stabilizing beams in colliders, and unusual strict requirements for low emittance. That may cause new problems such as bunch emittance dilution due to high-frequency wakes (BPMs, grooves), etc. Even if such a possibility exists, it probably universal for all machines and ought be addressed in the design of vacuum components rather than have effect on the choice of the machine design.

  20. Preliminary Report on the Evaluation of an Electron-Positron Collider as a source of Monoenergetic Photons

    SciTech Connect (OSTI)

    Fast, James E.; Campbell, Luke W.

    2009-11-30T23:59:59.000Z

    Abstract Active interrogation methods are being investigated to detect shielded special nuclear material (SNM). These approaches utilize either neutron or photon beams to excite the SNM in concert with either neutron or gamma ray detectors to observe the stimulated emissions. The two primary methodologies with photon beams are photofission and nuclear resonance florescence (NRF). Photofission requires photons energies of 7-10 MeV while NRF requires photon energies around 2 MeV. For both techniques, photons that are not in the appropriate energy band, e.g. the low energy tail of a Bremsstrahlung photon beam, contribute unwanted additional radiation dose to cargo. Typically less than 10% of the photons are in the usable energy band. The additional photon production generates a commensurate amount of additional radiation dose in the source and target areas, impacting shielding requirements and/or dose to operators and equipment and at the expense of a similar increase in power consumption. Hence it is highly desirable to produce narrow energy (“monoenergetic”) photon beams with tunable energy in the range of ~2-20 MeV.

  1. The E166 Experiment: Undulator-Based Production of Polarized Positrons

    SciTech Connect (OSTI)

    Schuler, K.Peter; /DESY

    2007-10-29T23:59:59.000Z

    A proof-of-principle experiment has been carried out in the Final Focus Test Beam (FFTB) at SLAC to demonstrate production of polarized positrons in a manner suitable for implementation at the ILC. A helical undulator of 2.54 mm period and 1-m length produced circularly polarized photons of first harmonic endpoint energy of 8 MeV when traversed by a 46.6 GeV electron beam. The polarized photons were converted to polarized positrons in a 0.2-radiation-length tungsten target. The polarization of these positrons was measured at several energies, with a peak value of {approx} 80% according to a preliminary analysis of the transmission polarimetry of photons obtained on reconversion of the positrons in a second tungsten target.

  2. The E166 Experiment: Undulator-Based Production of Polarized Positrons

    SciTech Connect (OSTI)

    Schueler, K. Peter [DESY, D-22607 Hamburg (Germany)

    2008-02-06T23:59:59.000Z

    A proof-of-principle experiment has been carried out in the Final Focus Test Beam (FFTB) at SLAC to demonstrate production of polarized positrons in a manner suitable for implementation at the ILC. A helical undulator of 2.54 mm period and 1-m length produced circularly polarized photons of first harmonic endpoint energy of 8 MeV when traversed by a 46.6 GeV electron beam. The polarized photons were converted to polarized positrons in a 0.2-radiation-length tungsten target. The polarization of these positrons was measured at several energies, with a peak value in excess of 80%, by transmission polarimetry of photons obtained on reconversion of the positrons in a second tungsten target.

  3. Design of the ILC RTML extraction lines

    SciTech Connect (OSTI)

    Seletskiy, S.; Tenenbaum, P.; Walz, D.; /SLAC; Solyak, N.; /Fermilab

    2008-06-01T23:59:59.000Z

    The ILC [1] Damping Ring to the Main Linac beamline (RTML) contains three extraction lines (EL). Each EL can be used both for an emergency abort dumping of the beam and tune-up continual train-by-train extraction. Two of the extraction lines are located downstream of the first and second stages of the RTML bunch compressor, and must accept both compressed and uncompressed beam with energy spreads of 2.5% and 0.15%, respectively. In this paper we report on an optics design that allowed minimizing the length of the extraction lines while offsetting the beam dumps from the main line by the distance required for acceptable radiation levels in the service tunnel. The proposed extraction lines can accommodate beams with different energy spreads while at the same time providing the beam size acceptable for the aluminum dump window.

  4. ILC Marx Modulator Development Program Status

    SciTech Connect (OSTI)

    Burkhart, C.; Beukers, T.; Larsen, R.; Macken, K.; Nguyen, M.; Olsen, J.; Tang, T.; /SLAC

    2009-03-04T23:59:59.000Z

    Development of a first generation prototype (P1) Marx-topology klystron modulator for the International Linear Collider is nearing completion at the Stanford Linear Accelerator Center. It is envisioned as a smaller, lower cost, and higher reliability alternative to the present, bouncer-topology, 'Baseline Conceptual Design'. The Marx presents several advantages over conventional klystron modulator designs. It is physically smaller; there is no pulse transformer (quite massive at ILC parameters) and the energy storage capacitor bank is quite small, owing to the active droop compensation. It is oil-free; voltage hold-off is achieved using air insulation. It is air cooled; the secondary air-water heat exchanger is physically isolated from the electronic components. The P1-Marx employs all solid state elements; IGBTs and diodes, to control the charge, discharge and isolation of the cells. A general overview of the modulator design and the program status are presented.

  5. ILC RF System R and D

    SciTech Connect (OSTI)

    Adolphsen, Chris; /SLAC

    2012-07-03T23:59:59.000Z

    The Linac Group at SLAC is actively pursuing a broad range of R&D to improve the reliability and reduce the cost of the L-band (1.3 GHz) rf system proposed for the ILC linacs. Current activities include the long-term evaluation of a 120 kV Marx Modulator driving a 10 MW Multi-Beam Klystron, design of a second-generation Marx Modulator, testing of a sheet-beam gun and beam transport system for a klystron, construction of an rf distribution system with remotely-adjustable power tapoffs, and development of a system to combine the power from many klystrons in low-loss circular waveguide where it would be tapped-off periodically to power groups of cavities. This paper surveys progress during the past few years.

  6. Model-independent WIMP Searches at the ILC

    E-Print Network [OSTI]

    Bartels, C

    2007-01-01T23:59:59.000Z

    We investigate the possibility to detect WIMPs at the ILC in a model-independent way using events with single photons. The study is done with a full detector simulation of the LDC detector and MarlinReco. It turns out that WIMPs are observable this way at the ILC if their coupling to electrons is not too small. Beam polarisation can increase the accessible phase space significantly.

  7. Model-independent WIMP Searches at the ILC

    E-Print Network [OSTI]

    C. Bartels; J. List

    2007-09-17T23:59:59.000Z

    We investigate the possibility to detect WIMPs at the ILC in a model-independent way using events with single photons. The study is done with a full detector simulation of the LDC detector and MarlinReco. It turns out that WIMPs are observable this way at the ILC if their coupling to electrons is not too small. Beam polarisation can increase the accessible phase space significantly.

  8. Cosmic-ray positrons from millisecond pulsars

    E-Print Network [OSTI]

    Venter, C; Harding, A K; Gonthier, P L; Büsching, I

    2015-01-01T23:59:59.000Z

    Observations by the Fermi Large Area Telescope of gamma-ray millisecond pulsar light curves imply copious pair production in their magnetospheres, and not exclusively in those of younger pulsars. Such pair cascades may be a primary source of Galactic electrons and positrons, contributing to the observed enhancement in positron flux above ~10 GeV. Fermi has also uncovered many new millisecond pulsars, impacting Galactic stellar population models. We investigate the contribution of Galactic millisecond pulsars to the flux of terrestrial cosmic-ray electrons and positrons. Our population synthesis code predicts the source properties of present-day millisecond pulsars. We simulate their pair spectra invoking an offset-dipole magnetic field. We also consider positrons and electrons that have been further accelerated to energies of several TeV by strong intrabinary shocks in black widow and redback systems. Since millisecond pulsars are not surrounded by pulsar wind nebulae or supernova shells, we assume that the p...

  9. Higher Order Mode Heating Analysis for the ILC Superconducting Linacs

    SciTech Connect (OSTI)

    Bane, K.L.F.; Nantista, C.; Adolphsen, C.; /SLAC; ,

    2010-10-27T23:59:59.000Z

    The superconducting cavities and interconnects in the 11 km long linacs of the International Linear Collider (ILC) are designed to operate at 2K, where cooling costs are very expensive. It is thus important to minimize cryogenic heat loads. In addition to an unavoidable static load and the dynamic load of the fundamental 1.3 GHz accelerating rf, a further heat source is presented by the higher order mode (HOM) power deposited by the beam. Such modes will be damped by specially designed HOM couplers attached to the cavities (for trapped modes), and by ceramic dampers at 70K that are located between the eight or nine cavity cryomodules (for propagating modes). Brute force calculation of the higher frequency modes excited in a string of cryomodules is limited by computing capacity (see, e.g. [1]). M. Liepe has calculated {approx} 400 longitudinal TM modes in 3 superconducting cavities plus absorbers, up to 8 GHz [2]. Joestingmeier, et al., have used a ray tracing calculation to find the effect at higher frequencies, specifically in the range of tens of GHz and above [3]. In this report we present a scattering matrix approach, which we apply to an rf unit comprising 26 cavities and 3 absorbers. We perform calculations at sample frequencies (up to 20 GHz) to predict the effectiveness of the ceramic dampers in limiting HOM heat deposition at 2K.

  10. Apparatus for photon activation positron annihilation analysis

    DOE Patents [OSTI]

    Akers, Douglas W. (Idaho Falls, ID)

    2007-06-12T23:59:59.000Z

    Non-destructive testing apparatus according to one embodiment of the invention comprises a photon source. The photon source produces photons having predetermined energies and directs the photons toward a specimen being tested. The photons from the photon source result in the creation of positrons within the specimen being tested. A detector positioned adjacent the specimen being tested detects gamma rays produced by annihilation of positrons with electrons. A data processing system operatively associated with the detector produces output data indicative of a lattice characteristic of the specimen being tested.

  11. ILC MARX MODULATOR DEVELOPMENT PROGRAM STATUS

    SciTech Connect (OSTI)

    Burkhart, Craig; Benwell, Andrew; Beukers, Tony; Kemp, Mark; Larsen, Raymond; MacNair, David; Nguyen, Minh; Olsen, Jeff; Tang, Tao; /SLAC

    2010-08-25T23:59:59.000Z

    A Marx-topology klystron modulator is under development for the International Linear Collider (ILC) project. It is envisioned as a lower cost, smaller footprint, and higher reliability alternative to the present, bouncer-topology, baseline design. The application requires 120 kV (+/-0.5%), 140 A, 1.6 ms pulses at a rate of 5 Hz. The Marx constructs the high voltage pulse by combining, in series, a number of lower voltage cells. The Marx employs solid state elements; IGBTs and diodes, to control the charge, discharge and disolation of the cells. Active compensation of the output is used to achieve the voltage regulation while minimizing the stored energy. The developmental testing of a first generation prototype, P1, has been completed. This modulator has been integrated into a test stand with a 10 MW L-band klystron, where each is undergoing life testing. Development of a second generation prototype, P2, is underway. The P2 is based on the P1 topology but incorporates an alternative cell configuration to increase redundancy and improve availability. Status updates for both prototypes are presented.

  12. Development Status of the ILC Marx Modulator

    SciTech Connect (OSTI)

    Nguyen, M.; Beukers, T.; Burkhart, C.; Larsen, R.; Olsen, J.; Tang, T.; /SLAC

    2008-06-16T23:59:59.000Z

    The ILC Marx Modulator is under development as a lower cost alternative to the 'Baseline Conceptual Design' (BCD) klystron modulator. Construction of a prototype Marx is complete and testing is underway at SLAC. The Marx employs solid state elements, IGBTs and diodes, to control the charge, discharge and isolation of the modules. The prototype is based on a stack of sixteen modules, each initially charged to {approx}11 kV, which are arranged in a Marx topology. Initially, eleven modules combine to produce the 120 kV output pulse. The remaining modules are switched in after appropriate delays to compensate for the voltage droop that results from the discharge of the energy storage capacitors. Additional elements will further regulate the output voltage to {+-} 0.5%. The Marx presents several advantages over the conventional klystron modulator designs. It is physically smaller; there is no pulse transformer (quite massive at these parameters) and the energy storage capacitor bank is quite small, owing to the active droop compensation. It is oil-free; voltage hold-off is achieved using air insulation. It is air cooled; the secondary air-water heat exchanger is physically isolated from the electronic components. This paper outlines the current developmental status of the prototype Marx. It presents a detailed electrical and mechanical description of the modulator and operational test results. It will discuss electrical efficiency measurements, fault testing, and output voltage regulation.

  13. Development Status of The ILC Marx Modulator

    SciTech Connect (OSTI)

    Nguyen, M; Beukers, T.; Burkhart, C.; Larsen, R.; Olsen, J.; Tang, T.; /SLAC; ,

    2010-06-07T23:59:59.000Z

    The ILC Marx Modulator is under development as a lower cost alternative to the 'Baseline Conceptual Design' (BCD) klystron modulator. Construction of a prototype Marx is complete and testing is underway at SLAC. The Marx employs solid state elements, IGBTs and diodes, to control the charge, discharge and isolation of the modules. The prototype is based on a stack of sixteen modules, each initially charged to {approx}11 kV, which are arranged in a Marx topology. Initially, eleven modules combine to produce the 120 kV output pulse. The remaining modules are switched in after appropriate delays to compensate for the voltage droop that results from the discharge of the energy storage capacitors. Additional elements will further regulate the output voltage to {+-}0.5%. The Marx presents several advantages over the conventional klystron modulator designs. It is physically smaller; there is no pulse transformer (quite massive at these parameters) and the energy storage capacitor bank is quite small, owing to the active droop compensation. It is oil-free; voltage hold-off is achieved using air insulation. It is air cooled; the secondary air-water heat exchanger is physically isolated from the electronic components. This paper outlines the current developmental status of the prototype Marx. It presents a detailed electrical and mechanical description of the modulator and operational test results. It will discuss electrical efficiency measurements, fault testing, and output voltage regulation.

  14. P1-Marx Modulator for the ILC

    SciTech Connect (OSTI)

    Beukers, T.; Burkhart, C.; Kemp, M.; Larsen, R.; Nguyen, M.; Olsen, J.; Tang, T.; /SLAC

    2010-08-26T23:59:59.000Z

    A first generation prototype, P1, Marx-topology klystron modulator has been developed at the SLAC National Accelerator Laboratory for the International Linear Collider (ILC) project. It is envisioned as a lower cost, smaller footprint, and higher reliability alternative to the present, bouncer-topology, baseline design. The application requires 120 kV (+/-0.5%), 140 A, 1.6 ms pulses at a rate of 5 Hz. The Marx constructs the high voltage pulse by combining, in series, a number of lower voltage cells. The Marx employs solid state elements; IGBTs and diodes, to control the charge, discharge and isolation of the cells. Active compensation of the output is used to achieve the voltage regulation while minimizing the stored energy. The P1-Marx has been integrated into a test stand with a 10 MW L-band klystron, where each is undergoing life testing. A review of the P1-Marx design and its operational history in the L-band test stand are presented.

  15. THE BASELINE POSITRON PRODUCTION AND CAPTURE SCHEME FOR CLIC

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    THE BASELINE POSITRON PRODUCTION AND CAPTURE SCHEME FOR CLIC O. Dadoun , I. Chaikovska, P. Lepercq chan- neling as the baseline for unpolarised positron production. The hybrid source uses a few GeV electron beam imping- ing on a tungsten crystal target. With the crystal oriented on its axis

  16. ILC Electron Source Gets Help from JLab | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh School footballHydrogen andHypernuclei in Hall link toall2,

  17. Present Status of the ILC Project and Development

    SciTech Connect (OSTI)

    Ross, M.; /Fermilab; Walker, N.; /DESY; Yamamoto, A.; /KEK, Tsukuba

    2011-09-01T23:59:59.000Z

    The Technical Design of the International Linear Collider (ILC) Project will be finished in late 2012. The Technical Design Report (TDR) will include a description of the updated design, with a cost estimate and a project plan, and the results of research and development (R & D) done in support of the ILC. Results from directed ILC R & D are used to reduce the cost and risk associated with the ILC design. We present a summary of key challenges and show how the global R & D effort has addressed them. The most important activity has been in pursuit of very high gradient superconducting RF linac technology. There has been excellent progress toward the goal of practical industrial production of niobium sheet-metal cavities with gradient performance in excess of 35 MV/m. In addition, three purpose-built beam test facilities have been constructed and used to study and demonstrate high current linac performance, electron-cloud beam dynamics and precision beam control. The report also includes a summary of component design studies and conventional facilities cost optimization design studies.

  18. Design of the ILC RTML Extraction Lines

    SciTech Connect (OSTI)

    Seletskiy, S.; Tenenbaum, P.; Walz, D.; /SLAC; Solyak, N.; /Fermilab

    2011-10-17T23:59:59.000Z

    The ILC [1] Damping Ring to the Main Linac beamline (RTML) contains three extraction lines (EL). Each EL can be used both for an emergency abort dumping of the beam and tune-up continual train-by-train extraction. Two of the extraction lines are located downstream of the first and second stages of the RTML bunch compressor, and must accept both compressed and uncompressed beam with energy spreads of 2.5% and 0.15%, respectively. In this paper we report on an optics design that allowed minimizing the length of the extraction lines while offsetting the beam dumps from the main line by the distance required for acceptable radiation levels in the service tunnel. The proposed extraction lines can accommodate beams with different energy spreads while at the same time providing the beam size acceptable for the aluminum dump window. The RTML incorporates three extraction lines, which can be used for either an emergency beam abort or for a train-by-train extraction. The first EL is located downstream of the Damping Ring extraction arc. The other two extraction lines are located downstream of each stage of the two-stage bunch compressor. The first extraction line (EL1) receives 5GeV beam with an 0.15% energy spread. The extraction line located downstream of the first stage of bunch compressor (ELBC1) receives both compressed and uncompressed beam, and therefore must accept beam with both 5 and 4.88GeV energy, and 0.15% and 2.5% energy spread, respectively. The extraction line located after the second stage of the bunch compressor (ELBC2) receives 15GeV beam with either 0.15 or 1.8% energy spread. Each of the three extraction lines is equipped with the 220kW aluminum ball dump, which corresponds to the power of the continuously dumped beam with 5GeV energy, i.e., the beam trains must be delivered to the ELBC2 dump at reduced repetition rate.

  19. automated radiation targeting: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    diffraction radiation (ODR) as a diagnostic tool has increased Sen, Tanaji 9 Radiation damage of the ILC positron source target CERN Preprints Summary: The radiation damage of the...

  20. Making Relativistic Positrons Using Ultra-Intense Short Pulse Lasers

    SciTech Connect (OSTI)

    Chen, H; Wilks, S; Bonlie, J; Chen, C; Chen, S; Cone, K; Elberson, L; Gregori, G; Liang, E; Price, D; Van Maren, R; Meyerhofer, D D; Mithen, J; Murphy, C V; Myatt, J; Schneider, M; Shepherd, R; Stafford, D; Tommasini, R; Beiersdorfer, P

    2009-08-24T23:59:59.000Z

    This paper describes a new positron source produced using ultra-intense short pulse lasers. Although it has been studied in theory since as early as the 1970s, the use of lasers as a valuable new positron source was not demonstrated experimentally until recent years, when the petawatt-class short pulse lasers were developed. In 2008 and 2009, in a series of experiments performed at Lawrence Livermore National Laboratory, a large number of positrons were observed after shooting a millimeter thick solid gold target. Up to 2 x 10{sup 10} positrons per steradian ejected out the back of {approx}mm thick gold targets were detected. The targets were illuminated with short ({approx}1 ps) ultra-intense ({approx}1 x 10{sup 20} W/cm{sup 2}) laser pulses. These positrons are produced predominantly by the Bethe-Heitler process, and have an effective temperature of 2-4 MeV, with the distribution peaking at 4-7 MeV. The angular distribution of the positrons is anisotropic. For a wide range of applications, this new laser based positron source with its unique characteristics may complements the existing sources using radioactive isotopes and accelerators.

  1. High Availability Instrumentation Packaging Standards for the ILC and Detectors

    SciTech Connect (OSTI)

    Downing, R.W.; Larsen, R.S.; /SLAC

    2006-11-30T23:59:59.000Z

    ILC designers are exploring new packaging standards for Accelerator Controls and Instrumentation, particularly high-speed serial interconnect systems for intelligent instruments versus the existing parallel backplanes of VME, VXI and CAMAC. The High Availability Advanced Telecom Computing Architecture (ATCA) system is a new industrial open standard designed to withstand single-point hardware or software failures. The standard crate, controller, applications module and sub-modules are being investigated. All modules and sub-modules are hot-swappable. A single crate is designed for a data throughput in communications applications of 2 Tb/s and an Availability of 0.99999, which translates into a downtime of five minutes per year. The ILC is planning to develop HA architectures for controls, beam instrumentation and detector systems.

  2. Introduction to Positron Emission Tomography

    E-Print Network [OSTI]

    Oakes, Terry

    range: 1-10 mm Gamma-Ray range: 10 mm - 8 positron annihilation #12;Positron Emission Tomography #12;P.E.T. measures Concentration of Radioactivity 1) Gamma-rays escape from body: External detection possible. 2) Two gamma rays emitted at 180 when a positron annihilates: The annihilation occured somewhere

  3. The multi-scattering model for calculations of positron spatial distribution in the multilayer stacks, useful for conventional positron measurements

    SciTech Connect (OSTI)

    Dryzek, Jerzy [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland) [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland); Institute of Physics, Opole University, ul. Oleska 48, 45-052 Opole (Poland); Siemek, Krzysztof [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland)] [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland)

    2013-08-21T23:59:59.000Z

    The spatial distribution of positrons emitted from radioactive isotopes into stacks or layered samples is a subject of the presented report. It was found that Monte Carlo (MC) simulations using GEANT4 code are not able to describe correctly the experimental data of the positron fractions in stacks. The mathematical model was proposed for calculations of the implantation profile or positron fractions in separated layers or foils being components of a stack. The model takes into account only two processes, i.e., the positron absorption and backscattering at interfaces. The mathematical formulas were applied in the computer program called LYS-1 (layers profile analysis). The theoretical predictions of the model were in the good agreement with the results of the MC simulations for the semi infinite sample. The experimental verifications of the model were performed on the symmetrical and non-symmetrical stacks of different foils. The good agreement between the experimental and calculated fractions of positrons in components of a stack was achieved. Also the experimental implantation profile obtained using the depth scanning of positron implantation technique is very well described by the theoretical profile obtained within the proposed model. The LYS-1 program allows us also to calculate the fraction of positrons which annihilate in the source, which can be useful in the positron spectroscopy.

  4. DETECTORS, SAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSION TOMOGRAPHY

    E-Print Network [OSTI]

    Derenzo, S.E.

    2010-01-01T23:59:59.000Z

    SAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSIONSAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSIONSAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSION

  5. The Higgs sector of the NMFV MSSM at the ILC

    E-Print Network [OSTI]

    Arana-Catania, M; Herrero, M J; Penaranda, S

    2012-01-01T23:59:59.000Z

    We calculate the one-loop corrections to the Higgs boson masses within the context of the MSSM with Non-Minimal Flavor Violation in the squark sector. We take into account all the relevant restrictions from BR(B -> X_s gamma), BR(B_s -> mu^+ mu^-) and \\Delta M_{B_s}. We find sizable corrections to the lightest Higgs boson mass that are considerably larger than the expected ILC precision for acceptable values of the mixing parameters deltas. We find delta^{LR}_{ct} and delta^{RL}_{ct} specially relevant, mainly at low tan beta.

  6. Design of the Second-Generation ILC Marx Modulator

    SciTech Connect (OSTI)

    Kemp, M.A.; Benwell, A.; Burkhart, C.; Larsen, R.; MacNair, D.; Nguyen, M.; Olsen, J.; /SLAC; ,

    2010-09-14T23:59:59.000Z

    SLAC National Accelerator Laboratory (SLAC) has initiated a program to design and build a Marx-topology modulator to produce a relatively compact, low-cost, high availability klystron modulator for the International Linear Collider (ILC). Building upon the success of the P1 Marx, the SLAC P2 Marx is a second-generation modulator whose design further emphasizes the qualities of modularity and high-availability. This paper outlines highlights of this design and presents single-cell performance data obtained during the proof-of-concept phase of the project.

  7. The Reference Design for the ILC, Costs, and What's Next

    SciTech Connect (OSTI)

    Barish, Barry

    2007-03-26T23:59:59.000Z

    A Reference Design for the International Linear Collider was recently released. The scale of the ILC is such that it must be built by an international collaboration and the design is the culmination of a unique global effort. Through ICFA, a decision was made to base the design on superconducting RF technology and then the Global Design Effort (GDE) was created to coordinate the actual accelerator design toward a construction proposal. The reference design establishes all the features of the machine, and defines both the R&D program and engineering design that will now follow over the next few years.

  8. Positron lifetime spectrometer using a DC positron beam

    DOE Patents [OSTI]

    Xu, Jun; Moxom, Jeremy

    2003-10-21T23:59:59.000Z

    An entrance grid is positioned in the incident beam path of a DC beam positron lifetime spectrometer. The electrical potential difference between the sample and the entrance grid provides simultaneous acceleration of both the primary positrons and the secondary electrons. The result is a reduction in the time spread induced by the energy distribution of the secondary electrons. In addition, the sample, sample holder, entrance grid, and entrance face of the multichannel plate electron detector assembly are made parallel to each other, and are arranged at a tilt angle to the axis of the positron beam to effectively separate the path of the secondary electrons from the path of the incident positrons.

  9. Coaxial Coupling Scheme for TESLA/ILC-type Cavities

    SciTech Connect (OSTI)

    J.K. Sekutowicz, P. Kneisel

    2010-05-01T23:59:59.000Z

    This paper reports about our efforts to develop a flangeable coaxial coupler for both HOM and fundamental coupling for 9-cell TESLA/ILC-type cavities. The cavities were designed in early 90‘s for pulsed operation with a low duty factor, less than 1 %. The proposed design of the coupler has been done in a way, that the magnetic flux B at the flange connection is minimized and only a field of <5 mT would be present at the accelerating field Eacc of ~ 36 MV/m (B =150 mT in the cavity). Even though we achieved reasonably high Q-values at low field, the cavity/coupler combination was limited in the cw mode to only ~ 7 MV/m, where a thermally initiated degradation occurred. We have improved the cooling conditions by initially drilling radial channels every 30 degrees, then every 15 degrees into the shorting plate. The modified prototype performed well up to 9 MV/m in cw mode. This paper reports about our experiences with the further modified coaxial coupler and about test results in cw and low duty cycle pulsed mode, similar to the TESLA/ILC operation conditions.

  10. A Vernier Regulator for ILC Marx Droop Compensation

    SciTech Connect (OSTI)

    Tang, Tao

    2009-10-30T23:59:59.000Z

    A two-part compensation scheme, Vernier Regulation, has been applied to offset the voltage droop (40% without correction) in a Marx-topology klystron modulator developed for the International Linear Collider (ILC). Coarse regulation, {+-}5%, is achieved by turning on additional Main Marx cells (Delayed Cells) sequentially as the droop reaches the cell voltage (11 kV). Further regulation to {+-}0.5% is achieved by adding a small Marx in series with the Main Marx. This Vernier Marx is composed of sixteen, 1.2 kV cells that are assembled as a seventeenth cell in the Main Marx. These Vernier Cells are turned on sequentially to generate a series of discrete corrections to the droop in the Main Marx cells with a step size {le}1% of the output voltage. As the required correction reaches 11 kV, all Vernier Cells are turned off synchronously with the turn on of a Delayed Cell. There are up to five Delayed Cells and six Vernier Marx cycles during each ILC Marx output pulse. The Vernier Marx has a local control system that will detect and respond to over-voltage and over-current errors. In this paper, a detailed description of the design, implementation and testing of the Vernier Marx is presented.

  11. Laser Created Relativistic Positron Jets

    SciTech Connect (OSTI)

    Chen, H; Wilks, S C; Meyerhofer, D D; Bonlie, J; Chen, C D; Chen, S N; Courtois, C; Elberson, L; Gregori, G; Kruer, W; Landoas, O; Mithen, J; Murphy, C; Nilson, P; Price, D; Scheider, M; Shepherd, R; Stoeckl, C; Tabak, M; Tommasini, R; Beiersdorder, P

    2009-10-08T23:59:59.000Z

    Electron-positron jets with MeV temperature are thought to be present in a wide variety of astrophysical phenomena such as active galaxies, quasars, gamma ray bursts and black holes. They have now been created in the laboratory in a controlled fashion by irradiating a gold target with an intense picosecond duration laser pulse. About 10{sup 11} MeV positrons are emitted from the rear surface of the target in a 15 to 22-degree cone for a duration comparable to the laser pulse. These positron jets are quasi-monoenergetic (E/{delta}E {approx} 5) with peak energies controllable from 3-19 MeV. They have temperatures from 1-4 MeV in the beam frame in both the longitudinal and transverse directions. Positron production has been studied extensively in recent decades at low energies (sub-MeV) in areas related to surface science, positron emission tomography, basic antimatter science such as antihydrogen experiments, Bose-Einstein condensed positronium, and basic plasma physics. However, the experimental tools to produce very high temperature positrons and high-flux positron jets needed to simulate astrophysical positron conditions have so far been absent. The MeV temperature jets of positrons and electrons produced in our experiments offer a first step to evaluate the physics models used to explain some of the most energetic phenomena in the universe.

  12. Positron Emission Tomography (PET)

    DOE R&D Accomplishments [OSTI]

    Welch, M. J.

    1990-01-00T23:59:59.000Z

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

  13. Studies of positron identification with the

    E-Print Network [OSTI]

    Haviland, David

    Studies of positron identification with the PAMELA calorimeter LAURA ROSSETTO Licentiate Thesis Stockholm, Sweden 2010 #12;#12;Licentiate Thesis Studies of positron identification with the PAMELA

  14. Portable Positron Measurement System (PPMS)

    SciTech Connect (OSTI)

    None

    2011-01-01T23:59:59.000Z

    Portable Positron Measurement System (PPMS) is an automated, non-destructive inspection system based on positron annihilation, which characterizes a material's in situatomic-level properties during the manufacturing processes of formation, solidification, and heat treatment. Simultaneous manufacturing and quality monitoring now are possible. Learn more about the lab's project on our facebook site http://www.facebook.com/idahonationallaboratory.

  15. Portable Positron Measurement System (PPMS)

    ScienceCinema (OSTI)

    None

    2013-05-28T23:59:59.000Z

    Portable Positron Measurement System (PPMS) is an automated, non-destructive inspection system based on positron annihilation, which characterizes a material's in situatomic-level properties during the manufacturing processes of formation, solidification, and heat treatment. Simultaneous manufacturing and quality monitoring now are possible. Learn more about the lab's project on our facebook site http://www.facebook.com/idahonationallaboratory.

  16. Introduction to Positron Emission Tomography

    E-Print Network [OSTI]

    Wisconsin at Madison, University of

    neighboring atom Positron range: 1-10 mm Gamma-Ray range: 10 mm - 8 positron annihilation #2 #1 T Concentration of Radioactivity 1) Gamma-rays escape from body: External detection possible. 2) Two gamma rays Normalized Attenuation- corrected X X X X X X X X X #12;Calibration Converting "counts/pixel" to "micro

  17. Configuration Studies and Recommendations for the ILC DampingRings

    SciTech Connect (OSTI)

    Wolski, Andrzej; Gao, Jie; Guiducci, Susanna

    2006-02-04T23:59:59.000Z

    We describe the results of studies comparing different options for the baseline configuration of the ILC damping rings. The principal configuration decisions apply to the circumference, beam energy, lattice type, and technology options for key components, including the injection/extraction kickers and the damping wigglers. To arrive at our recommended configuration, we performed detailed studies of a range of lattices representing a variety of different configuration options; these lattices are described in Chapter 2. The results of the various studies are reported in chapters covering issues of beam dynamics, technical subsystems, costs, and commissioning, reliability and upgrade ability. Our detailed recommendations for the baseline configuration are given in Chapter 7, where we also outline further research and development that is needed before a machine using our recommended configuration can be built and operated successfully. In the same chapter, we suggest possible alternatives to the baseline configuration.

  18. Interim report on the Global Design Effort Global International Linear Collider (ILC) R&D

    SciTech Connect (OSTI)

    Harrison, M.

    2011-04-30T23:59:59.000Z

    The International Linear Collider: A Technical Progress Report marks the halfway point towards the Global Design Effort fulfilling its mandate to follow up the ILC Reference Design Report with a more optimised Technical Design Report (TDR) by the end of 2012. The TDR will be based on much of the work reported here and will contain all the elements needed to propose the ILC to collaborating governments, including a technical design and implementation plan that are realistic and have been better optimised for performance, cost and risk. We are on track to develop detailed plans for the ILC, such that once results from the Large Hadron Collider (LHC) at CERN establish the main science goals and parameters of the next machine, we will be in good position to make a strong proposal for this new major global project in particle physics. The two overriding issues for the ILC R&D programme are to demonstrate that the technical requirements for the accelerator are achievable with practical technologies, and that the ambitious physics goals can be addressed by realistic ILC detectors. This GDE interim report documents the impressive progress on the accelerator technologies that can make the ILC a reality. It highlights results of the technological demonstrations that are giving the community increased confidence that we will be ready to proceed with an ILC project following the TDR. The companion detector and physics report document likewise demonstrates how detector designs can meet the ambitious and detailed physics goals set out by the ILC Steering Committee. LHC results will likely affect the requirements for the machine design and the detectors, and we are monitoring that very closely, intending to adapt our design as those results become available.

  19. Production And Characterization Of Tungsten-Based Positron Moderators

    SciTech Connect (OSTI)

    Lucio, O. G. de; Morales, J. G.; Cruz-Manjarrez, H. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364 01000, Mexico DF (Mexico)

    2011-06-01T23:59:59.000Z

    Experiments of interest in Atomic Physics require production of well-defined low-energy positron beams through a moderation process of high-energy positrons, which can be produced by either the use of a radioactive source or by accelerator based pair production process. Tungsten is one of the most commonly used moderator materials because of its reasonable efficiency, high work function and relatively low cost. In this work we present different methods to produce tungsten-based candidate moderators in a variety of shapes. We also present results from characterizing these candidate moderators by ion beam analysis and microscopy techniques.

  20. Optimization of the Low Loss SRF Cavity for the ILC

    SciTech Connect (OSTI)

    Sekutowicz, J.S.; /DESY; Kneisel, P.; /Jefferson Lab; Higo, T.; Morozumi, Y.; Saito, K.; /KEK, Tsukuba; Ge, L.; Ko, Yong-kyu; Lee, L.; Li, Z.; Ng, C.K.; Schussman, G.L.; Xiao, L.; /SLAC

    2008-01-18T23:59:59.000Z

    The Low-Loss shape cavity design has been proposed as a possible alternative to the baseline TESLA cavity design for the ILC main linacs. The advantages of this design over the TESLA cavity are its lower cryogenic loss, and higher achievable gradient due to lower surface fields. High gradient prototypes for such designs have been tested at KEK (ICHIRO) and TJNAF (LL). However, issues related to HOM damping and multipacting still need to be addressed. Preliminary numerical studies of the prototype cavities have shown unacceptable damping factors for some higher-order dipole modes if the typical TESLA HOM couplers are directly adapted to the design. The resulting wakefield will dilute the beam emittance thus reducing the machine luminosity. Furthermore, high gradient tests on a 9-cell prototype at KEK have experienced multipacting barriers although a single LL cell had achieved a high gradient. From simulations, multipacting activities are found to occur in the end-groups of the cavity. In this paper, we will present the optimization results of the end-groups for the Low-Loss designs for effective HOM damping and alleviation of multipacting.

  1. Cryogenic infrastructure for Fermilab's ILC vertical cavity test facility

    SciTech Connect (OSTI)

    Carcagno, R.; Ginsburg, C.; Huang, Y.; Norris, B.; Ozelis, J.; Peterson, T.; Poloubotko, V.; Rabehl, R.; Sylvester, C.; Wong, M.; /Fermilab

    2006-06-01T23:59:59.000Z

    Fermilab is building a Vertical Cavity Test Facility (VCTF) to provide for R&D and pre-production testing of bare 9-cell, 1.3-GHz superconducting RF (SRF) cavities for the International Linear Collider (ILC) program. This facility is located in the existing Industrial Building 1 (IB1) where the Magnet Test Facility (MTF) also resides. Helium and nitrogen cryogenics are shared between the VCTF and MTF including the existing 1500-W at 4.5-K helium refrigerator with vacuum pumping for super-fluid operation (125-W capacity at 2-K). The VCTF is being constructed in multiple phases. The first phase is scheduled for completion in mid 2007, and includes modifications to the IB1 cryogenic infrastructure to allow helium cooling to be directed to either the VCTF or MTF as scheduling demands require. At this stage, the VCTF consists of one Vertical Test Stand (VTS) cryostat for the testing of one cavity in a 2-K helium bath. Planning is underway to provide a total of three Vertical Test Stands at VCTF, each capable of accommodating two cavities. Cryogenic infrastructure improvements necessary to support these additional VCTF test stands include a dedicated ambient temperature vacuum pump, a new helium purification skid, and the addition of helium gas storage. This paper describes the system design and initial cryogenic operation results for the first VCTF phase, and outlines future cryogenic infrastructure upgrade plans for expanding to three Vertical Test Stands.

  2. Progress towards crab cavity solutions for the ILC

    SciTech Connect (OSTI)

    Burt, G.; Dexter, A.; /Lancaster U.; Bellantoni, L.; /Fermilab; Beard, C.; Goudket, P.; /Cockcroft Inst. Accel. Sci. Tech.

    2006-06-01T23:59:59.000Z

    In order to achieve acceptable luminosity for ILC crossing angles greater than 2 mrad, RF deflection cavities must be used to rotate electron and position bunches leading up to the IP. A bunch that passes through a deflection cavity at a phase where the deflection averages to zero, receives a crab kick leading to a finite rotation at the IP. For a beam energy of 500 GeV and a crossing angle of 20 mrad the required crab kick is about 11.4 MV at 1.3 GHz and 3.8 MV at 3.9 GHz. Cavities are needed on both beams and are likely to be positioned about 12 m before the IP. Any RF phase error between the bunch and the cavity leads to a deflection of the bunch in addition to a rotation of the bunch. Any differential phase error between the cavities leads to differing deflections and consequential loss in luminosity. An updated analysis of system requirements and phase tolerances with respect to original calculations [1] is given. Issues on cavity and frequency choice are discussed.

  3. EUROTeV-Memo-2007-003 Power loss estimation in the Electrostatic Separators of the ILC

    E-Print Network [OSTI]

    Boyer, Edmond

    EUROTeV-Memo-2007-003 - 1 - Power loss estimation in the Electrostatic Separators of the ILC presents the power loss estimation in the Electrostatic Separators of the ILC alternative head-on scheme-003 - 2 - Computation The computation of the power losses has been realized using DIMAD software

  4. High-intensity positron microprobe at Jefferson Lab

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Golge, Serkan [North Carolina Central Univ., Durham, NC (United States); Vlahovic, Branislav [North Carolina Central Univ., Durham, NC (United States); Wojtsekhowski, Bogdan B. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2014-06-21T23:59:59.000Z

    We present a conceptual design for a novel continuous wave electron-linac based high-intensity slow-positron production source with a projected intensity on the order of 1010 e+/s. Reaching this intensity in our design relies on the transport of positrons (T+ below 600 keV) from the electron-positron pair production converter target to a low-radiation and low-temperature area for moderation in a high-efficiency cryogenic rare gas moderator, solid Ne. The performance of the integrated beamline has been verified through computational studies. The computational results include Monte Carlo calculations of the optimized electron/positron beam energies, converter target thickness, synchronized raster system, transport of the beam from the converter target to the moderator, extraction of the beam from the channel, and moderation efficiency calculations. For the extraction of positrons from the magnetic channel a magnetic field terminator plug prototype has been built and experimental data on the effectiveness of this prototype are presented. The dissipation of the heat away from the converter target and radiation protection measures are also discussed.

  5. High-intensity positron microprobe at Jefferson Lab

    SciTech Connect (OSTI)

    Golge, Serkan [North Carolina Central Univ., Durham, NC (United States); Vlahovic, Branislav [North Carolina Central Univ., Durham, NC (United States); Wojtsekhowski, Bogdan B. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2014-06-21T23:59:59.000Z

    We present a conceptual design for a novel continuous wave electron-linac based high-intensity slow-positron production source with a projected intensity on the order of 1010 e+/s. Reaching this intensity in our design relies on the transport of positrons (T+ below 600 keV) from the electron-positron pair production converter target to a low-radiation and low-temperature area for moderation in a high-efficiency cryogenic rare gas moderator, solid Ne. The performance of the integrated beamline has been verified through computational studies. The computational results include Monte Carlo calculations of the optimized electron/positron beam energies, converter target thickness, synchronized raster system, transport of the beam from the converter target to the moderator, extraction of the beam from the channel, and moderation efficiency calculations. For the extraction of positrons from the magnetic channel a magnetic field terminator plug prototype has been built and experimental data on the effectiveness of this prototype are presented. The dissipation of the heat away from the converter target and radiation protection measures are also discussed.

  6. High-intensity positron microprobe at Jefferson Lab

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Golge, Serkan; Vlahovic, Branislav; Wojtsekhowski, Bogdan B.

    2014-06-21T23:59:59.000Z

    We present a conceptual design for a novel continuous wave electron-linac based high-intensity slow-positron production source with a projected intensity on the order of 1010 e+/s. Reaching this intensity in our design relies on the transport of positrons (T+ below 600 keV) from the electron-positron pair production converter target to a low-radiation and low-temperature area for moderation in a high-efficiency cryogenic rare gas moderator, solid Ne. The performance of the integrated beamline has been verified through computational studies. The computational results include Monte Carlo calculations of the optimized electron/positron beam energies, converter target thickness, synchronized raster system, transport of themore »beam from the converter target to the moderator, extraction of the beam from the channel, and moderation efficiency calculations. For the extraction of positrons from the magnetic channel a magnetic field terminator plug prototype has been built and experimental data on the effectiveness of this prototype are presented. The dissipation of the heat away from the converter target and radiation protection measures are also discussed.« less

  7. Towards a PEBB-Based Design Approach for a Marx-Topology ILC Klystron Modulator

    SciTech Connect (OSTI)

    Macken, K

    2009-10-17T23:59:59.000Z

    Introduced by the U.S. Navy more than a decade ago, the concept of Power Electronic Building Blocks (PEBBs) has been successfully applied in various applications. It is well accepted within the power electronics arena that this concept offers the potential to achieve increased levels of modularity and compactness. This approach is thus ideally suited for applications where easy serviceability and high availability are key, such as the ILC. This paper presents a building block approach for designing a Marx-topology ILC klystron modulator.

  8. Analysis of DESY-Flash LLRF Measurements for the ILC Heavy Beam Loading Test

    SciTech Connect (OSTI)

    Cancelo, Gustavo; Chase, Brian; Davidsaver, Michael; /Fermilab; Carwardine, J.; /Argonne; Simrock, Stefan; Ayvazyan, Valeri; Grecki, Mariusz; /DESY; Matsumoto, Toshihiro; Michizono, Shinichiro; /KEK, Tsukuba

    2009-06-01T23:59:59.000Z

    In September 2008 the DESY-FLASH accelerator was run with up to 550, 3 nano-coulomb bunches at 5 Hz repetition rate. This test is part of a longer-term study aimed at validating ILC parameters by operation as close as possible to ILC beam currents and RF gradients. The present paper reports on the analysis that has been done in order to understand the RF control system performance during this test. Actual klystron power requirements and beam stability are evaluated with heavy beam loading conditions. Results include suggested improvements for upcoming tests in 2009.

  9. Positron emitter labeled enzyme inhibitors

    DOE Patents [OSTI]

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

    1987-05-22T23:59:59.000Z

    This invention involved a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide in activators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

  10. Positron emitter labeled enzyme inhibitors

    DOE Patents [OSTI]

    Fowler, Joanna S. (Bellport, NY); MacGregor, Robert R. (Sag Harbor, NY); Wolf, Alfred P. (Setauket, NY); Langstrom, Bengt (Upsala, SE)

    1990-01-01T23:59:59.000Z

    This invention involves a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography.

  11. SOURCE?

    Energy Savers [EERE]

    Department of Energy (DOE) in partnership with Lawrence Berkeley National Laboratory (LBNL), is an open-source code package designed to be a common, low-cost, standardized tool...

  12. A new way of using positron-lifetime measurements to study lattice defects

    E-Print Network [OSTI]

    Boyer, Edmond

    designed [11]-[13]. In this so-called sealed-source technique, the source material ( N 10 uCi of carrier the vapour pressure of the source material [11], [14]. A technique using metal specimens containing positron ther- mally generated vacancies in metals are conven- tionally analysed by a trapping model which

  13. ISIS2: Pixel Sensor with Local Charge Storage for ILC Vertex Detector

    E-Print Network [OSTI]

    Yiming Li; Chris Damerell; Rui Gao; Rhorry Gauld; Jaya John John; Peter Murray; Andrei Nomerotski; Konstantin Stefanov; Steve Thomas; Helena Wilding; Zhige Zhang

    2010-07-14T23:59:59.000Z

    ISIS (In-situ Storage Imaging Sensor) is a novel CMOS sensor with multiple charge storage capability developed for the ILC vertex detector by the Linear Collider Flavour Identification (LCFI) collaboration. This paper reports test results for ISIS2, the second generation of ISIS sensors implemented in a 0.18 micron CMOS process. The local charge storage and charge transfer were unambiguously demonstrated.

  14. The “accumulation effect” of positrons in the stack of foils, detected by measurements of the positron implantation profile

    SciTech Connect (OSTI)

    Dryzek, Jerzy [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland); Institute of Physics, Opole University, ul. Oleska 48, 45-052 Opole (Poland); Siemek, Krzysztof [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland)

    2013-12-14T23:59:59.000Z

    The profiles of positrons implanted from the radioactive source {sup 22}Na into a stack of foils and plates are the subject of our experimental and theoretical studies. The measurements were performed using the depth scanning of positron implantation profile method, and the theoretical calculations using the phenomenological multi-scattering model (MSM). Several stacks consisting of silver, gold and aluminum foils, and titanium and germanium plates were investigated. We notice that the MSM describes well the experimental profiles; however when the stack consisting of silver and gold foils, the backscattering and linear absorption coefficients differ significantly from those reported in the literature. We suggest the energy dependency of the backscattering coefficient for silver and gold. In the stacks which comprise titanium and germanium plates, there were observed the features, which indicate the presence of the “accumulation effect” in the experimental implantation profile. This effect was previously detected in implantation profiles in Monte Carlo simulations using the GEANT4 tool kit, and it consists in higher localization of positrons close the interface. We suppose that this effect can be essential for positron annihilation in any heterogeneous materials.

  15. High resolution Cerenkov light imaging of induced positron distribution in proton therapy

    SciTech Connect (OSTI)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Fujii, Kento; Morishita, Yuki; Okumura, Satoshi; Komori, Masataka [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Aichi 461-8673 (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, Aichi 462-8508 (Japan)

    2014-11-01T23:59:59.000Z

    Purpose: In proton therapy, imaging of the positron distribution produced by fragmentation during or soon after proton irradiation is a useful method to monitor the proton range. Although positron emission tomography (PET) is typically used for this imaging, its spatial resolution is limited. Cerenkov light imaging is a new molecular imaging technology that detects the visible photons that are produced from high-speed electrons using a high sensitivity optical camera. Because its inherent spatial resolution is much higher than PET, the authors can measure more precise information of the proton-induced positron distribution with Cerenkov light imaging technology. For this purpose, they conducted Cerenkov light imaging of induced positron distribution in proton therapy. Methods: First, the authors evaluated the spatial resolution of our Cerenkov light imaging system with a {sup 22}Na point source for the actual imaging setup. Then the transparent acrylic phantoms (100 × 100 × 100 mm{sup 3}) were irradiated with two different proton energies using a spot scanning proton therapy system. Cerenkov light imaging of each phantom was conducted using a high sensitivity electron multiplied charge coupled device (EM-CCD) camera. Results: The Cerenkov light’s spatial resolution for the setup was 0.76 ± 0.6 mm FWHM. They obtained high resolution Cerenkov light images of the positron distributions in the phantoms for two different proton energies and made fused images of the reference images and the Cerenkov light images. The depths of the positron distribution in the phantoms from the Cerenkov light images were almost identical to the simulation results. The decay curves derived from the region-of-interests (ROIs) set on the Cerenkov light images revealed that Cerenkov light images can be used for estimating the half-life of the radionuclide components of positrons. Conclusions: High resolution Cerenkov light imaging of proton-induced positron distribution was possible. The authors conclude that Cerenkov light imaging of proton-induced positron is promising for proton therapy.

  16. High-field penning-malmberg trap: confinement properties and use in positron accumulation

    SciTech Connect (OSTI)

    Hartley, J.H.

    1997-09-01T23:59:59.000Z

    This dissertation reports on the development of the 60 kG cryogenic positron trap at Lawrence Livermore National Laboratory, and compares the trap`s confinement properties with other nonneutral plasma devices. The device is designed for the accumulation of up to 2{times}10{sup 9} positrons from a linear-accelerator source. This positron plasma could then be used in Bhabha scattering experiments. Initial efforts at time-of-flight accumulation of positrons from the accelerator show rapid ({approximately}100 ms) deconfinement, inconsistent with the long electron lifetimes. Several possible deconfinement mechanisms have been explored, including annihilation on residual gas, injection heating, rf noise from the accelerator, magnet field curvature, and stray fields. Detailed studies of electron confinement demonstrate that the empirical scaling law used to design the trap cannot be extrapolated into the parameter regime of this device. Several possible methods for overcoming these limitations are presented.

  17. A Benchmark Construction of Positron Crystal Undulator

    E-Print Network [OSTI]

    Tikhomirov, Victor V

    2015-01-01T23:59:59.000Z

    Optimization of a positron crystal undulator (CU) is addressed. The ways to assure both the maximum intensity and minimum spectral width of positron CU radiation are outlined. We claim that the minimum CU spectrum width of 3 -- 4% is reached at the positron energies of a few GeV and that the optimal bending radius of crystals planes in CU ranges from 3 to 5 critical bending radii for channeled particles. Following suggested approach a benchmark positron CU construction is devised and its functioning is illustrated using the simulation method widely tested by experimental data.

  18. The ILC P2 Marx and Application of the Marx Topology to Future Accelerators

    SciTech Connect (OSTI)

    Kemp, M.A.; Benwell, A.; Burkhart, C.; Hugyik, J.; Larsen, R.; Macken, K.; MacNair, D.; Nguyen, M.; Olsen, J.; /SLAC

    2011-08-19T23:59:59.000Z

    The SLAC P2 Marx is under development as the linac klystron modulator for the ILC. This modulator builds upon the success of the P1 Marx, which is currently undergoing lifetime evaluation. While the SLAC P2 Marx's (henceforth, 'P2 Marx') target application is the ILC, characteristics of the Marx topology make it equally well-suited for operation at different parameter ranges; for example, increased pulse repetition frequency, increased output current, longer pulse width, etc. Marx parameters such as the number of cells, cell capacitance, and component selection can be optimized for the application. This paper provides an overview of the P2 Marx development. In addition, the scalability of the Marx topology to other long-pulse parameter ranges is discussed.

  19. The study of the photon structure function at the ILC energy range

    E-Print Network [OSTI]

    Krupa, B; Zawiejski, L

    2015-01-01T23:59:59.000Z

    At the future $e^{+}e^{-}$ linear collider ILC/CLIC it will be able to measure the photon structure functions in a wider range of kinematic variables x and $Q^{2}$ in comparison to the previous results of experiments at LEP. The classical way to measure the photon structure functions is the study of $e^{+}e^{-} \\rightarrow e^{+}e^{-} {\\gamma}{\\gamma} \\rightarrow e^{+}e^{-}$ X process, where X is the leptonic or hadronic final state. For the study of the QED and hadronic photon structure functions the simulations of two-photon processes were performed at the ILC center-of-mass energy equal to 500 GeV using the PYTHIA and the ILCSoft package. The analysis used information related to the forward detectors, tracking detectors and calorimeters which are parts of the ILD detector concept.

  20. Electron and positron pair production of compact stars

    E-Print Network [OSTI]

    Wen-Biao Han; Remo Ruffini; She-Sheng Xue

    2012-09-15T23:59:59.000Z

    Neutral stellar core at or over nuclear densities is described by a positive charged baryon core and negative charged electron fluid since they possess different masses and interactions. Based on a simplified model of a gravitationally collapsing or pulsating baryon core, we approximately integrate the Einstein-Maxwell equations and the equations for the number and energy-momentum conservation of complete degenerate electron fluid. We show possible electric processes that lead to the production of electron-positron pairs in the boundary of a baryon core and calculate the number and energy of electron-positron pairs. This can be relevant for understanding the energetic sources of supernovae and gamma-ray bursts.

  1. Development of positron annihilation spectroscopy for characterizing neutron irradiated tungsten

    SciTech Connect (OSTI)

    C.N. Taylor; M. Shimada; D.W. Akers; M.W. Drigert; B.J. Merrill; Y. Hatano

    2013-05-01T23:59:59.000Z

    Tungsten samples (6 mm diameter, 0.2 mm thick) were irradiated to 0.025 and 0.3 dpa with neutrons in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Samples were then exposed to deuterium plasma in the tritium plasma experiment (TPE) at 100, 200 and 500ºC to a total fluence of 1 x 1026 m-2. Nuclear reaction analysis (NRA) and Doppler broadening positron annihilation spectroscopy (DB-PAS) were performed at various stages to characterize damage and retention. We present the first known results of neutron damaged tungsten characterized by DB-PAS in order to study defect concentration. Two positron sources, 22Na and 68Ge, probe ~58 µm and through the entire 200 µm thick samples, respectively. DB-PAS results reveal clear differences between the various irradiated samples. These results, and the calibration of DB-PAS to NRA data are presented.

  2. EMISSION AND TRANSMISSION NOISE PROPAGATION IN POSITRON EMISSION COMPUTED TOMOGRAPHY

    E-Print Network [OSTI]

    Gullberg, G.T.

    2010-01-01T23:59:59.000Z

    High Resolution Computed Tomography of Positron Emitters,"of Dynamic Emission Computed Tomography," J. Nucl. Med. ~:IN POSITRON EMISSION COMPUTED TOMOGRAPHY RECEIVED lAWRENCE

  3. Positron emission tomography wrist detector

    DOE Patents [OSTI]

    Schlyer, David J. (Bellport, NY); O'Connor, Paul (Bellport, NY); Woody, Craig (Setauket, NY); Junnarkar, Sachin Shrirang (Sound Beach, NY); Radeka, Veljko (Bellport, NY); Vaska, Paul (Sound Beach, NY); Pratte, Jean-Francois (Stony Brook, NY)

    2006-08-15T23:59:59.000Z

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal representing a time-of-occurrence of an annihilation event, generating an address signal representing a channel detecting the annihilation event, and generating a channel signal including the time and address signals. The method also includes generating a composite signal including the channel signal and another similarly generated channel signal concerning another annihilation event. An apparatus that serially transfers annihilation information includes a time signal generator, address signal generator, channel signal generator, and composite signal generator. The time signal is asynchronous and the address signal is synchronous to a clock signal. A PET scanner includes a scintillation array, detection array, front-end array, and a serial encoder. The serial encoders include the time signal generator, address signal generator, channel signal generator, and composite signal generator.

  4. The positron density in the intergalactic medium and the galactic 511 keV line

    E-Print Network [OSTI]

    Vecchio, A; Miralda-Escude, J; Pena-Garay, C

    2013-01-01T23:59:59.000Z

    The 511 keV electron-positron annihilation line, most recently characterized by the INTEGRAL/SPI experiment, is highly concentrated towards the Galactic centre. Its origin remains unknown despite decades of scrutiny. We propose a novel scenario in which known extragalactic positron sources such as radio jets of active galactic nuclei (AGN) fill the intergalactic medium with MeV e+e- pairs, which are then accreted into the Milky Way. We show that interpreting the diffuse cosmic radio background (CRB) as arising from radio sources with characteristics similar to the observed cores and radio lobes in powerful AGN jets suggests that the intergalactic positron-to-electron ratio could be as high as 10^{-5}, although this can be decreased if the CRB is not all produced by pairs and if not all positrons escape to the intergalactic medium. Assuming an accretion rate of one solar mass per year of matter into the Milky Way, a positron-to-electron ratio of only 10^{-7} is already enough to account for much of the 511 keV...

  5. The positron density in the intergalactic medium and the galactic 511 keV line

    E-Print Network [OSTI]

    A. Vecchio; A. C. Vincent; J. Miralda-Escude; C. Pena-Garay

    2013-04-01T23:59:59.000Z

    The 511 keV electron-positron annihilation line, most recently characterized by the INTEGRAL/SPI experiment, is highly concentrated towards the Galactic centre. Its origin remains unknown despite decades of scrutiny. We propose a novel scenario in which known extragalactic positron sources such as radio jets of active galactic nuclei (AGN) fill the intergalactic medium with MeV e+e- pairs, which are then accreted into the Milky Way. We show that interpreting the diffuse cosmic radio background (CRB) as arising from radio sources with characteristics similar to the observed cores and radio lobes in powerful AGN jets suggests that the intergalactic positron-to-electron ratio could be as high as 10^{-5}, although this can be decreased if the CRB is not all produced by pairs and if not all positrons escape to the intergalactic medium. Assuming an accretion rate of one solar mass per year of matter into the Milky Way, a positron-to-electron ratio of only 10^{-7} is already enough to account for much of the 511 keV emission of the Galaxy. A simple spherical accretion model predicts an emission profile highly peaked in the central bulge, consistent with INTEGRAL observations. However, a realistic model of accretion with angular momentum would likely imply a more extended emission over the disk, with uncertainties depending on the magnetic field structure and turbulence in the galactic halo.

  6. Study of electron-positron interactions

    SciTech Connect (OSTI)

    Abashian, A.; Gotow, K.; Philonen, L.

    1990-09-15T23:59:59.000Z

    For the past seven years, this group has been interested in the study of tests of the Standard Model of Electroweak interactions. The program has centered about the AMY experiment which examines the nature of the final state products in electron-positron collisions in the center of mass energy range near 60 GeV. Results of these measurements have shown a remarkable consistency with the predictions of the minimal model of 3 quark and lepton generations and single charged and neutral intermediate bosons. No new particles or excited states have been observed nor has any evidence for departures in cross sections or angular asymmetries from expectations been observed. These conclusions have been even more firmly established by the higher energy results from the LEP and SLC colliders at center of mass energies of about 90 GeV. Our focus is shifting to the neutrino as a probe to electroweak interactions. The relative merit of attempting to observe neutrinos from point sources versus observing neutrinos generally is not easy to predict. The improved ability to interpret is offset by the probably episodic nature of the emission and irreproducibility of the results. In this phase of development, it is best to be sensitive to both sources of neutrinos. As a second phase of our program at Virginia Tech, we are studying the feasibility of detecting cosmic ray neutrinos in a proposed experiment which we have called NOVA. the results of the test setup will be instrumental in developing an optimum design. A third program we are involved in is the MEGA experiment at Los Alamos, an experiment to place a limit on the rate of muon decay to electron plus photon which is forbidden by the Standard Model.

  7. The ILC Energy Requirements from the Constraints on New Boson Production at the Tevatron

    E-Print Network [OSTI]

    Mihail V. Chizhov

    2007-09-15T23:59:59.000Z

    Direct constraints on the masses of new heavy bosons by the Tevatron data are discussed. Some excesses in the experimental data are interpreted as a resonance production of new charged and `leptophobic' neutral chiral bosons with masses around 500 GeV and 700 GeV, respectively. The interpretation was provided on the basis of the theoretical model, proposed by the author about 15 years ago. New Tevatron data and the LHC results will definitely confirm or reject this interpretation. The ILC with an energy above 1 TeV would be an ideal place to produce and to study the properties of these particles.

  8. Magnet reliability in the Fermilab Main Injector and implications for the ILC

    SciTech Connect (OSTI)

    Tartaglia, M.A.; Blowers, J.; Capista, D.; Harding, D.J.; Kiemschies, O.; Rahimzadeh-Kalaleh, S.; Tompkins, J.C.; /Fermilab

    2007-08-01T23:59:59.000Z

    The International Linear Collider reference design requires over 13000 magnets, of approximately 135 styles, which must operate with very high reliability. The Fermilab Main Injector represents a modern machine with many conventional magnet styles, each of significant quantity, that has now accumulated many hundreds of magnet-years of operation. We review here the performance of the magnets built for this machine, assess their reliability and categorize the failure modes, and discuss implications for reliability of similar magnet styles expected to be used at the ILC.

  9. Addiction Studies with Positron Emission Tomography

    ScienceCinema (OSTI)

    Joanna Fowler

    2010-01-08T23:59:59.000Z

    Brookhaven scientist Joanna Fowler describes Positron Emission Technology (PET) research at BNL which for the past 30 years has focused in the integration of basic research in radiotracer chemistry with the tools of neuroscience to develop new scientific

  10. Design Considerations for a PEBB-Based Marx-Topology ILC Klystron Modulator

    SciTech Connect (OSTI)

    Macken, K.; Beukers, T.; Burkhart, C.; Kemp, M.A.; Nguyen, M.N.; Tang, T.; /SLAC

    2009-12-09T23:59:59.000Z

    The concept of Power Electronic Building Blocks (PEBBs) has its origin in the U.S. Navy during the last decade of the past century. As compared to a more conventional or classical design approach, a PEBB-oriented design approach combines various potential advantages such as increased modularity, high availability and simplified serviceability. This relatively new design paradigm for power conversion has progressively matured since then and its underlying philosophy has been clearly and successfully demonstrated in a number of real-world applications. Therefore, this approach has been adopted here to design a Marx-topology modulator for an International Linear Collider (ILC) environment where easy serviceability and high availability are crucial. This paper describes various aspects relating to the design of a 32-cell Marx-topology ILC klystron modulator. The concept of nested droop correction is introduced and illustrated. Several design considerations including cosmic ray withstand, power cycling capability, fault tolerance, etc., are discussed. Details of the design of a Marx cell PEBB are included.

  11. A Hierarchical Control Architecture for a PEBB-Based ILC Marx Modulator

    SciTech Connect (OSTI)

    Macken, K.; Burkhart, C.; Larsen, R.; Nguyen, M.N.; Olsen, J.; /SLAC

    2011-12-15T23:59:59.000Z

    The idea of building power conversion systems around Power Electronic Building Blocks (PEBBs) was initiated by the U.S. Office of Naval Research in the mid 1990s. A PEBB-based design approach is advantageous in terms of power density, modularity, reliability, and serviceability. It is obvious that this approach has much appeal for pulsed power conversion including the International Linear Collider (ILC) klystron modulator application. A hierarchical control architecture has the inherent capability to support the integration of PEBBs. This has already been successfully demonstrated in a number of industrial applications in the recent past. This paper outlines the underlying concepts of a hierarchical control architecture for a PEBB-based Marx-topology ILC klystron modulator. The control in PEBB-based power conversion systems can be functionally partitioned into (three) hierarchical layers; system layer, application layer, and PEBB layer. This has been adopted here. Based on such a hierarchical partition, the interfaces are clearly identified and defined and, consequently, are easily characterised. A conceptual design of the hardware manager, executing low-level hardware oriented tasks, is detailed. In addition, the idea of prognostics is briefly discussed.

  12. FINAL DESIGN OF ILC RTML EXTRACTION LINE FOR SINGLE STAGE BUNCH COMPRESSOR

    SciTech Connect (OSTI)

    Seletskiy, S.; Solyak, N.

    2011-03-28T23:59:59.000Z

    The use of single stage bunch compressor (BC) in the International Linear Collider (ILC) Damping Ring to the Main Linac beamline (RTML) requires new design for the extraction line (EL). The EL located downstream of the BC will be used for both an emergency abort dumping of the beam and the tune-up continuous train-by-train extraction. It must accept both compressed and uncompressed beam with energy spread of 3.54% and 0.15% respectively. In this paper we report the final design that allowed minimizing the length of such extraction line while offsetting the beam dumps from the main line by 5m distance required for acceptable radiation level in the service tunnel. Proposed extraction line can accommodate beams with different energy spreads at the same time providing the beam size suitable for the aluminum ball dump window. We described the final design of the ILC RTML extraction line located downstream of the new single-stage bunch compressor. The extraction line is only 24m long and is capable of accepting and transmitting 220kW of beam power. The EL can be used for both fast intra-train and continual extraction, and is capable of accepting both 0.15% and 3.54% energy spread beams at 5MeV and 4.37MeV respectively.

  13. Cold trapped positrons and progress to cold antihydrogen

    E-Print Network [OSTI]

    Estrada, John Karl, 1970-

    2002-01-01T23:59:59.000Z

    A new physical mechanism for positron accumulation is explained and demonstrated. Strongly magnetized Rydberg positronium is formed and then ionized, allowing us to trap equal numbers of either positrons or electrons over ...

  14. Beam Ion Instability in ILC Damping Ring with Multi-Gas Species

    SciTech Connect (OSTI)

    Wang, Lanfa; Pivi, Mauro; /SLAC

    2012-05-30T23:59:59.000Z

    Ion induced beam instability is one critical issue for the electron damping ring of the International Linear Collider (ILC) due to its ultra small emittance of 2 pm. The beam ion instability with various beam filling patterns for the latest lattice DTC02 is studied using PIC code. The code has been benchmarked with SPEAR3 experimental data and there is a good agreement between the simulation and observations. It uses the optics from MAD and can handle arbitrary beam filling pattern and vacuum. Different from previous studies, multi-gas species and exact beam filling patterns have been modeled simultaneously in the study. This feature makes the study more realistic. Analyses have been done to compare with the simulations.

  15. Physics perspectives at JLab with a polarized positron beam

    SciTech Connect (OSTI)

    Voutier, Eric J.-M. [UNIV. JOSEPH FOURNIER, GRENOBLE, France

    2014-06-01T23:59:59.000Z

    Polarized positron beams are in some respect mandatory complements to polarized electron beams. The advent of the PEPPo concept for polarized positron production opens the possibility for the developement at the Jefferson Laboratory of a continuous polarized positron beam. The benefits of such a beam for hadronic structure studies are discussed, together with the technical and technological challenges to face.

  16. Overview of high gradient SRF R&D for ILC cavities at Jefferson Lab

    SciTech Connect (OSTI)

    Geng, Rongli [JLAB

    2009-11-01T23:59:59.000Z

    We report the progress on high gradient R&D of ILC cavities at Jefferson Lab (JLab) since the Beijing workshop. Routine 9-cell cavity electropolishing (EP) processing and RF testing has been enhanced with added surface mapping and T-mapping instrumentations. 12 new 9-cell cavities (10 of them are baseline fine-grain TESLA-shape cavities: 5 built by ACCEL/Research Instruments, 4 by AES and 1 by JLab; 2 of them are alternative cavities: 1 fine-grain ICHIRO-shape cavity built by KEK/Japan industry and 1 large-grain TESLA-shape cavity built by JLab) are EP processed and tested. 76 EP cycles are accumulated, corresponding to more than 200 hours of active EP time. Field emission (FE) and quench behaviors of electropolished 9-cell cavities are studied. EP process continues to be optimized, resulting in advanced procedures and hence improved cavity performance. Several 9-cell cavities reached 35 MV/m after the first light EP processing. FE-free performance has been demonstrated in 9-cell cavities in 35-40 MV/m range. 1-cell cavity studies explore new techniques for defect removal as well as advanced integrated cavity processing. Surface studies of niobium samples electropolished together with real cavities provide new insight into the nature of field emitters. Close cooperation with the US cavity fabrication industry has been undertaking with the successful achievement of 41 MV/m for the first time in a 9-cell ILC cavity built by AES. As the size of the data set grows, it is now possible to construct gradient yield curves, from which one can see that significant progress has been made in raising the high gradient yield.

  17. ILC2

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) EnvironmentalGyroSolé(tm)Hydrogen Storage inChangApplications | MIT-Harvard Center

  18. Positron Annihilation in the Bipositronium Ps2

    SciTech Connect (OSTI)

    Bailey, David H.; Frolov, Alexei M.

    2005-07-01T23:59:59.000Z

    The electron-positron-pair annihilation in the bipositronium PS2 is considered. In particular, the two-, three-, one- and zero-photon annihilation rates are determined to high accuracy. The corresponding analytical expressions are also presented. Also, a large number of bound state properties have been determined for this system.

  19. Positron annihilation with core and valence electrons

    E-Print Network [OSTI]

    Green, D G

    2015-01-01T23:59:59.000Z

    $\\gamma$-ray spectra for positron annihilation with the core and valence electrons of the noble gas atoms Ar, Kr and Xe is calculated within the framework of diagrammatic many-body theory. The effect of positron-atom and short-range positron-electron correlations on the annihilation process is examined in detail. Short-range correlations, which are described through non-local corrections to the vertex of the annihilation amplitude, are found to significantly enhance the spectra for annihilation on the core orbitals. For Ar, Kr and Xe, the core contributions to the annihilation rate are found to be 0.55\\%, 1.5\\% and 2.2\\% respectively, their small values reflecting the difficulty for the positron to probe distances close to the nucleus. Importantly however, the core subshells have a broad momentum distribution and markedly contribute to the annihilation spectra at Doppler energy shifts $\\gtrsim3$\\,keV, and even dominate the spectra of Kr and Xe at shifts $\\gtrsim5$\\,keV. Their inclusion brings the theoretical ...

  20. Relativistic Positron Creation Using Ultra-Intense Short Pulse Lasers

    SciTech Connect (OSTI)

    Chen, H; Wilks, S; Bonlie, J; Liang, E; Myatt, J; Price, D; Meyerhofer, D; Beiersdorfer, P

    2008-08-25T23:59:59.000Z

    We measure up to 2 x 10{sup 10} positrons per steradian ejected out the back of {approx}mm thick gold targets when illuminated with short ({approx} 1 ps) ultra-intense ({approx} 1 x 10{sup 20} W/cm{sup 2}) laser pulses. Positrons produced predominately by the Bethe-Heitler process and have an effective temperature of 2-4 MeV, with the distribution peaking at 4-7 MeV. The angular distribution of the positrons is anisotropic. The measurements indicate the laser produced, relativistic positron densities ({approx} 10{sup 16} positrons/cm{sup 3}) are the highest ever created in the laboratory.

  1. High-intensity positron microprobe at the Thomas Jefferson National Accelerator Facility

    SciTech Connect (OSTI)

    Golge, S., E-mail: serkan.golge@nasa.gov; Vlahovic, B. [North Carolina Central University, Durham, North Carolina 27707 (United States); Wojtsekhowski, B. [Jefferson Laboratory, 12000 Jefferson Ave., Newport News, Virginia 23606 (United States)

    2014-06-21T23:59:59.000Z

    We present a conceptual design for a novel continuous wave electron-linac based high-intensity high-brightness slow-positron production source with a projected intensity on the order of 10{sup 10?}e{sup +}/s. Reaching this intensity in our design relies on the transport of positrons (T{sub +} below 600?keV) from the electron-positron pair production converter target to a low-radiation and low-temperature area for moderation in a high-efficiency cryogenic rare gas moderator, solid Ne. This design progressed through Monte Carlo optimizations of: electron/positron beam energies and converter target thickness, transport of the e{sup +} beam from the converter to the moderator, extraction of the e{sup +} beam from the magnetic channel, a synchronized raster system, and moderator efficiency calculations. For the extraction of e{sup +} from the magnetic channel, a magnetic field terminator plug prototype has been built and experimental results on the effectiveness of the prototype are presented. The dissipation of the heat away from the converter target and radiation protection measures are also discussed.

  2. Deconvolution of positron annihilation coincidence Doppler broadening spectra using iterative projected Newton method with non-negativity

    E-Print Network [OSTI]

    Soatto, Stefano

    accumulation rate, suffers from the poor intrinsic resolution of HP(Ge) gamma ray spectroscopy systems of the 514 keV gamma ray line of 85 Sr where photons from the source are observed in pseudo-coincidence [71 Deconvolution of positron annihilation coincidence Doppler broadening spectra using iterative

  3. Positron annihilation study of P implanted Si

    SciTech Connect (OSTI)

    Asoka-Kumar, P.; Au, H.L.; Lynn, K.G. [Brookhaven National Lab., Upton, NY (United States); Sferlazzo, P. [Eaton Corp., Beverly, MA (United States). SED Division

    1992-12-01T23:59:59.000Z

    High-energy ion implantation (above 200 keV) is now commonly used in a variety of VLSI processes. The high energy required for these implants is often achieved by implanting multiply charged ions, which inevitably brings in the problem of low-energy ion contamination. The low-energy contamination is difficult to diagnose and detect. Positron annihilation spectroscopy is used to examine the defect distributions in these high energy implants with varying degrees of contamination.

  4. Can we explain AMS-02 antiproton and positron excesses simultaneously by nearby supernovae without pulsars nor dark matter?

    E-Print Network [OSTI]

    Kohri, Kazunori; Fujita, Yutaka; Yamazaki, Ryo

    2015-01-01T23:59:59.000Z

    We explain the excess of the antiproton fraction recently reported by the AMS-02 experiment by considering collisions between cosmic-ray protons accelerated by a local supernova remnant (SNR) and the surrounding dense cloud. The same "pp collisions" provide the right branching ratio to fit the observed positron excess simultaneously without a fine tuning. The supernova happened in relatively lower metalicity than the major cosmic-ray sources. The cutoff energy of electrons marks the supernova age of ~10^{5} years, while the antiproton excess may extend to higher energy. Both antiproton and positron fluxes are completely consistent with our predictions in Fujita, Kohri, Yamazaki and Ioka (2009).

  5. Optimization of the Low-Loss SRF Cavity for the ILC

    SciTech Connect (OSTI)

    Z. Li; L. Ge; K. Ko; L. Lee; C.-K. Ng; G. L. Schussman; L. Xiao; T. Higo; Y. Morozumi; K. Saito; P. Kneisel; J. S. Sekutowicz

    2007-08-01T23:59:59.000Z

    The Low-Loss shape cavity design has been proposed as a possible alternative to the baseline TESLA cavity design for the ILC. The advantages of this design over the TESLA cavity are its lower cryogenic loss, and higher achievable gradient due to lower surface fields. High gradient prototypes for such designs have been tested at KEK (ICHIRO) and JLab (LL). However, issues related to HOM damping and multipacting (MP) still need to be addressed. Preliminary numerical studies of the prototype cavities have shown unacceptable damping for some higher-order dipole modes if the typical TESLA HOM couplers are directly adapted to the design. The resulting wakefield will dilute the beam emittance thus reduces the machine luminosity. Furthermore, high gradient tests on a 9-cell prototype at KEK have experienced MP barriers although a single LL cell had achieved a high gradient. From simulations, MP activities are found to occur in the end-groups of the cavity. In this paper, we will present the optimization results of the end-groups for the Low-Loss shape for effective HOM damping and alleviation of multipacting. Comparisons of simulation results with measurements will also be presented.

  6. Compact, Intelligent, Digitally Controlled IGBT Gate Drivers for a PEBB-Based ILC Marx Modulator

    SciTech Connect (OSTI)

    Nguyen, M.N.; Burkhart, C.; Olsen, J.J.; Macken, K.; /SLAC; ,

    2010-06-07T23:59:59.000Z

    SLAC National Accelerator Laboratory has built and is currently operating a first generation prototype Marx klystron modulator to meet ILC specifications. Under development is a second generation prototype, aimed at improving overall performance, serviceability, and manufacturability as compared to its predecessor. It is designed around 32 cells, each operating at 3.75 kV and correcting for its own capacitor droop. Due to the uniqueness of this application, high voltage gate drivers needed to be developed for the main 6.5 kV and droop correction 1.7 kV IGBTs. The gate driver provides vital functions such as protection of the IGBT from over-voltage and over-current, detection of gate-emitter open and short circuit conditions, and monitoring of IGBT degradation (based on collector-emitter saturation voltage). Gate drive control, diagnostic processing capabilities, and communication are digitally implemented using an FPGA. This paper details the design of the gate driver circuitry, component selection, and construction layout. In addition, experimental results are included to illustrate the effectiveness of the protection circuit.

  7. International Linear Collider Reference Design Report Volume 2: Physics at the ILC

    SciTech Connect (OSTI)

    Aarons, Gerald; Abe, Toshinori; Abernathy, Jason; Ablikim, Medina; Abramowicz, Halina; Adey, David; Adloff, Catherine; Adolphsen, Chris; Afanaciev, Konstantin; Agapov, Ilya; Ahn, Jung-Keun; Aihara, Hiroaki; Akemoto, Mitsuo; del Carmen Alabau, Maria; Albert, Justin; Albrecht, Hartwig; Albrecht, Michael; Alesini, David; Alexander, Gideon; Alexander, Jim; Allison, Wade; /SLAC /Tokyo U. /Victoria U. /Beijing, Inst. High Energy Phys. /Tel Aviv U. /Birmingham U. /Annecy, LAPP /Minsk, High Energy Phys. Ctr. /DESY /Royal Holloway, U. of London /CERN /Pusan Natl. U. /KEK, Tsukuba /Orsay, LAL /Notre Dame U. /Frascati /Cornell U., Phys. Dept. /Oxford U. /Hefei, CUST /Bangalore, Indian Inst. Sci. /Fermilab

    2011-11-14T23:59:59.000Z

    The triumph of 20th century particle physics was the development of the Standard Model and the confirmation of many of its aspects. Experiments determined the particle constituents of ordinary matter, and identified four forces that hold matter together and transform it from one form to another. Particle interactions were found to obey precise laws of relativity and quantum theory. Remarkable features of quantum physics were observed, including the real effects of 'virtual' particles on the visible world. Building on this success, particle physicists are now able to address questions that are even more fundamental, and explore some of the deepest mysteries in science. The scope of these questions is illustrated by this summary from the report Quantum Universe: (1) Are there undiscovered principles of nature; (2) How can we solve the mystery of dark energy; (3) Are there extra dimensions of space; (4) Do all the forces become one; (5) Why are there so many particles; (6) What is dark matter? How can we make it in the laboratory; (7) What are neutrinos telling us; (8) How did the universe begin; and (9) What happened to the antimatter? A worldwide program of particle physics investigations, using multiple approaches, is already underway to explore this compelling scientific landscape. As emphasized in many scientific studies, the International Linear Collider is expected to play a central role in what is likely to be an era of revolutionary advances. Discoveries from the ILC could have breakthrough impact on many of these fundamental questions. Many of the scientific opportunities for the ILC involve the Higgs particle and related new phenomena at Terascale energies. The Standard Model boldly hypothesizes a new form of Terascale energy, called the Higgs field, that permeates the entire universe. Elementary particles acquire mass by interacting with this field. The Higgs field also breaks a fundamental electroweak force into two forces, the electromagnetic and weak forces, which are observed by experiments in very different forms. So far, there is no direct experimental evidence for a Higgs field or the Higgs particle that should accompany it. Furthermore, quantum effects of the type already observed in experiments should destabilize the Higgs boson of the Standard Model, preventing its operation at Terascale energies. The proposed antidotes for this quantum instability mostly involve dramatic phenomena at the Terascale: new forces, a new principle of nature called supersymmetry, or even extra dimensions of space. Thus for particle physicists the Higgs boson is at the center of a much broader program of discovery, taking off from a long list of questions. Is there really a Higgs boson? If not, what are the mechanisms that give mass to particles and break the electroweak force? If there is a Higgs boson, does it differ from the hypothetical Higgs of the Standard Model? Is there more than one Higgs particle? What are the new phenomena that stabilize the Higgs boson at the Terascale? What properties of Higgs boson inform us about these new phenomena? Another major opportunity for the ILC is to shed light on the dark side of the universe. Astrophysical data shows that dark matter dominates over visible matter, and that almost all of this dark matter cannot be composed of known particles. This data, combined with the concordance model of Big Bang cosmology, suggests that dark matter is comprised of new particles that interact weakly with ordinary matter and have Terascale masses. It is truely remarkable that astrophysics and cosmology, completely independently of the particle physics considerations reviewed above, point to new phenomena at the Terascale. If Terascale dark matter exists, experiments at the ILC should be able to produce such particles in the laboratory and study their properties. Another list of questions will then beckon. Do these new particles really have the correct properties to be the dark matter? Do they account for all of the dark matter, or only part of it? What do their properties tell us about the evolut

  8. Detectors for Linear Colliders: Detector design for a Future Electron-Positron Collider (4/4)

    ScienceCinema (OSTI)

    None

    2011-10-06T23:59:59.000Z

    In this lecture I will discuss the issues related to the overall design and optimization of a detector for ILC and CLIC energies. I will concentrate on the two main detector concepts which are being developed in the context of the ILC. Here there has been much recent progress in developing realistic detector models and in understanding the physics performance of the overall detector concept. In addition, I will discuss the how the differences in the detector requirements for the ILC and CLIC impact the overall detector design.

  9. Advanced Light Source control system

    SciTech Connect (OSTI)

    Magyary, S.; Chin, M.; Cork, C.; Fahmie, M.; Lancaster, H.; Molinari, P.; Ritchie, A.; Robb, A.; Timossi, C.

    1989-03-01T23:59:59.000Z

    The Advanced Light Source (ALS) is a third generation 1--2 GeV synchrotron radiation source designed to provide ports for 60 beamlines. It uses a 50 MeV electron linac and 1.5 GeV, 1 Hz, booster synchrotron for injection into a 1--2 GeV storage ring. Interesting control problems are created because of the need for dynamic closed beam orbit control to eliminate interaction between the ring tuning requirements and to minimize orbit shifts due to ground vibrations. The extremely signal sensitive nature of the experiments requires special attention to the sources of electrical noise. These requirements have led to a control system design which emphasizes connectivity at the accelerator equipment end and a large I/O bandwidth for closed loop system response. Not overlooked are user friendliness, operator response time, modeling, and expert system provisions. Portable consoles are used for local operation of machine equipment. Our solution is a massively parallel system with >120 Mbits/sec I/O bandwidth and >1500 Mips computing power. At the equipment level connections are made using over 600 powerful Intelligent Local Controllers (ILC-s) mounted in 3U size Eurocard slots using fiber-optic cables between rack locations. In the control room, personal computers control and display all machine variables at a 10 Hz rate including the scope signals which are collected though the control system. Commercially available software and industry standards are used extensively. Particular attention is paid to reliability, maintainability and upgradeability. 10 refs., 11 figs.

  10. animal positron emission: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Xenon (LXe) in the scintillation mode is studied for Positron Emission Tomography (PET) of small animals. Its specific design aims at taking full advantage of the Liquid...

  11. analogs potential positron: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and few satellite discrete electronic components used in Positron Emission Tomography (PET). Described approach simplifies electronic circuits, reduces the power consumption,...

  12. What is the fate of runaway positrons in tokamaks?

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Jian [University of Science and Technology of China, Hefei, Anhui (China). Center for Advanced Fusion Energy and Plasma Sciences; Qin, Hong [University of Science and Technology of China, Hefei, Anhui (China). Center for Advanced Fusion Energy and Plasma Sciences; Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Fisch, Nathaniel J. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Teng, Qian [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Wang, Xiaogang [Peking Univ, Beijing (China). School of Physics

    2014-06-01T23:59:59.000Z

    Massive runaway positrons are generated by runaway electrons in tokamaks. The fate of these positrons encodes valuable information about the runaway dynamics. The phase space dynamics of a runaway position is investigated using a Lagrangian that incorporates the tokamak geometry, loop voltage, radiation and collisional effects. It is found numerically that runaway positrons will drift out of the plasma to annihilate on the first wall, with an in-plasma annihilation possibility less than 0.1%. The dynamics of runaway positrons provides signatures that can be observed as diagnostic tools.

  13. anomalous positron peaks: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    matter ("secondary production"). Positrons may, however, also be created by dark matter particle annihilations in the galactic halo or in the magnetospheres of near-by...

  14. aps positron accumulator: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Emission and Accumulation of Antiprotons and Positrons from Supersymmetric Dark Matter HEP - Phenomenology (arXiv) Summary: We estimate the amount of antiprotons and...

  15. Positron scattering from neon and argon

    SciTech Connect (OSTI)

    Jones, A. C. L.; Makochekanwa, C.; Caradonna, P.; Slaughter, D. S.; Machacek, J. R.; McEachran, R. P.; Sullivan, J. P.; Buckman, S. J.; Stauffer, A. D.; Bray, I.; Fursa, D. V. [ARC Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, Australian National University, Canberra 0200 Australia (Australia); Department of Physics, York University, Toronto (Canada); ARC Centre for Antimatter-Matter Studies, Curtin University of Technology, G.P.O. Box U1987, Perth, Western Australia 6845 (Australia)

    2011-03-15T23:59:59.000Z

    High-resolution measurements of positron interactions with Ne and Ar are presented, as well as theoretical treatments. The data extend over a range of 0.3 to 60 eV and comprise measurements of the grand total, positonium formation, and grand total minus positronium formation cross sections. Theoretical treatments of scattering from Ne and Ar are performed under the relativistic optical potential approach, as well as calculations using the convergent close-coupling method. Comparisons of the present measurements and theories are made with previous theoretical and experimental work.

  16. alpha-11cmethyl-l-tryptophan positron emission: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of 2 Positron emission tomography CERN Preprints Summary: Positron Emission Tomography (PET) is a method for measuring biochemical and physiological processes in vivo in a...

  17. Dark Matter with multi-annihilation channels and AMS-02 positron excess and antiproton

    E-Print Network [OSTI]

    Chen, Yu-Heng; Tseng, Po-Yan

    2015-01-01T23:59:59.000Z

    AMS-02 provided the unprecedented statistics in the measurement of the positron fraction from cosmic rays. That may offer a unique opportunity to distinguish the positron spectrum coming from various dark matter (DM) annihilation channels, if DM is the source of this positron excess. Therefore, we consider the scenario that the DM can annihilate into leptonic, quark, and massive gauge boson channels simultaneously with floating branching ratios to test this hypothesis. We also study the impacts from MAX, MED, and MIN diffusion models as well as from isothermal, NFW, and Einasto DM density profiles on our results. We found that under this DM annihilation scenario it is difficult to fit the AMS-02 $\\frac{e^+}{e^++e^-}$ data while evading the PAMELA $\\bar{p}/p$ constraint, except for the combination of MED diffusion model with the Einasto density profile, where the DM mass between 450 GeV to 1.2 TeV can satisfy both data sets at 95\\% CL. Finally, we compare to the newest AMS-02 antiproton data.

  18. The Need for a Photon-Photon Collider in addition to LHC & ILC for Unraveling the Scalar Sector of the Randall-Sundrum Model

    E-Print Network [OSTI]

    Gunion, J F

    2004-01-01T23:59:59.000Z

    In the Randall-Sundrum model there can be a rich new phenomenology associated with Higgs-radion mixing. A photon-photon collider would provide a crucial complement to the LHC and a future ILC collider for fully determining the parameters of the model and definitively testing it.

  19. arXiv:1201.6345v1[hep-ph]30Jan2012 The Higgs sector of the NMFV MSSM at the ILC

    E-Print Network [OSTI]

    arXiv:1201.6345v1[hep-ph]30Jan2012 The Higgs sector of the NMFV MSSM at the ILC M. Arana-Catania1 to related works can be found. Preprint number: IFT-UAM/CSIC-12-10 Talk given by M. Arana-Catania at LCWS11 1

  20. Compact conscious animal positron emission tomography scanner

    DOE Patents [OSTI]

    Schyler, David J. (Bellport, NY); O'Connor, Paul (Bellport, NY); Woody, Craig (Setauket, NY); Junnarkar, Sachin Shrirang (Sound Beach, NY); Radeka, Veljko (Bellport, NY); Vaska, Paul (Sound Beach, NY); Pratte, Jean-Francois (Stony Brook, NY); Volkow, Nora (Chevy Chase, MD)

    2006-10-24T23:59:59.000Z

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal for an event, generating an address signal representing a detecting channel, generating a detector channel signal including the time and address signals, and generating a composite signal including the channel signal and similarly generated signals. The composite signal includes events from detectors in a block and is serially output. An apparatus that serially transfers annihilation information from a block includes time signal generators for detectors in a block and an address and channel signal generator. The PET scanner includes a ring tomograph that mounts onto a portion of an animal, which includes opposing block pairs. Each of the blocks in a block pair includes a scintillator layer, detection array, front-end array, and a serial encoder. The serial encoder includes time signal generators and an address signal and channel signal generator.

  1. Low-energy positron interactions with krypton

    SciTech Connect (OSTI)

    Makochekanwa, C.; Machacek, J. R.; Jones, A. C. L.; Caradonna, P.; Slaughter, D. S.; McEachran, R. P.; Sullivan, J. P.; Buckman, S. J.; Bellm, S.; Lohmann, B.; Fursa, D. V.; Bray, I.; Mueller, D.W.; Stauffer, A. D.; Hoshino, M. [ARC Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); ARC Centre for Antimatter-Matter Studies, The University of Adelaide, Adelaide, South Australia (Australia); ARC Centre for Antimatter-Matter Studies, Curtin University of Technology, GPO Box U1987, Perth, Western Australia 6845 (Australia); Physics Department, University of North Texas, Denton, Texas 76201 (United States); Department of Physics and Astronomy, York University, Toronto (Canada); Department of Physics, Sophia University, Chiyoda-ku, Tokyo (Japan)

    2011-03-15T23:59:59.000Z

    Cross sections for positron scattering from krypton have been measured with an energy resolution of {approx}60 meV over the energy range 0.5-60 eV. Absolute values of the grand total ({sigma}{sub GT}), positronium formation ({sigma}{sub Ps}), and grand total minus positronium formation ({sigma}{sub GT}-{sigma}{sub Ps},) cross sections are presented. Theoretical estimations of {sigma}{sub GT} and {sigma}{sub GT}-{sigma}{sub Ps} are also performed for this target using the convergent close-coupling method and the relativistic optical potential approach. We also provide experimental and theoretical results for elastic differential cross sections, for selected energies both below and above the Ps threshold. Where available, the present results are compared to both experimental and theoretical values from the literature.

  2. Applications and advances of positron beam spectroscopy: appendix a

    SciTech Connect (OSTI)

    Howell, R. H., LLNL

    1997-11-05T23:59:59.000Z

    Over 50 scientists from DOE-DP, DOE-ER, the national laboratories, academia and industry attended a workshop held on November 5-7, 1997 at Lawrence Livermore National Laboratory jointly sponsored by the DOE-Division of Materials Science, The Materials Research Institute at LLNL and the University of California Presidents Office. Workshop participants were charged to address two questions: Is there a need for a national center for materials analysis using positron techniques and can the capabilities at Lawrence Livermore National Laboratory serve this need. To demonstrate the need for a national center the workshop participants discussed the technical advantages enabled by high positron currents and advanced measurement techniques, the role that these techniques will play in materials analysis and the demand for the data. There were general discussions lead by review talks on positron analysis techniques, and their applications to problems in semiconductors, polymers and composites, metals and engineering materials, surface analysis and advanced techniques. These were followed by focus sessions on positron analysis opportunities in these same areas. Livermore now leads the world in materials analysis capabilities by positrons due to developments in response to demands of science based stockpile stewardship. There was a detailed discussion of the LLNL capabilities and a tour of the facilities. The Livermore facilities now include the worlds highest current beam of keV positrons, a scanning pulsed positron microprobe under development capable of three dimensional maps of defect size and concentration, an MeV positron beam for defect analysis of large samples, and electron momentum spectroscopy by positrons. This document is a supplement to the written summary report. It contains a complete schedule, list of attendees and the vuegraphs for the presentations in the review and focus sessions.

  3. Positive muon and the positron as probes of defects

    SciTech Connect (OSTI)

    Lynn, K G

    1980-01-01T23:59:59.000Z

    The positive muon and the positron are each being used nowadays to investigate defects in condensed matter. A brief summary of the experimental methods employed with each particle is given in this paper. Similarities and differences between the behavior of the two leptons when implanted in consensed matter are pointed out, and by means of a comparison between muon and positron data in Al it is shown that the combination of muon and positron experiments can serve as a useful new probe of defects in solids.

  4. Cross sections for atomic displacements in solids by fast positrons

    SciTech Connect (OSTI)

    Oen, Ordean S.

    1987-09-01T23:59:59.000Z

    The Mott series has been used to calculate the cross section for atomic displacements produced in elastic collisions between relativistic positrons and atomic nuclei. The Kinchin and Pease displacement model was used. Several elements spanning the atomic table were treated using positron energies ranging from threshold to several tens of MeV. The results are compared with previous calculations for relativistic electrons. It is found that for the same energy and atomic number the positron cross sections are always smaller (up to a factor of 5 or more). It is also found that the McKinley-Fesbach formula which is frequently used in radiation damage analysis is even less reliable for positrons than for electrons. 9 refs.

  5. Functional lung imaging in humans using Positron Emission Tomography

    E-Print Network [OSTI]

    Layfield, Dominick, 1971-

    2003-01-01T23:59:59.000Z

    This thesis deals with a method of functional lung imaging using Positron Emission Tomography (PET). In this technique, a radioactive tracer, nitrogen-13, is dissolved in saline solution, and injected into a peripheral ...

  6. Development of the LBNL positron emission mammography camera

    E-Print Network [OSTI]

    2002-01-01T23:59:59.000Z

    vol. 19, pp. 532-537, 2000. LBNL-50791 Submitted to IEEEal. , “The Electronics System for the LBNL Positron EmissionTransactions on Nuclear Science LBNL-50791 Development of

  7. Electromagnetic solitary pulses in a magnetized electron-positron plasma

    SciTech Connect (OSTI)

    Shukla, P. K. [RUB International Chair, International Centre for Advanced Studies in Physical Sciences, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Eliasson, B. [Institut fuer Theoretische Physik, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Stenflo, L. [Department of Physics, Linkoeping University, SE-58183 Linkoeping (Sweden)

    2011-03-15T23:59:59.000Z

    A theory for large amplitude compressional electromagnetic solitary pulses in a magnetized electron-positron (e-p) plasma is presented. The pulses, which propagate perpendicular to the external magnetic field, are associated with the compression of the plasma density and the wave magnetic field. Here the solitary wave magnetic field pressure provides the restoring force, while the inertia comes from the equal mass electrons and positrons. The solitary pulses are formed due to a balance between the compressional wave dispersion arising from the curl of the inertial forces in Faraday's law and the nonlinearities associated with the divergence of the electron and positron fluxes, the nonlinear Lorentz forces, the advection of the e-p fluids, and the nonlinear plasma current densities. The compressional solitary pulses can exist in a well-defined speed range above the Alfven speed. They can be associated with localized electromagnetic field excitations in magnetized laboratory and space plasmas composed of electrons and positrons.

  8. Next Generation Fast RF Interlock Module and ATCA Adapter for ILC High Availability RF Test Station Demonstration

    SciTech Connect (OSTI)

    Larsen, R

    2009-10-17T23:59:59.000Z

    High availability interlocks and controls are required for the ILC (International Linear Collider) L-Band high power RF stations. A new F3 (Fast Fault Finder) VME module has been developed to process both fast and slow interlocks using FPGA logic to detect the interlock trip excursions. This combination eliminates the need for separate PLC (Programmable Logic Controller) control of slow interlocks. Modules are chained together to accommodate as many inputs as needed. In the next phase of development the F3's will be ported to the new industry standard ATCA (Advanced Telecom Computing Architecture) crate (shelf) via a specially designed VME adapter module with IPMI (Intelligent Platform Management Interface). The goal is to demonstrate auto-failover and hot-swap for future partially redundant systems.

  9. Electron Positron Capture Rates and the Steady State Equilibrium Condition for Electron-Positron Plasma with Nucleons

    E-Print Network [OSTI]

    Ye-Fei Yuan

    2005-07-13T23:59:59.000Z

    The reaction rates of the beta processes for all particles at arbitrary degeneracy are derived, and an {\\it analytic} steady state equilibrium condition $\\mu_n=\\mu_p+2\\mu_e$ which results from the equality of electron and positron capture rates in the hot electron-positron plasma with nucleons is also found, if the matter is transparent to neutrinos. This simple analytic formula is valid only if electrons are nondegenerate or mildly degenerate, which is generally satisfied in the hot electron-positron plasma. Therefore, it can be used to efficiently determine the steady state of the hot matter with plenty of positrons. Based on this analytic condition, given the baryon number density and the temperature, if the nucleons are nondegenerate, only one algebraic equation for determining the electron fraction is obtained, which shows the great advantage of the analytic equilibrium condition.

  10. Study of scattering in positron emission tomography

    E-Print Network [OSTI]

    Aguiar, James

    1998-01-01T23:59:59.000Z

    an address for each coincident gamma-ray pair hence a line through the gamma-ray source. Line addresses collected at various angles are used to reconstruct an image of the radiating source. An experimental subset of the TAMU PET was used to investigate gamma-ray...

  11. Dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons

    SciTech Connect (OSTI)

    Saha, Asit, E-mail: asit-saha123@rediffmail.com, E-mail: prasantachatterjee1@rediffmail.com [Department of Mathematics, Sikkim Manipal Institute of Technology, Majitar, Rangpo, East-Sikkim 737136 (India); Department of Mathematics, Siksha Bhavana, Visva Bharati University, Santiniketan-731235 (India); Pal, Nikhil; Chatterjee, Prasanta, E-mail: asit-saha123@rediffmail.com, E-mail: prasantachatterjee1@rediffmail.com [Department of Mathematics, Siksha Bhavana, Visva Bharati University, Santiniketan-731235 (India)

    2014-10-15T23:59:59.000Z

    The dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons has been investigated in the framework of perturbed and non-perturbed Kadomtsev-Petviashili (KP) equations. Applying the reductive perturbation technique, we have derived the KP equation in electron-positron-ion magnetoplasma with kappa distributed electrons and positrons. Bifurcations of ion acoustic traveling waves of the KP equation are presented. Using the bifurcation theory of planar dynamical systems, the existence of the solitary wave solutions and the periodic traveling wave solutions has been established. Two exact solutions of these waves have been derived depending on the system parameters. Then, using the Hirota's direct method, we have obtained two-soliton and three-soliton solutions of the KP equation. The effect of the spectral index ? on propagations of the two-soliton and the three-soliton has been shown. Considering an external periodic perturbation, we have presented the quasi periodic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas.

  12. Recent progress in tailoring trap-based positron beams

    SciTech Connect (OSTI)

    Natisin, M. R.; Hurst, N. C.; Danielson, J. R.; Surko, C. M. [Physics Department, University of California, San Diego La Jolla CA 92093-0319 (United States)

    2013-03-19T23:59:59.000Z

    Recent progress is described to implement two approaches to specially tailor trap-based positron beams. Experiments and simulations are presented to understand the limits on the energy spread and pulse duration of positron beams extracted from a Penning-Malmberg (PM) trap after the particles have been buffer-gas cooled (or heated) in the range of temperatures 1000 {>=} T {>=} 300 K. These simulations are also used to predict beam performance for cryogenically cooled positrons. Experiments and simulations are also presented to understand the properties of beams formed when plasmas are tailored in a PM trap in a 5 tesla magnetic field, then non-adiabatically extracted from the field using a specially designed high-permeability grid to create a new class of electrostatically guided beams.

  13. Relativistic tunneling picture of electron-positron pair creation

    E-Print Network [OSTI]

    Anton Wöllert; Michael Klaiber; Heiko Bauke; Christoph H. Keitel

    2015-03-19T23:59:59.000Z

    The common tunneling picture of electron-positron pair creation in a strong electric field is generalized to pair creation in combined crossed electric and magnetic fields. This enhanced picture, being symmetric for electrons and positrons, is formulated in a gauge-invariant and Lorentz-invariant manner for quasistatic fields. It may be used to infer qualitative features of the pair creation process. In particular, it allows for an intuitive interpretation of how the presence of a magnetic field modifies and, in particular cases, even enhances pair creation. The creation of electrons and positrons from the vacuum may be assisted by an energetic photon, which can also be incorporated into this picture of pair creation.

  14. Positron plasma control techniques for the production of cold antihydrogen

    SciTech Connect (OSTI)

    Funakoshi, R.; Hayano, R. S. [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Amoretti, M.; Macri, M.; Testera, G.; Variola, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova, 16146 Genova (Italy); Bonomi, G. [Dipartimento di Ingegneria Meccanica, Universita di Brescia, 25123 Brescia (Italy); Dipartimento di Fisica Nucleare e Teorica, Universita di Pavia, 27100 Pavia (Italy); Bowe, P. D.; Hangst, J. S.; Madsen, N. [Department of Physics and Astronomy, University of Aarhus, 8000 Aarhus C (Denmark); Canali, C.; Carraro, C.; Lagomarsino, V.; Manuzio, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova, 16146 Genova (Italy); Dipartimento di Fisica, Universita di Genova, 16146 Genova (Italy); Cesar, C. L. [Instituto de Fisica, Universidade do Brasil, Cx Postal 68528, Rio de Janeiro 21941-972 (Brazil); Charlton, M.; Joergensen, L. V.; Mitchard, D.; Werf, D. P. van der [Department of Physics, University of Wales Swansea, Swansea SA2 8PP (United Kingdom); Doser, M. [PH Department, CERN, 1211 Geneva 23 (Switzerland)] (and others)

    2007-07-15T23:59:59.000Z

    An observation of a clear dependence of antihydrogen production on positron plasma shapes is reported. For this purpose a plasma control method has been developed combining the plasma rotating-wall technique with a mode diagnostic system. With the help of real-time and nondestructive observations, the rotating-wall parameters have been optimized. The positron plasma can be manipulated into a wide range of shapes (aspect ratio 6.5{<=}{alpha} < or approx. 80) and densities (1.5x10{sup 8}{<=}n < or approx. 7x10{sup 9} cm{sup -3}) within a short duration (25 s) compatible with the ATHENA antihydrogen production cycle.

  15. Electron-Positron Plasma Drop Formed by Ultra-Intense Laser Pulses

    E-Print Network [OSTI]

    Inga Kuznetsova; Johann Rafelski

    2012-04-25T23:59:59.000Z

    We study the initial properties and positron annihilation within a small electron-positron plasma drop formed by intense laser pulse. Such QED cascade initiated plasma is, in general, far below the chemical (particle yield) equilibrium. We find that the available electrons and positrons equilibrate kinetically, yet despite relatively high particle density, the electron-positron annihilation is very slow, suggesting a rather long lifespan of the plasma drop.

  16. Application of Positron Doppler Broadening Spectroscopy to the Measurement of the Uniformity of Composite Materials

    SciTech Connect (OSTI)

    Quarles, C. A.; Sheffield, Thomas; Stacy, Scott; Yang, Chun [Department of Physics and Astronomy, Texas Christian University, Fort Worth TX 76129 (United States)

    2009-03-10T23:59:59.000Z

    The uniformity of rubber-carbon black composite materials has been investigated with positron Doppler Broadening Spectroscopy (DBS). The number of grams of carbon black (CB) mixed into one hundred grams of rubber, phr, is used to characterize a sample. A typical concentration for rubber in tires is 50 phr. The S parameter measured by DBS has been found to depend on the phr of the sample as well as the type of rubber and carbon black. The variation in carbon black concentration within a surface area of about 5 mm diameter can be measured by moving a standard Na-22 or Ge-68 positron source over an extended sample. The precision of the concentration measurement depends on the dwell time at a point on the sample. The time required to determine uniformity over an extended sample can be reduced by running with much higher counting rate than is typical in DBS and correcting for the systematic variation of S parameter with counting rate. Variation in CB concentration with mixing time at the level of about 0.5% has been observed.

  17. Acceleration of positrons by a relativistic electron beam in the presence of quantum effects

    SciTech Connect (OSTI)

    Niknam, A. R. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of)] [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of); Aki, H.; Khorashadizadeh, S. M. [Physics Department, Birjand University, Birjand (Iran, Islamic Republic of)] [Physics Department, Birjand University, Birjand (Iran, Islamic Republic of)

    2013-09-15T23:59:59.000Z

    Using the quantum magnetohydrodynamic model and obtaining the dispersion relation of the Cherenkov and cyclotron waves, the acceleration of positrons by a relativistic electron beam is investigated. The Cherenkov and cyclotron acceleration mechanisms of positrons are compared together. It is shown that growth rate and, therefore, the acceleration of positrons can be increased in the presence of quantum effects.

  18. Electron-Positron Radiative Annihilation : Timelike Virtual Compton Scattering

    E-Print Network [OSTI]

    Asmita Mukherjee

    2010-10-01T23:59:59.000Z

    We report on a recent work proposing measurements of the deeply virtual Compton amplitude (DVCS) $\\gamma^* \\to h \\bar h \\gamma$ in the timelike kinematic domain which is accessible at electron-positron colliders via the radiative annihilation process $e^+ e^- \\to h \\bar h \\gamma$.

  19. Enhanced subthreshold electron-positron production in short laser pulses

    E-Print Network [OSTI]

    A. I. Titov; H. Takabe; B. Kampfer; A. Hosaka

    2012-05-17T23:59:59.000Z

    The emission of electron-positron pairs off a probe photon propagating through a polarized short-pulsed electromagnetic (e.g.\\ laser) wave field is analyzed. A significant increase of the total cross section of pair production in the subthreshold region is found for decreasing laser pulse duration even in case of moderate laser pulse intensities.

  20. PALSfit: A computer program for analysing positron lifetime spectra

    E-Print Network [OSTI]

    .2 ResolutionFit 35 6 Control files 35 6.1 PositronFit control file 36 6.2 ResolutionFit control file 39]. Taking advantage of a new Graphical User Interface (GUI) for Windows, a number of user friendly facilities have been incorporated, in particular graphics displays. The two cornerstones in PALSfit

  1. Modulational instability of ion acoustic wave with warm ions in electron-positron-ion plasmas

    SciTech Connect (OSTI)

    Mahmood, S. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan); Department of Physics and Applied Mathematics, PIEAS, P.O. Nilore, Islamabad 44000 (Pakistan); Siddiqui, Sadiya [Department of Physics and Applied Mathematics, PIEAS, P.O. Nilore, Islamabad 44000 (Pakistan); Jehan, Nusrat [Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan)

    2011-05-15T23:59:59.000Z

    The nonlinear amplitude modulation of ion acoustic wave is studied in the presence of warm ions in unmagnetized electron-positron-ion plasmas. The Krylov-Bogoliubov-Mitropolsky (KBM) method is used to derive the nonlinear Schroedinger equation. The dispersive and nonlinear coefficients are obtained which depends on the ion temperature and positron density in electron-positron-ion plasmas. The modulationally stable and unstable regions are studied numerically for a wide range of wave number. It is found that both ion temperature and positron density play a significant role in the formation of bright and dark envelope solitons in electron-positron-ion plasmas.

  2. Signatures of a two million year old supernova in the spectra of cosmic ray protons, antiprotons and positrons

    E-Print Network [OSTI]

    Kachelriess, M; Semikoz, D V

    2015-01-01T23:59:59.000Z

    The locally observed cosmic ray spectrum has several puzzling features, such as the excess of positrons and antiprotons above $\\sim 20$ GeV and the discrepancy in the slopes of the spectra of cosmic ray protons and heavier nuclei in the TeV-PeV energy range. We show that these features are consistently explained by a nearby source which was active $\\sim 2$ Myr ago and has injected $(1-2)\\times 10^{50}$ erg in cosmic rays. The transient nature of the source and its overall energy budget point to the supernova origin of this local cosmic ray source. The age of the supernova suggests that the local cosmic ray injection was produced by the same supernova that has deposited $^{60}$Fe isotopes in the deep ocean crust.

  3. Magnetohydrodynamic spin waves in degenerate electron-positron-ion plasmas

    SciTech Connect (OSTI)

    Mushtaq, A. [TPPD, PINSTECH Nilore, 44000 Islamabad (Pakistan); National Center for Physics, Shahdrah Valley Road, 44000 Islamabad (Pakistan); Maroof, R.; Ahmad, Zulfiaqr [Institute of Physics and Electronics, University of Peshawar, 25000 Peshawar (Pakistan); Qamar, A. [National Center for Physics, Shahdrah Valley Road, 44000 Islamabad (Pakistan); Institute of Physics and Electronics, University of Peshawar, 25000 Peshawar (Pakistan)

    2012-05-15T23:59:59.000Z

    Low frequency magnetosonic waves are studied in magnetized degenerate electron-positron-ion plasmas with spin effects. Using the fluid equations of magnetoplasma with quantum corrections due to the Bohm potential, temperature degeneracy, and spin magnetization energy, a generalized dispersion relation for oblique magnetosonic waves is derived. Spin effects are incorporated via spin force and macroscopic spin magnetization current. For three different values of angle {theta}, the generalized dispersion relation is reduced to three different relations under the low frequency magnetohydrodynamic assumptions. It is found that the effect of quantum corrections in the presence of positron concentration significantly modifies the dispersive properties of these modes. The importance of the work relevant to compact astrophysical bodies is pointed out.

  4. A model for positron binding to polar molecules

    E-Print Network [OSTI]

    Gribakin, G F

    2015-01-01T23:59:59.000Z

    A model for positron binding to polar molecules is considered by combining the dipole potential outside the molecule with a strongly repulsive core of a given radius. Using existing experimental data on binding energies leads to unphysically small core radii for all of the molecules studied. This suggests that electron-positron correlations neglected in the simple model play a large role in determining the binding energy. We account for these by including polarization potential via perturbation theory. The improved model enables reliable predictions of binding energies to be made for a range of polar organic molecules and hydrogen cyanide, whose binding energy is known from accurate quantum chemistry calculations. The model explains the linear dependence of the binding energies on the polarizability inferred from the experimental data [Danielson et al 2009 J. Phys. B: At. Mol. Opt. Phys. 42 235203].

  5. Variable energy positron measurements at nitrogen ion bombarded steel surfaces

    SciTech Connect (OSTI)

    Brauer, G.; Kolitsch, A. [Research Centre Rossendorf, Inc., Dresden (Germany); Schut, H.; Veen, A. van [TU Delft (Netherlands). Interfaculty Reactor Inst.

    1996-12-31T23:59:59.000Z

    Nitrogen ion bombardment of steel samples has been studied by utilizing the Delft variable energy positron beam facility. The energy of the beam was varied between 250 eV and 25 keV and a line-shape parameter S describing the annihilation radiation has been measured. By use of the VEPFIT fitting program, up to five different layers, each having different densities, could be identified and characterized. The results show that carbon layers deposited during nitrogen implantation can be observed. A relation between the measured depth profiles of nitrogen, carbon and oxygen by Elastic Recoil Detection Analysis (ERDA) and the results of positron annihilation is given and discussed. The wear and friction properties of the steel surfaces before and after nitrogen implantation are presented.

  6. Simulations of slow positron production using a low-energy electron accelerator

    SciTech Connect (OSTI)

    O'Rourke, B. E.; Kinomura, A.; Kuroda, R.; Ohdaira, T.; Oshima, N.; Suzuki, R. [National Institute of Advanced Industrial Science and Technology (AIST), AIST-Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Hayashizaki, N. [Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Minehara, E. J. [The Wakasa Wan Energy Research Centre, 64-52-1 Nagatani, Tsuruga, Fukui 941-0821 (Japan)

    2011-06-15T23:59:59.000Z

    Monte Carlo simulations of slow positron production via energetic electron interaction with a solid target have been performed. The aim of the simulations was to determine the expected slow positron beam intensity from a low-energy, high-current electron accelerator. By simulating (a) the fast positron production from a tantalum electron-positron converter and (b) the positron depth deposition profile in a tungsten moderator, the slow positron production probability per incident electron was estimated. Normalizing the calculated result to the measured slow positron yield at the present AIST linear accelerator, the expected slow positron yield as a function of energy was determined. For an electron beam energy of 5 MeV (10 MeV) and current 240 {mu}A (30 {mu}A), production of a slow positron beam of intensity 5 x 10{sup 6} s{sup -1} is predicted. The simulation also calculates the average energy deposited in the converter per electron, allowing an estimate of the beam heating at a given electron energy and current. For low-energy, high-current operation the maximum obtainable positron beam intensity will be limited by this beam heating.

  7. Status of the Advanced Photon Source (APS) linear accelerator

    SciTech Connect (OSTI)

    White, M.; Berg, W.; Fuja, R.; Grelick, A.; Mavrogenes, G.; Nassiri, A.; Russell, T.; Wesolowski, W.

    1993-08-01T23:59:59.000Z

    A 2856-MHz S-band, 450-MeV electron/positron linear accelerator is the first part of the injector for the Advanced Photon Source (APS) 7-GeV storage ring. Construction of the APS linac is currently nearing completion, and commissioning will begin in July 1993. The linac and its current status are discussed in this paper.

  8. Enhancing $t\\bar{t}hh$ production through CP-violating top-Higgs interaction at the LHC, ILC and a 100 TeV collider

    E-Print Network [OSTI]

    Ning Liu; Yanming Zhang; Jinzhong Han; Bingfang Yang

    2015-03-30T23:59:59.000Z

    The measurement of Higgs self-coupling is one of the most crucial physics goals at the future colliders. At the LHC, the di-Higgs production is a main way to measure the Higgs trilinear coupling. As a complementary to the di-Higgs production, $t \\bar{t} hh$ process may open a new avenue to measure di-Higgs physics at the LHC and a future 100 TeV $pp$ collider or a high energy $e^+e^-$ collider since the extra $t\\bar t$ in the final states may efficiently suppress the backgrounds. However, such a kind of process is also controlled by the top-Higgs coupling. In this work, we investigate the impact of CP-violating top-Higgs coupling on $t\\bar{t}hh$ production at the LHC, ILC and a 100 TeV hadron collider under the current Higgs data. Within 2$\\sigma$ Higgs data allowed parameter region, we find that the cross section of $t\\bar{t}hh$ at the LHC-14 TeV, ILC-1 TeV and VHE-LHC/SPPC-100 TeV can be enhanced up to 2.1 times the SM predictions. The future precise measurement of Higgs coupling will reveal the nature of top-Higgs interaction and improve the sensitivity of the determination of Higgs self-coupling through $t\\bar{t}hh$ production.

  9. Enhancing $t\\bar{t}hh$ production through CP-violating top-Higgs interaction at the LHC, ILC and a 100 TeV collider

    E-Print Network [OSTI]

    Liu, Ning; Han, Jinzhong; Yang, Bingfang

    2015-01-01T23:59:59.000Z

    The measurement of Higgs self-coupling is one of the most crucial physics goals at the future colliders. At the LHC, the di-Higgs production is a main way to measure the Higgs trilinear coupling. As a complementary to the di-Higgs production, $t \\bar{t} hh$ process may open a new avenue to measure di-Higgs physics at the LHC and a future 100 TeV $pp$ collider or a high energy $e^+e^-$ collider since the extra $t\\bar t$ in the final states may efficiently suppress the backgrounds. However, such a kind of process is also controlled by the top-Higgs coupling. In this work, we investigate the impact of CP-violating top-Higgs coupling on $t\\bar{t}hh$ production at the LHC, ILC and a 100 TeV hadron collider under the current Higgs data. Within 2$\\sigma$ Higgs data allowed parameter region, we find that the cross section of $t\\bar{t}hh$ at the LHC-14 TeV, ILC-1 TeV and VHE-LHC/SPPC-100 TeV can be enhanced up to 2.1 times the SM predictions. The future precise measurement of Higgs coupling will reveal the nature of t...

  10. Positron interactions with water–total elastic, total inelastic, and elastic differential cross section measurements

    SciTech Connect (OSTI)

    Tattersall, Wade [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia) [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia); Chiari, Luca [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia)] [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia); Machacek, J. R.; Anderson, Emma; Sullivan, James P. [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)] [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); White, Ron D. [Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia)] [Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland (Australia); Brunger, M. J. [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia) [Centre for Antimatter-Matter Studies, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide 5001, South Australia (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); Buckman, Stephen J. [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia) [Centre for Antimatter-Matter Studies, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia); Garcia, Gustavo [Instituto de F?sica Fundamental, Consejo Superior de Investigationes Cient?ficas (CSIC), Serrano 113-bis, E-28006 Madrid (Spain)] [Instituto de F?sica Fundamental, Consejo Superior de Investigationes Cient?ficas (CSIC), Serrano 113-bis, E-28006 Madrid (Spain); Blanco, Francisco [Departamento de F?sica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain)] [Departamento de F?sica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

    2014-01-28T23:59:59.000Z

    Utilising a high-resolution, trap-based positron beam, we have measured both elastic and inelastic scattering of positrons from water vapour. The measurements comprise differential elastic, total elastic, and total inelastic (not including positronium formation) absolute cross sections. The energy range investigated is from 1 eV to 60 eV. Comparison with theory is made with both R-Matrix and distorted wave calculations, and with our own application of the Independent Atom Model for positron interactions.

  11. Simulations of slow positron production using a low energy electron accelerator

    E-Print Network [OSTI]

    O'Rourke, B E; Kinomura, A; Kuroda, R; Minehara, E; Ohdaira, T; Oshima, N; Suzuki, R

    2011-01-01T23:59:59.000Z

    Monte Carlo simulations of slow positron production via energetic electron interaction with a solid target have been performed. The aim of the simulations was to determine the expected slow positron beam intensity from a low energy, high current electron accelerator. By simulating (a) the fast positron production from a tantalum electron-positron converter and (b) the positron depth deposition profile in a tungsten moderator, the slow positron production probability per incident electron was estimated. Normalizing the calculated result to the measured slow positron yield at the present AIST LINAC the expected slow positron yield as a function of energy was determined. For an electron beam energy of 5 MeV (10 MeV) and current 240 $\\mu$A (30 $\\mu$A) production of a slow positron beam of intensity 5 $\\times$ 10$^{6}$ s$^{-1}$ is predicted. The simulation also calculates the average energy deposited in the converter per electron, allowing an estimate of the beam heating at a given electron energy and current. For...

  12. The terminal bulk Lorentz factor of relativistic electron-positron jet

    E-Print Network [OSTI]

    N. Renaud; G. Henri

    1997-06-16T23:59:59.000Z

    We present numerical simulation of bulk Lorentz factor of relativistic electron positron jet driven by Compton rocket effect from accretion disk radiation. The plasma is assumed to have a power-law energy distribution and is continuously reheated to compensate for radiation losses. We include Klein-Nishina (hereafter KN) corrections, and study the role of energy upper cut-off, spectral index, and source compactness. We determine terminal bulk Lorentz factor in the case of supermassive black holes relevant to AGN and stellar black holes relevant to galactic microquasars. In the latter case, effects of KN corrections are more important and induce terminal bulk Lorentz factor smaller than in the former case. The result can explain the low bulk Lorentz factors for galactic sources (GRS1915+105, GROJ1655-40) compared to extragalactic ones. We also take into account the influence of the size of the accretion disk; if the external radius is small enough, the bulk Lorentz factor can be as high as 60, which is comparable to the values needed to explain extragalactic gamma-ray bursts.

  13. Positron Excess, Luminous-Dark Matter Unification and Family Structure

    E-Print Network [OSTI]

    Paul H. Frampton; Pham Q. Hung

    2009-04-16T23:59:59.000Z

    It is commonly assumed that dark matter may be composed of one or at most a few elementary particles. PAMELA data present a window of opportunity into a possible relationship between luminous and dark matter. Along with ATIC data the two positron excesses are interpreted as a reflection of dark matter family structure. In a unified model it is predicted that at least a third enhancement might show up at a different energy. The strength of the enhancements however depends on interfamily mixing angles.

  14. Tile HCAL Test Beam Analysis: Positron and Hadron Studies

    E-Print Network [OSTI]

    Riccardo Fabbri

    2009-02-09T23:59:59.000Z

    The CALICE collaboration has constructed a hadronic sandwich calorimeter prototype with 7608 scintillating plates, individually read out by multi-pixel silicon photomultipliers (SiPMs). For the first time ever the read out is performed using SiPMs on a large scale. Results of test beam operations with muon, positron and hadron beams at CERN are presented here, validating the feasibility of the novel SiPM technology. Results of the application of the particle flow approach in shower energy reconstruction are presented for the first time ever using real data.

  15. Magnetically bound states of electronic and positronic hydrogen ions: The case of zero orbital angular momentum

    E-Print Network [OSTI]

    California at San Diego, University of

    orbital angular momentum J, and zero net spin i.e., it is a singlet state 2 . Furthermore a positronMagnetically bound states of electronic and positronic hydrogen ions: The case of zero orbital in a uniform magnetic field B, concentrating on states with zero orbital angular momentum J. It is shown

  16. What is the fate of runaway positrons in tokamaks? Hong Qin,1,2,a)

    E-Print Network [OSTI]

    tools. VC 2014 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4882435] Positron, the anti-particle is typically above 10 MeV, most of their "children" positrons are born relativistic and can be acceler- ated

  17. F]-Fluorodeoxyglucose Positron Emission Tomography and Computed Tomography in Response

    E-Print Network [OSTI]

    Hemminki, Akseli

    , and [18 F]-FDG-uptake was quantitated with small animal PET/CT. Second, we describe a retrospective molecules. Here we investigated the prognostic utility of CT and [18 F]-fluor- odeoxyglucose (FDG) positron[18 F]-Fluorodeoxyglucose Positron Emission Tomography and Computed Tomography in Response

  18. Use of Physical Models to Facilitate Transfer of Physics Learning to Understand Positron Emission Tomography*

    E-Print Network [OSTI]

    Zollman, Dean

    interactive learning with the aid of physical models. Three different types of non-scaffolded transfer haveUse of Physical Models to Facilitate Transfer of Physics Learning to Understand Positron Emission, positron emission tomography, transfer of learning PACS: 01.40Fk Supported by the National Science

  19. Sympathetically cooled and compressed positron plasma B. M. Jelenkovic,1,2

    E-Print Network [OSTI]

    progress has been obtained over the last decade in trapping and cooling positrons 8­14 . Recent experimentsSympathetically cooled and compressed positron plasma B. M. Jelenkovic´,1,2 A. S. Newbury,1, * J. J, USA Received 27 February 2003; published 18 June 2003 We report sympathetic cooling and compression

  20. Multiple scattering measurements of energetic positrons in a thin gold polycrystal

    E-Print Network [OSTI]

    Golovchenko, Jene A.

    to determine the angular distribution of emergent positrons. Image plate sensitivity was measured for high-energy considerations. Ó 2000 Elsevier Science B.V. All rights reserved. PACS: 34.85.+x; 11.80.La Keywords: Positron: Department of Engineer- ing Physics, Faculty of Engineering, Alexandria University, Alexandria 21544, Egypt

  1. PARTICLE ACCELERATION AND MAGNETIC FIELD GENERATION IN ELECTRON-POSITRON RELATIVISTIC SHOCKS

    E-Print Network [OSTI]

    Nishikawa, Ken-Ichi

    PARTICLE ACCELERATION AND MAGNETIC FIELD GENERATION IN ELECTRON-POSITRON RELATIVISTIC SHOCKS K are responsible for particle (electron, positron, and ion) acceleration. Using a three-dimensional relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic

  2. NEUTRON DAMAGE IN REACTOR PRESSURE-VESSEL STEEL EXAMINED WITH POSITRON ANNIHILATION LIFETIME SPECTROSCOPY

    E-Print Network [OSTI]

    Motta, Arthur T.

    NEUTRON DAMAGE IN REACTOR PRESSURE-VESSEL STEEL EXAMINED WITH POSITRON ANNIHILATION LIFETIME-vessel steels. We irradiated samples ofASTM A508 nuclear reactor pressure-vessel steel to fast neutron 17 2 (PALS) to study the effects of neutron damage in the steels on positron lifetimes. Non

  3. Observation of Cosmic Ray Positrons with the CAPRICE98 Balloon-borne Experiment

    E-Print Network [OSTI]

    Morselli, Aldo

    at energies above 5 GeV. The RICH was complemented with a silicon-tungsten imaging calorimeter. Together primary production sites. Hence, the positron fraction / ( + ) is a sensitive quantity for studying production and propagation of electrons and positrons. Previous observations (see, e.g., Golden et al. 1987

  4. Streaking at high energies with electrons and positrons

    SciTech Connect (OSTI)

    Ipp, Andreas; Evers, Joerg; Keitel, Christoph H.; Hatsagortsyan, Karen Z. [Institut fuer Theoretische Physik, Technische Universitaet Wien, 1040 Vienna (Austria); Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

    2012-07-09T23:59:59.000Z

    State-of-the-art attosecond metrology deals with the detection and characterization of photon pulses with typical energies up to the hundreds of eV and time resolution of several tens of attoseconds. Such short pulses are used for example to control the motion of electrons on the atomic scale or to measure inner-shell atomic dynamics. The next challenge of time-resolving the inner-nuclear dynamics, transient meson states and resonances requires photon pulses below attosecond duration and with energies exceeding the MeV scale. Here we discuss a detection scheme for time-resolving high-energy gamma ray pulses down to the zeptosecond timescale. The scheme is based on the concept of attosecond streak imaging, but instead of conversion of photons into electrons in a nonlinear medium, the high-energy process of electron-positron pair creation is utilized. These pairs are produced in vacuum through the collision of a test pulse to be characterized with an intense laser pulse, and they acquire additional energy and momentum depending on their phase in the streaking pulse at the moment of production. A coincidence measurement of the electron and positron momenta after the interaction provides information on the pair production phase within the streaking pulse. We examine the limitations imposed by quantum radiation reaction in multiphoton Compton scattering on this detection scheme, and discuss other necessary conditions to render the scheme feasible in the upcoming Extreme Light Infrastructure (ELI) laser facility.

  5. Classical Mechanics of Collinear Positron-Hydrogen Scattering

    E-Print Network [OSTI]

    Lee, Min-Ho; Moon, Jin-Sung; Choi, Nark Nyul; Kim, Dae-Soung

    2015-01-01T23:59:59.000Z

    We study the classical dynamics of the collinear positron-hydrogen scattering system below the three-body breakup threshold. Observing the chaotic behavior of scattering time signals, we in- troduce a code system appropriate to a coarse grained description of the dynamics. And, for the purpose of systematic analysis of the phase space structure, a surface of section is introduced being chosen to match the code system. Partition of the surface of section leads us to a surprising conjec- ture that the topological structure of the phase space of the system is invariant under exchange of the dynamical variables of proton with those of positron. It is also found that there is a finite set of forbidden patterns of symbol sequences. And the shortest periodic orbit is found to be stable, around which invariant tori form an island of stability in the chaotic sea. Finally we discuss a possible quantum manifestation of the classical phase space structure relevant to resonances in scattering cross sections.

  6. Positron-production Experiment In Tungsten Crystal Using 4 And 8-gev Channeling Electrons At The Kekb Injector Linac

    E-Print Network [OSTI]

    Suwada, T; Chehab, R; Enomoto, A; Furukawa, K; Kakihara, K; Kamitani, T; Ogawa, Y; Ohsawa, S; Okuno, H; Oogoe, T; Fujita, T; Umemori, K; Yoshida, K; Ababiy, V; Potylitsin, A P; Vnukov, I E; Hamatsu, R; Sasahara, K

    2002-01-01T23:59:59.000Z

    Positron-production Experiment In Tungsten Crystal Using 4 And 8-gev Channeling Electrons At The Kekb Injector Linac

  7. Positron-production Experiment By 8-gev Channeling Electrons In Crystal Tungsten At The Kekb Injector Linac

    E-Print Network [OSTI]

    Suwada, T

    2001-01-01T23:59:59.000Z

    Positron-production Experiment By 8-gev Channeling Electrons In Crystal Tungsten At The Kekb Injector Linac

  8. Electrostatic solitary ion waves in dense electron-positron-ion magnetoplasma

    SciTech Connect (OSTI)

    Jehan, Nusrat [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Salahuddin, M. [Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Mahmood, S. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2009-04-15T23:59:59.000Z

    The nonlinear coupled ion-acoustic and ion-cyclotron waves propagating obliquely to the external magnetic field in dense collisionless electron-positron-ion magnetoplasma are investigated using Sagdeev potential method. A semiclassical approach is used. Electrons and positrons are treated as degenerate Fermi gases described by Thomas-Fermi density distribution and ions behave as classical gas. It is found that the presence of degenerate positrons in a dense Thomas-Fermi plasma significantly modifies the structure of solitary waves by restricting the electrostatic potential to a certain maximum value which depends upon the concentration of positrons in the system. It is also noted that only subsonic humplike solitary waves can exist and for a given angle of propagation, the presence of degenerate positrons diminishes the amplitude as well as width of the solitary wave.

  9. Effect of positron-atom interactions on the annihilation gamma spectra of molecules

    E-Print Network [OSTI]

    Green, D G; Wang, F; Gribakin, G F; Surko, C M

    2012-01-01T23:59:59.000Z

    Calculations of gamma spectra for positron annihilation on a selection of molecules, including methane and its fluoro-substitutes, ethane, propane, butane and benzene are presented. The annihilation gamma spectra characterise the momentum distribution of the electron-positron pair at the instant of annihilation. The contribution to the gamma spectra from individual molecular orbitals is obtained from electron momentum densities calculated using modern computational quantum chemistry density functional theory tools. The calculation, in its simplest form, effectively treats the low-energy (thermalised, room-temperature) positron as a plane wave and gives annihilation gamma spectra that are about 40% broader than experiment, although the main chemical trends are reproduced. We show that this effective "narrowing" of the experimental spectra is due to the action of the molecular potential on the positron, chiefly, due to the positron repulsion from the nuclei. It leads to a suppression of the contribution of smal...

  10. Feasibility of a minimum bias analysis of $e^+e^-\\to ZH \\to q\\bar{q}+X$ at a 250 GeV ILC

    E-Print Network [OSTI]

    Yacine Haddad

    2014-04-11T23:59:59.000Z

    The precision measurements of the Higgs properties is crucial for a better understanding of electroweak symmetry breaking. It can be first achieved at the ILC\\pcite{Behnke2013} at $\\sqrt{s}=250\\rm ~GeV$ via the Higgs-strahlung production process $e^+e^-\\rightarrow ZH$. The hadronic decay mode $Z\\rightarrow \\bar{q}q$ constitutes more than $65%$ of the total, a factor 10 more than $Z\\rightarrow \\mu\\mu$. An analysis based solely on the $Z$ jet pair information could thus lead to a high statistics and provide a minimum biased Higgs sample. A study of the feasibility of such analysis is shown here, based on $e^+e^-$ simulated collisions at $250\\rm ~GeV$ in center of mass, for the equivalent integrated luminosity of $500\\rm ~fb^{-1}$ and using a fast simulation of the ILD detector.

  11. The Connection Between the Positron Fraction Anomaly and the Spectral Features in Galactic Cosmic-Ray Hadrons

    E-Print Network [OSTI]

    Tomassetti, N

    2015-01-01T23:59:59.000Z

    Recent data on Galactic cosmic-ray (CR) leptons and hadrons gave rise to two exciting problems: on the lepton side, the origin of the rise of the CR positron fraction e+/(e- + e+) at ~10 - 300 GeV of energy; on the hadron side, the nature of the spectral hardening observed in CR protons and nuclei at ~TeV energies. The lepton anomaly indicates the existence of a nearby e+/- source. It has been proposed that high-energy positrons can be produced inside nearby supernova remnants (SNRs) via interactions of CR hadrons with the ambient medium. A distinctive prediction of this mechanism is a high-energy rise of the boron-to-carbon ratio, which has not been observed. It also requires old SNRs at work (with ineffective magnetic field amplification and slow shock speed), that cannot account for the CR hadronic spectra observed up to the knee energies (~5 PeV). We propose a new picture where, in addition to such a nearby CR accelerator, the high-energy spectrum of CR hadrons is provided by the large-scale population of...

  12. ILC Citizens' Task Force

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh School footballHydrogen andHypernuclei in Hall link toall2, Issue,III

  13. A Central Positron Source to Perform the Timing Alignment of Detectors in a PET

    E-Print Network [OSTI]

    Thompson, Chris

    . The time delay before the gamma ray is detected by the scanner's conventional gamma ray detectors for the apparent time at which a gamma ray is detected by each crystal, so that when a true coincidence is detected a precise time reference. Aligning the detectors in a PET scanner so that they can detect coincident gamma

  14. Solitary and shock waves in magnetized electron-positron plasma

    SciTech Connect (OSTI)

    Lu, Ding; Li, Zi-Liang; Abdukerim, Nuriman; Xie, Bai-Song, E-mail: bsxie@bnu.edu.cn [Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, and College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China)] [Key Laboratory of Beam Technology and Materials Modification of the Ministry of Education, and College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China)

    2014-02-15T23:59:59.000Z

    An Ohm's law for electron-positron (EP) plasma is obtained. In the framework of EP magnetohydrodynamics, we investigate nonrelativistic nonlinear waves' solutions in a magnetized EP plasma. In the collisionless limit, quasistationary propagating solitary wave structures for the magnetic field and the plasma density are obtained. It is found that the wave amplitude increases with the Mach number and the Alfvén speed. However, the dependence on the plasma temperature is just the opposite. Moreover, for a cold EP plasma, the existence range of the solitary waves depends only on the Alfvén speed. For a hot EP plasma, the existence range depends on the Alfvén speed as well as the plasma temperature. In the presence of collision, the electromagnetic fields and the plasma density can appear as oscillatory shock structures because of the dissipation caused by the collisions. As the collision frequency increases, the oscillatory shock structure becomes more and more monotonic.

  15. The terminal bulk Lorentz factor of relativistic electron-positron jets

    E-Print Network [OSTI]

    N. Renaud; G. Henri

    1998-04-17T23:59:59.000Z

    We present numerical simulation of bulk Lorentz factor of relativistic electron-positron jet driven by Compton rocket effect from accretion disc radiation. The plasma is assumed to have a power-law distribution $n_{e}(\\gamma) \\propto \\gamma^{-s}$ whith $1 terminal bulk Lorentz factor in the case of supermassive black holes relevant to AGN and stellar black holes relevant to galactic microquasars. In the latter case, Klein-Nishina cross section effect are more important, and induce terminal bulk Lorentz factor smaller than in the former case. Our result are in good agreement with bulk Lorentz factors observed in galactic sources (GRS1915+105, GROJ1655-40) and extragalactic ones. Differences in scattered radiation and acceleration mechanism efficiency in AGN environment can be responsible for the variety of relativistic motion in those objects. We also take into account the influence of the size of the accretion disc; if the external radius is small enough, the bulk Lorentz factor can be as high as 60.

  16. Oblique modulation of ion-acoustic waves and envelope solitons in electron-positron-ion plasma

    SciTech Connect (OSTI)

    Jehan, Nusrat [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Salahuddin, M. [Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2009-06-15T23:59:59.000Z

    The effect of oblique modulation on the amplitude dynamics of ion-acoustic wave propagating in a collisionless electron-positron-ion plasma is investigated. Using Krylov-Bogoliubov-Mitropolsky (KBM) perturbation method, a nonlinear Schroedinger (NLS) equation is derived which governs the evolution of obliquely modulated ion-acoustic envelope excitations. It is found that the presence of positron component significantly modifies the stability domains for small angles of propagation with the direction of modulation. The stationary solutions of NLS equation, i.e., bright and dark envelope solitons, become narrower as the concentration of positron component increases.

  17. Scaling the Yield of Laser-Driven Electron-Positron Jets to Laboratory Astrophysical Applications

    E-Print Network [OSTI]

    Chen, Hui; Link, A; Hazi, A; Hill, M; Hoarty, D; James, S; Kerr, S; Meyerhofer, D D; Myatt, J; Park, J; Sentoku, Y; Williams, G J

    2015-01-01T23:59:59.000Z

    We report new experimental results obtained on three different laser facilities that show directed laser-driven relativistic electron-positron jets with up to 30 times larger yields than previously obtained and a quadratic (~ E^2) dependence of the positron yield on the laser energy. This favorable scaling stems from a combination of higher energy electrons due to increased laser intensity and the recirculation of MeV electrons in the mm-thick target. Based on this scaling, first principles simulations predict the possibility of using such electron-positron jets, produced at upcoming high-energy laser facilities, to probe the physics of relativistic collisionless shocks in the laboratory.

  18. Scattering of low-energy electrons and positrons by atomic beryllium: Ramsauer-Townsend effect

    E-Print Network [OSTI]

    Reid, David D

    2014-01-01T23:59:59.000Z

    Total cross sections for the scattering of low-energy electrons and positrons by atomic beryllium in the energy range below the first inelastic thresholds are calculated. A Ramsauer-Townsend minimum is seen in the electron scattering cross sections, while no such effect is found in the case of positron scattering. A minimum total cross section of 0.016 a.u. at 0.0029 eV is observed for the electron case. In the limit of zero energy, the cross sections yield a scattering length of -0.61 a.u. for electron and +13.8 a.u. for positron scattering.

  19. Brain Imaging with Positron Emission Tomography: Quantification and Biomedical Applications in Alzheimer's Disease and Brain Tumors

    E-Print Network [OSTI]

    Wardak, Mirwais

    2013-01-01T23:59:59.000Z

    AB, Elson LM. The human brain coloring book. 1st ed. New21. Toga AW, Mazziotta JC. Brain mapping : the systems. SanSR, Phelps ME. Imaging Brain Function with Positron Emission

  20. Plant Y(t)e(t)r(t)

    E-Print Network [OSTI]

    Conversion Algorithm Frequecny Power Pressure Controller Sinus-6 HPM Source Calculated Spark Gap Pressure ILC

  1. Determination of interfacial states in solid heterostructures using a variable-energy positron beam

    DOE Patents [OSTI]

    Asokakumar, P.P.V.; Lynn, K.G.

    1993-04-06T23:59:59.000Z

    A method and means is provided for characterizing interfacial electron states in solid heterostructures using a variable energy positron beam to probe the solid heterostructure. The method includes the steps of directing a positron beam having a selected energy level at a point on the solid heterostructure so that the positron beam penetrates into the solid heterostructure and causes positrons to collide with the electrons at an interface of the solid heterostructure. The number and energy of gamma rays emitted from the solid heterostructure as a result of the annihilation of positrons with electrons at the interface are detected. The data is quantified as a function of the Doppler broadening of the photopeak about the 511 keV line created by the annihilation of the positrons and electrons at the interface, preferably, as an S-parameter function; and a normalized S-parameter function of the data is obtained. The function of data obtained is compared with a corresponding function of the Doppler broadening of the annihilation photopeak about 511 keV for a positron beam having a second energy level directed at the same material making up a portion of the solid heterostructure. The comparison of these functions facilitates characterization of the interfacial states of electrons in the solid heterostructure at points corresponding to the penetration of positrons having the particular energy levels into the interface of the solid heterostructure. Accordingly, the invention provides a variable-energy non-destructive probe of solid heterostructures, such as SiO[sub 2]/Si, MOS or other semiconductor devices.

  2. Langmuir Shock Pulses in a Rotating Electron-Positron-Ion Magnetoplasma

    SciTech Connect (OSTI)

    El-Labany, S. K. [Department of Physics, Faculty of Science-Damietta, Mansoura University, New Damietta City 34517 (Egypt); Moslem, W. M.; El-Awady, E. I. [Department of Physics, Faculty of Science, Port Said University, Port Said (Egypt)

    2010-12-14T23:59:59.000Z

    A theoretical investigation has been made for nonlinear Langmuir structures (Langmuir shock waves) in a rotating electron-positron-ion magnetoplasma with stationary positive ions. For this purpose, the reductive perturbation technique is employed to the hydrodynamical electrons/positrons fluid equations and Poisson equation, obtaining extended Zakharov-Kuznetsov (EZK) equation. The latter has been solved analytically and the features of the nonlinear excitations are investigated numerically. Furthermore, the propagation condition for the nonlinear structures is examined.

  3. Electromagnetic cascade in high energy electron, positron, and photon interactions with intense laser pulses

    E-Print Network [OSTI]

    S. S. Bulanov; C. B. Schroeder; E. Esarey; W. P. Leemans

    2013-06-05T23:59:59.000Z

    The interaction of high energy electrons, positrons, and photons with intense laser pulses is studied in head-on collision geometry. It is shown that electrons and/or positrons undergo a cascade-type process involving multiple emissions of photons. These photons can consequently convert into electron-positron pairs. As a result charged particles quickly lose their energy developing an exponentially decaying energy distribution, which suppresses the emission of high energy photons, thus reducing the number of electron-positron pairs being generated. Therefore, this type of interaction suppresses the development of the electromagnetic avalanche-type discharge, i.e., the exponential growth of the number of electrons, positrons, and photons does not occur in the course of interaction. The suppression will occur when 3D effects can be neglected in the transverse particle orbits, i.e., for sufficiently broad laser pulses with intensities that are not too extreme. The final distributions of electrons, positrons, and photons are calculated for the case of a high energy e-beam interacting with a counter-streaming, short intense laser pulse. The energy loss of the e-beam, which requires a self-consistent quantum description, plays an important role in this process, as well as provides a clear experimental observable for the transition from the classical to quantum regime of interaction.

  4. The Intense Slow Positron Beam Facility at the NC State University PULSTAR Reactor

    SciTech Connect (OSTI)

    Hawari, Ayman I.; Moxom, Jeremy; Hathaway, Alfred G.; Brown, Benjamin [Nuclear Engineering/Nuclear Reactor Program, North Carolina State University, P.O. Box 7909, Raleigh NC 27695 (United States); Gidley, David W.; Vallery, Richard [Physics Department, University of Michigan, 450 Church Street, Ann Arbor MI 48109 (United States); Xu, Jun [Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, Oak Ridge TN 37831 (United States)

    2009-03-10T23:59:59.000Z

    An intense slow positron beam is in its early stages of operation at the 1-MW open-pool PULSTAR research reactor at North Carolina State University. The positron beam line is installed in a beam port that has a 30-cmx30-cm cross sectional view of the core. The positrons are created in a tungsten converter/moderator by pair-production using gamma rays produced in the reactor core and by neutron capture reactions in cadmium cladding surrounding the tungsten. Upon moderation, slow ({approx}3 eV) positrons that are emitted from the moderator are electrostatically extracted, focused and magnetically guided until they exit the reactor biological shield with 1-keV energy, approximately 3-cm beam diameter and an intensity exceeding 6x10{sup 8} positrons per second. A magnetic beam switch and transport system has been installed and tested that directs the beam into one of two spectrometers. The spectrometers are designed to implement state-of-the-art PALS and DBS techniques to perform positron and positronium annihilation studies of nanophases in matter.

  5. Design, construction, and procurement methodology of magnets for the 7-GeV Advanced Photon Source

    SciTech Connect (OSTI)

    Gorski, A.; Argyrakis, J.; Biggs, J. [and others

    1995-06-01T23:59:59.000Z

    All major magnets of the Advanced Photon Source (APS) have now been measured and installed in the facility. This paper describes the mechanical design, construction, and procurement philosophy and methodology, and lessons learned from the construction and procurement of more than 1500 magnets for the APS storage ring, injector synchrotron ring, and positron accumulator ring.

  6. GLAST SCIENCE GLOSSARY Source: http://glast.sonoma.edu/science/gru/glossary.html

    E-Print Network [OSTI]

    the nucleus. BATSE -- The Burst and Transient Source Experiment on board the Compton Gamma-ray Observatory. BATSE made all-sky observations of gamma-ray bursts and flares, as well as observing many other objects, the annihilation of an electron and positron results in the emission of two gamma-ray photons, each with an energy

  7. Mathematical modeling of positron emission tomography (PET) data to assess radiofluoride transport in living plants following petiolar administration

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Converse, Alexander K.; Ahlers, Elizabeth O.; Bryan, Tom W.; Hetue, Jackson D.; Lake, Katherine A.; Ellison, Paul A.; Engle, Jonathan W.; Barnhart, Todd E.; Nickles, Robert J.; Williams, Paul H.; et al

    2015-01-01T23:59:59.000Z

    Background: Ion transport is a fundamental physiological process that can be studied non-invasively in living plants with radiotracer imaging methods. Fluoride is a known phytotoxic pollutant and understanding its transport in plants after leaf absorption is of interest to those in agricultural areas near industrial sources of airborne fluoride. Here we report the novel use of a commercial, high-resolution, animal positron emission tomography (PET) scanner to trace a bolus of [¹?F]fluoride administered via bisected petioles of Brassica oleracea, an established model species, to simulate whole plant uptake of atmospheric fluoride. This methodology allows for the first time mathematical compartmental modelingmore »of fluoride transport in the living plant. Radiotracer kinetics in the stem were described with a single-parameter free- and trapped-compartment model and mean arrival times at different stem positions were calculated from the free-compartment time-activity curves. Results: After initiation of administration at the bisected leaf stalk, [¹?F] radioactivity climbed for approximately 10 minutes followed by rapid washout from the stem and equilibration within leaves. Kinetic modeling of transport in the stem yielded a trapping rate of 1.5 +/- 0.3%/min (mean +/- s.d., n = 3), velocity of 2.2 +/- 1.1 cm/min, and trapping fraction of 0.8 +/- 0.5%/cm. Conclusion: Quantitative assessment of physiologically meaningful transport parameters of fluoride in living plants is possible using standard positron emission tomography in combination with petiolar radiotracer administration. Movement of free fluoride was observed to be consistent with bulk flow in xylem, namely a rapid and linear change in position with respect to time. Trapping, likely in the apoplast, was observed. Future applications of the methods described here include studies of transport of other ions and molecules of interest in plant physiology.« less

  8. Enhancement models of momentum densities of annihilating electron-positron pairs: the many-body picture of natural geminals

    E-Print Network [OSTI]

    Ilja Makkonen; Mikko M. Ervasti; Topi Siro; Ari Harju

    2013-12-19T23:59:59.000Z

    The correlated motion of a positron surrounded by electrons is a fundamental many-body problem. We approach this by modeling the momentum density of annihilating electron-positron pairs using the framework of reduced density matrices, natural orbitals and natural geminals (electron-positron pair wave functions) of the quantum theory of many-particle systems. We find that an expression based on the natural geminals provides an exact, unique and compact expression for the momentum density. The natural geminals can be used to define and determine enhancement factors for enhancement models going beyond the independent-particle model for a better understanding of results of positron annihilation experiments.

  9. Coupled ion acoustic and drift waves in magnetized superthermal electron-positron-ion plasmas

    SciTech Connect (OSTI)

    Adnan, Muhammad; Qamar, Anisa [Institute of Physics and Electronics, University of Peshawar, Peshawar 25000 (Pakistan); National Center for Physics, Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Mahmood, S. [National Center for Physics, Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Theoretical Physics Division, PINSTECH P.O. Nilore Islamabad 44000 (Pakistan); Physics Institute, Federal University of Rio Grande do Sul (UFRGS), 915051-970, Porto Alegre, RS (Brazil)

    2014-09-15T23:59:59.000Z

    Linear and nonlinear coupled drift-ion acoustic waves are investigated in a nonuniform magnetoplasma having kappa distributed electrons and positrons. In the linear regime, the role of kappa distribution and positron content on the dispersion relation has been highlighted; it is found that strong superthermality (low value of ?) and addition of positrons lowers the phase velocity via decreasing the fundamental scalelengths of the plasmas. In the nonlinear regime, first, coherent nonlinear structure in the form of dipoles and monopoles are obtained and the boundary conditions (boundedness) in the context of superthermality and positron concentrations are discussed. Second, in case of scalar nonlinearity, a Korteweg–de Vries-type equation is obtained, which admit solitary wave solution. It is found that both compressive and rarefactive solitons are formed in the present model. The present work may be useful to understand the low frequency electrostatic modes in inhomogeneous electron positron ion plasmas, which exist in astrophysical plasma situations such as those found in the pulsar magnetosphere.

  10. A Gamma-Ray Burst/Pulsar for Cosmic-Ray Positrons with a Dark Matter-like Spectrum

    E-Print Network [OSTI]

    Kunihito Ioka

    2010-06-15T23:59:59.000Z

    We propose that a nearby gamma-ray burst (GRB) or GRB-like (old, single and short-lived) pulsar/supernova remnant/microquasar about 10^{5-6} years ago may be responsible for the excesses of cosmic-ray positrons and electrons recently observed by the PAMELA, ATIC/PPB-BETS, Fermi and HESS experiments. We can reproduce the smooth Fermi/HESS spectra as well as the spiky ATIC/PPB-BETS spectra. The spectra have a sharp cutoff that is similar to the dark matter predictions, sometimes together with a line (not similar), since higher energy cosmic-rays cool faster where the cutoff/line energy marks the source age. A GRB-like astrophysical source is expected to have a small but finite spread in the cutoff/line as well as anisotropy in the cosmic-ray and diffuse gamma-ray flux, providing a method for the Fermi and future CALET experiments to discriminate between dark matter and astrophysical origins.

  11. Low frequency electromagnetic oscillations in dense degenerate electron-positron pair plasma, with and without ions

    SciTech Connect (OSTI)

    Khan, S. A. [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Ayub, M. K. [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Pohang University of Science and Technology (POSTECH), Pohang, Gyunbuk 790-784 (Korea, Republic of); Ahmad, Ali [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 45320 (Pakistan); Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)

    2012-10-15T23:59:59.000Z

    Quantum plasma oscillations are studied in a strongly magnetized, ultra-dense plasma with degenerate electrons and positrons. The dispersive role of electron and positron quantum effects on low frequency (in comparison to electron cyclotron frequency) shear electromagnetic wave is investigated by employing hydrodynamic formulation. In the presence of ions, the density balance changes, and the electromagnetic wave (with frequency lower than the ion cyclotron frequency) is shown to couple with electrostatic ion mode under certain conditions. For such low frequency waves, it is also seen that the contribution of electron and positron degeneracy pressure is dominant as compared to their diffraction effects. The results are analyzed numerically for illustrative purpose pointing out their relevance to the dense laboratory (e.g., super-intense laser-dense matter interactions) and astrophysical plasmas.

  12. Perpendicular propagating electromagnetic envelope solitons in electron-positron-ion plasma

    SciTech Connect (OSTI)

    Jehan, Nusrat [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Salahuddin, M. [Pakistan Atomic Energy Commission, P.O. Box 1114, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Department of Physics, Theoretical Plasma Physics Group, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2010-05-15T23:59:59.000Z

    The nonlinear amplitude modulation of electromagnetic waves propagating perpendicular to the direction of ambient magnetic field in a uniform collisionless magnetized electron-positron-ion plasma is studied. The Krylov-Bogoliubov-Mitropolsky perturbation method is employed to derive nonlinear Schroedinger equation, which describes the amplitude dynamics of perturbed magnetic field. The modulation instability criterion reveals that the low frequency mode is always stable, whereas the high frequency mode becomes modulationally unstable for certain ranges of wave number and positron-to-electron density ratio. Furthermore, the positron-to-electron density ratio as well as the strength of ambient magnetic field is found to have significant effect on the solitary wave solutions of the nonlinear Schroedinger equation, namely, dark and bright envelope solitons.

  13. Ion acoustic shock waves in plasmas with warm ions and kappa distributed electrons and positrons

    SciTech Connect (OSTI)

    Hussain, S.; Mahmood, S.; Hafeez Ur-Rehman [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 44000, Pakistan and Department of Physics and Applied Mathematics, PIEAS, P.O. Nilore, Islamabad 44000 (Pakistan)] [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 44000, Pakistan and Department of Physics and Applied Mathematics, PIEAS, P.O. Nilore, Islamabad 44000 (Pakistan)

    2013-06-15T23:59:59.000Z

    The monotonic and oscillatory ion acoustic shock waves are investigated in electron-positron-ion plasmas (e-p-i) with warm ions (adiabatically heated) and nonthermal kappa distributed electrons and positrons. The dissipation effects are included in the model due to kinematic viscosity of the ions. Using reductive perturbation technique, the Kadomtsev-Petviashvili-Burgers (KPB) equation is derived containing dispersion, dissipation, and diffraction effects (due to perturbation in the transverse direction) in e-p-i plasmas. The analytical solution of KPB equation is obtained by employing tangent hyperbolic (Tanh) method. The analytical condition for the propagation of oscillatory and monotonic shock structures are also discussed in detail. The numerical results of two dimensional monotonic shock structures are obtained for graphical representation. The dependence of shock structures on positron equilibrium density, ion temperature, nonthermal spectral index kappa, and the kinematic viscosity of ions are also discussed.

  14. On a plasma having nonextensive electrons and positrons: Rogue and solitary wave propagation

    SciTech Connect (OSTI)

    El-Awady, E. I. [Department of Physics, Faculty of Science, Port Said University, Port Said (Egypt); Moslem, W. M. [Department of Physics, Faculty of Science, Port Said University, Port Said (Egypt); International Center for Advanced Studies in Physical Sciences, Faculty of Physics and Astronomy, Ruhr University Bochum, D-44780 Bochum (Germany)

    2011-08-15T23:59:59.000Z

    Generation of nonlinear ion-acoustic waves in a plasma having nonextensive electrons and positrons has been studied. Two wave modes existing in such plasma are considered, namely solitary and rogue waves. The reductive perturbation method is used to obtain a Korteweg-de Vries equation describing the system. The latter admits solitary wave pulses, while the dynamics of the modulationally unstable wave packets described by the Korteweg-de Vries equation gives rise to the formation of rogue excitation that is described by a nonlinear Schroedinger equation. The dependence of both solitary and rogue waves profiles on the nonextensive parameter, positron-to-ion concentration ratio, electron-to-positron temperature ratio, and ion-to-electron temperature ratio are investigated numerically. The results from this work are expected to contribute to the in-depth understanding of the nonlinear excitations that may appear in nonextensive astrophysical plasma environments, such as galactic clusters, interstellar medium, etc.

  15. Nonlinear ion-acoustic structures in dusty plasma with superthermal electrons and positrons

    SciTech Connect (OSTI)

    El-Tantawy, S. A. [Department of Physics, Faculty of Science, Port Said University, Port Said 42526 (Egypt); El-Bedwehy, N. A. [Department of Mathematics, Faculty of Science, Mansoura University, Damietta El-Gedida 34517 (Egypt); Moslem, W. M. [Department of Physics, Faculty of Science, Port Said University, Port Said 42526 (Egypt); International Center for Advanced Studies in Physical Science, Faculty of Physics, Astronomy, Ruhr University Bochum, D-44780 Bochum (Germany)

    2011-05-15T23:59:59.000Z

    Nonlinear ion-acoustic structures are investigated in an unmagnetized, four-component plasma consisting of warm ions, superthermal electrons and positrons, as well as stationary charged dust impurities. The basic set of fluid equations is reduced to modified Korteweg-de Vries equation. The latter admits both solitary waves and double layers solutions. Numerical calculations indicate that these nonlinear structures cannot exist for all physical parameters. Therefore, the existence regions for both solitary and double layers excitations have been defined precisely. Furthermore, the effects of temperature ratios of ions-to-electrons and electrons-to-positrons, positrons and dust concentrations, as well as superthermal parameters on the profiles of the nonlinear structures are investigated. Also, the acceleration and deceleration of plasma species have been highlight. It is emphasized that the present investigation may be helpful in better understanding of nonlinear structures which propagate in astrophysical environments, such as in interstellar medium.

  16. Head-on collision of ion-acoustic solitary waves in multicomponent plasmas with positrons

    SciTech Connect (OSTI)

    El-Shamy, E. F.; Sabry, R. [Department of Physics, Theoretical Physics Group, Faculty of Science, Mansoura University, Damietta-Branch, New Damietta 34517, Damietta (Egypt); Moslem, W. M. [Department of Physics, Faculty of Science, Port Said University, Port Said (Egypt); Shukla, P. K. [Institut fuer Theoretische Physik IV, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

    2010-08-15T23:59:59.000Z

    The head-on collision between two ion-acoustic solitary waves in an unmagnetized multicomponent plasma consisting of hot ions, hot positrons, and two-electron temperature distributions is investigated using the extended Poincare-Lighthill-Kuo method. The Kortwege-de Vries equations and the analytical phase shifts after the head-on collision of two solitary waves in this multicomponent plasma are obtained. The effects of two different types of isothermal electrons, the ratio of the hot ion temperature to the effective temperature, the ratio of the effective temperature to the positron temperature, the ratio of the number density of positrons to that of electrons species, and the physical processes (either isothermal or adiabatic) on the phase shifts are studied. It is found that these parameters can significantly influence the phase shifts of the solitons. The relevance of this investigation to space and laboratory plasmas is pointed out.

  17. ENHANCEMENT OF THE POSITRON INTENSITY BY A TUNGSTEN SINGLE-CRYSTAL TARGET AT THE KEKB INJECTOR LINAC

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    by these stimulating results, we proceeded to systematic studies on the positron-production efficiencies with tungstenENHANCEMENT OF THE POSITRON INTENSITY BY A TUNGSTEN SINGLE-CRYSTAL TARGET AT THE KEKB INJECTOR, Russia R. Chehab, IPNL, IN2P3-CNRS, Universite Claude Bernald 1, France Abstract A new tungsten single

  18. Size of nanoobjects in oil and gas species and materials with positron annihilation spectroscopy

    E-Print Network [OSTI]

    Grafutin, V I; Elnikova, L V

    2012-01-01T23:59:59.000Z

    The analytical method to determine geometry and size of nano-scale defects in oil and gas species and materials is proposed. The modeling is carried out with the parameters of the positron spectra in the angular distribution method of positron annihilation spectroscopy, and is based on the 'free electron' approximation. From the annihilation decay kinetics, it is possible to express the trapping velocity of parapositronium in pores via intensities of the positronium components and to define the concentration and radii of pores in a porous layer. As the result, size and the concentration of micro-porous cylindrical nano-objects in the silicon samples are estimated.

  19. Manipulation of the magnetron orbit of a positron cloud in a Penning trap

    SciTech Connect (OSTI)

    Mortensen, T.; Deller, A.; Isaac, C. A.; Werf, D. P. van der; Charlton, M. [Department of Physics, College of Science, Swansea University, Singleton Park, Swansea SA2 8PP (United Kingdom); Machacek, J. R. [Centre for Matter-Antimatter Studies, Physics Laboratories, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

    2013-01-15T23:59:59.000Z

    We describe a simple and versatile method to manipulate the amplitude of the magnetron orbit of ions stored in a Penning trap, applied here to a cloud of low energy positrons. By applying a pulsed voltage to a split electrode in the trap, which is normally used for rotating wall compression of the particles, the size of the magnetron orbit can be changed at will. The modified orbit has been shown to be stable for many magnetron periods. The technique could find use in applications which require off-axis ejection of particles, for instance in the filling of arrays of traps for multicell positron storage.

  20. Leptophilic Dark Matter and AMS-02 Cosmic-ray Positron Flux

    E-Print Network [OSTI]

    Qing-Hong Cao; Chuan-Ren Chen; Ti Gong

    2014-09-25T23:59:59.000Z

    With the measurement of positron flux published recently by AMS-02 collaboration, we show how the leptophilic dark matter fits the observation. We obtain the percentages of different products of dark matter annihilation that can best describe the flux of high energy positrons observed by AMS. We show that dark matter annihilates predominantly into $\\tau\\tau$ pair, while both $ee$ and $\\mu\\mu$ final states should be less than $20\\%$. When gauge boson final states are included, the best branching ratio of needed $\\tau\\tau$ mode reduces.

  1. Application of exterior complex scaling to positron-hydrogencollisions including rearrangement

    SciTech Connect (OSTI)

    Bartlett, Philip L.; Stelbovics, Andris T.; Rescigno, Thomas N.; McCurdy, C. William

    2007-12-06T23:59:59.000Z

    The first application of an exterior complex scaling method to an atomic scattering problem with distinct rearrangement channels is reported. Calculations are performed for positron-hydrogen collisions in an s-wave model employing an electron-positron potential of V{sub 12} = -(8+(r{sub 1}-r{sub 2}){sup 2}){sup 1/2}, using the time-independent propagating exterior complex scaling (PECS) method. This potential has the correct long-range Coulomb tail of the full problem and the results demonstrate that ECS-based methods can accurately calculate scattering, ionization and positronium formation cross sections in this three-body rearrangement collision.

  2. Systematics associated with positronium fractions as measured with variable-energy positron beams

    SciTech Connect (OSTI)

    Schultz, P.J.; Lynn, K.G.; Jorch, H.H.

    1984-11-01T23:59:59.000Z

    Positronium fraction measurements using positron beams have been utilized to extract information about the diffusion properties of positrons as well as defect concentrations in the near surface region of materials under a variety of experimental conditions. Owing to this recent interest we have undertaken to study some of the systematics and uncertainties associated with measurements of the positronium fraction, f. We restrict our discussion to determinations of f based on the peak:total ratio of counting rates for a single detector, only briefly considering alternate ways of obtaining f. We conclude with several recommendations that should be of particular interest to practitioners in the field.

  3. On the fully nonlinear acoustic waves in a plasma with positrons beam impact and superthermal electrons

    SciTech Connect (OSTI)

    Ali Shan, S. [Theoretical Plasma Physics Division, PINSTECH, Nilore, 44000 Islamabad (Pakistan) [Theoretical Plasma Physics Division, PINSTECH, Nilore, 44000 Islamabad (Pakistan); National Centre For Physics (NCP), Shahdra Valley Road, 44000 Islamabad (Pakistan); Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad (Pakistan); El-Tantawy, S. A.; Moslem, W. M. [Department of Physics, Faculty of Science, Port Said University, Port Said 42521 (Egypt)] [Department of Physics, Faculty of Science, Port Said University, Port Said 42521 (Egypt)

    2013-08-15T23:59:59.000Z

    Arbitrary amplitude ion-acoustic waves in an unmagnetized plasma consisting of cold positive ions, superthermal electrons, and positrons beam are reported. The basic set of fluid equations is reduced to an energy-balance like equation. The latter is numerically analyzed to examine the existence regions for solitary and shock waves. It is found that only solitary waves can propagate, however, the model cannot support shocks. The effects of superthermality and beam parameters (via, positrons concentration and streaming velocity) on the existence region, as well as solitary wave profile have been discussed.

  4. Ion-acoustic cnoidal waves in plasmas with warm ions and kappa distributed electrons and positrons

    SciTech Connect (OSTI)

    Kaladze, T. [Department of Physics, Government College University (GCU), Lahore 54000 (Pakistan) [Department of Physics, Government College University (GCU), Lahore 54000 (Pakistan); I.Vekua Institute of Applied Mathematics, Tbilisi State University, 0186 Georgia (United States); Mahmood, S., E-mail: shahzadm100@gmail.com [Theoretical Physics Division (TPD), PINSTECH P.O. Nilore Islamabad 44000 (Pakistan); National Center for Physics (NCP), Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan)

    2014-03-15T23:59:59.000Z

    Electrostatic ion-acoustic periodic (cnoidal) waves and solitons in unmagnetized electron-positron-ion (EPI) plasmas with warm ions and kappa distributed electrons and positrons are investigated. Using the reductive perturbation method, the Korteweg-de Vries (KdV) equation is derived with appropriate boundary conditions for periodic waves. The corresponding analytical and various numerical solutions are presented with Sagdeev potential approach. Differences between the results caused by the kappa and Maxwell distributions are emphasized. It is revealed that only hump (compressive) structures of the cnoidal waves and solitons are formed. It is shown that amplitudes of the cnoidal waves and solitons are reduced in an EPI plasma case in comparison with the ordinary electron-ion plasmas. The effects caused by the temperature variations of the warm ions are also discussed. It is obtained that the amplitude of the cnoidal waves and solitons decreases for a kappa distributed (nonthermal) electrons and positrons plasma case in comparison with the Maxwellian distributed (thermal) electrons and positrons EPI plasmas. The existence of kappa distributed particles leads to decreasing of ion-acoustic frequency up to thermal ions frequency.

  5. Solitons and shocks in dense astrophysical magnetoplasmas with relativistic degenerate electrons and positrons

    SciTech Connect (OSTI)

    Ali, S. [National Centre for Physics at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan)] [National Centre for Physics at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Ata-ur-Rahman [National Centre for Physics at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan) [National Centre for Physics at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Institute of Physics and Electronics, University of Peshawar, Peshawar 25000 (Pakistan)

    2014-04-15T23:59:59.000Z

    The linear and nonlinear properties of the ion-acoustic (IA) waves are investigated in a relativistically degenerate magnetoplasma, whose constituents are the electrons, positrons, and ions. The electrons and positrons are assumed to obey the Fermi-Dirac statistics, whereas the cold ions are taken to be inertial and magnetized. In linear analysis, various limiting cases are discussed both analytically and numerically. However, for nonlinear studies, the well-known reductive perturbation technique is employed to derive the Zakharov-Kuznetsov and Zakharov-Kuznetsov Burgers equations in the presence of relativistically degenerate electrons and positrons. Furthermore, with the use of hyperbolic tangent method, the equations are simplified to admit the soliton and shock wave solutions. Numerically, it is shown that the amplitude, width, and phase speed associated with the localized IA solitons and shocks are significantly influenced by the various intrinsic plasma parameters relevant to our model. The present analysis can be useful for understanding the collective processes in dense astrophysical environments like neutron stars, where the electrons and positrons are expected to be relativistic and degenerate.

  6. Brain imaging methods used in experimental brain research such as Positron Emission Tomography (PET) and Functional

    E-Print Network [OSTI]

    Mueller, Klaus

    ABSTRACT Brain imaging methods used in experimental brain research such as Positron Emission and are best understood in the context of the underlying 3D brain anatomy. In this paper, we present a novel Brain Mapping, Functional Imaging 1 INTRODUCTION Although the human brain is no longer the black box

  7. Brain imaging methods used in experimental brain research such as Positron Emission Tomography (PET) and Functional

    E-Print Network [OSTI]

    Mueller, Klaus

    ABSTRACT Brain imaging methods used in experimental brain research such as Positron Emission of methods create statistical parametric maps (SPMs) of the brain on a voxel- basis. In our approach, they are best understood in the context of the underly- ing 3-D brain anatomy. However, despite the power

  8. PLASMA FOCUSING OF HIGH ENERGY DENSITY ELECTRON AND POSITRON BEAMS \\Lambda

    E-Print Network [OSTI]

    PLASMA FOCUSING OF HIGH ENERGY DENSITY ELECTRON AND POSITRON BEAMS \\Lambda J.S.T. Ng, P. Chen, W present results from the SLAC E­150 experiment on plasma focusing of high energy density electron and of the SLAC E­150 experiment are to study plasma focusing for high energy, high density par­ ticle beams

  9. Wavelet based multiresolution expectation maximization image reconstruction algorithm for positron emission tomography

    E-Print Network [OSTI]

    Raheja, Amar

    Wavelet based multiresolution expectation maximization image reconstruction algorithm for positron. This work transforms the MGEM and MREM algorithm to a Wavelet based Multiresolution EM (WMREM) algorithm by performing a 2D-wavelet transform on the acquired tube data that is used to reconstruct images at different

  10. Particle Acceleration Zones Above Pulsar Polar Caps: Electron and Positron Pair Formation Fronts

    E-Print Network [OSTI]

    Alice K. Harding; Alexander G. Muslimov

    1998-05-11T23:59:59.000Z

    We investigate self-consistent particle acceleration near a pulsar polar cap (PC) by the electrostatic field due to the effect of inertial frame dragging. Test particles gain energy from the electric field parallel to the open magnetic field lines and lose energy by both curvature radiation (CR) and resonant and non-resonant inverse Compton scattering (ICS) with soft thermal X-rays from the neutron star (NS) surface. Gamma-rays radiated by electrons accelerated from the stellar surface produce pairs in the strong magnetic field, which screen the electric field beyond a pair formation front (PFF). Some of the created positrons can be accelerated back toward the surface and produce gamma-rays and pairs that create another PFF above the surface. We find that ICS photons control PFF formation near the surface, but due to the different angles at which the electron and positron scatter the soft photons, positron initiated cascades develop above the surface and screen the accelerating electric field. Stable acceleration from the NS surface is therefore not possible in the presence of dominant ICS energy losses. However, we find that stable acceleration zones may occur at some distance above the surface, where CR dominates the electron and positron energy losses, and there is up-down symmetry between the electron and positron PFFs. We examine the dependence of CR-controlled acceleration zone voltage, width and height above the surface on parameters of the pulsar and its soft X-ray emission. For most pulsars, we find that acceleration will start at a height of 0.5 - 1 stellar radii above the NS surface.

  11. Advanced RF power sources for linacs

    SciTech Connect (OSTI)

    Wilson, P.B.

    1996-10-01T23:59:59.000Z

    In order to maintain a reasonable over-all length at high center-of-mass energy, the main linac of an electron-positron linear collider must operate at a high accelerating gradient. For copper (non-superconducting) accelerator structures, this implies a high peak power per unit length and a high peak power per RF source, assuming a limited number of discrete sources are used. To provide this power, a number of devices are currently under active development or conceptual consideration: conventional klystrons with multi-cavity output structures, gyroklystrons, magnicons, sheet-beam klystrons, multiple-beam klystrons and amplifiers based on the FEL principle. To enhance the peak power produced by an rf source, the SLED rf pulse compression scheme is currently in use on existing linacs, and new compression methods that produce a flatter output pulse are being considered for future linear colliders. This paper covers the present status and future outlook for the more important rf power sources and pulse compression systems. It should be noted that high gradient electron linacs have applications in addition to high-energy linear colliders; they can, for example, serve as compact injectors for FEL`s and storage rings.

  12. Multi-dimensional instability of obliquely propagating ion acoustic solitary waves in electron-positron-ion superthermal magnetoplasmas

    SciTech Connect (OSTI)

    EL-Shamy, E. F., E-mail: emadel-shamy@hotmail.com [Department of Physics, Faculty of Science, Damietta University, New Damietta 34517, Egypt and Department of Physics, College of Science, King Khalid University, Abha P.O. 9004 (Saudi Arabia)

    2014-08-15T23:59:59.000Z

    The solitary structures of multi–dimensional ion-acoustic solitary waves (IASWs) have been considered in magnetoplasmas consisting of electron-positron-ion with high-energy (superthermal) electrons and positrons are investigated. Using a reductive perturbation method, a nonlinear Zakharov-Kuznetsov equation is derived. The multi-dimensional instability of obliquely propagating (with respect to the external magnetic field) IASWs has been studied by the small-k (long wavelength plane wave) expansion perturbation method. The instability condition and the growth rate of the instability have been derived. It is shown that the instability criterion and their growth rate depend on the parameter measuring the superthermality, the ion gyrofrequency, the unperturbed positrons-to-ions density ratio, the direction cosine, and the ion-to-electron temperature ratio. Clearly, the study of our model under consideration is helpful for explaining the propagation and the instability of IASWs in space observations of magnetoplasmas with superthermal electrons and positrons.

  13. Positron emission imaging device and method of using the same

    DOE Patents [OSTI]

    Bingham, Philip R.; Mullens, James Allen

    2013-01-15T23:59:59.000Z

    An imaging system and method of imaging are disclosed. The imaging system can include an external radiation source producing pairs of substantially simultaneous radiation emissions of a picturization emission and a verification emissions at an emission angle. The imaging system can also include a plurality of picturization sensors and at least one verification sensor for detecting the picturization and verification emissions, respectively. The imaging system also includes an object stage is arranged such that a picturization emission can pass through an object supported on said object stage before being detected by one of said plurality of picturization sensors. A coincidence system and a reconstruction system can also be included. The coincidence can receive information from the picturization and verification sensors and determine whether a detected picturization emission is direct radiation or scattered radiation. The reconstruction system can produce a multi-dimensional representation of an object imaged with the imaging system.

  14. Electrostatic drift shocks and drift wave instability in inhomogeneous rotating electron-positron-ion plasmas

    SciTech Connect (OSTI)

    Haque, Q. [Theoretical Plasma Physics Division, PINSTECH P. O. Nilore, Islamabad (Pakistan) and National Centre for Physics, Islamabad (Pakistan)

    2012-09-15T23:59:59.000Z

    The electrostatic drift wave shocks are studied in inhomogeneous rotating e-p-i plasma of the pulsar atmosphere. In this regard, the dissipation due to ion-neutral collisions is considered, which facilitate the formation of shock structures. It is noticed that these structures can move with the velocity of the drift wave which is not possible without considering the rotational effects. Several limiting cases are also discussed. In addition, the drift wave instability is obtained when electrons and positrons could not cancel out the space charge effects along the magnetic field lines in the presence of electron-ion and positron-ion collisions. Further, it is found that this instability is sensitive to rotational frequency of the object. The importance of the results with relevance to astrophysical plasmas is also pointed out.

  15. Nonlinear screening effect in an ultrarelativistic degenerate electron-positron gas

    SciTech Connect (OSTI)

    Tsintsadze, N. L. [Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Department of Physics, Government College University, Lahore 54000 (Pakistan); Rasheed, A.; Shah, H. A. [Department of Physics, Government College University, Lahore 54000 (Pakistan); Murtaza, G. [Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan)

    2009-11-15T23:59:59.000Z

    Nonlinear screening process in an ultrarelativistic degenerate electron-positron gas has been investigated by deriving a generalized nonlinear Poisson equation for the electrostatic potential. In the simple one-dimensional case, the nonlinear Poisson equation leads to Debye-like (Coulomb-like) solutions at distances larger (less) than the characteristic length. When the electrostatic energy is larger than the thermal energy, this nonlinear Poisson equation converts into the relativistic Thomas-Fermi equation whose asymptotic solution in three dimensions shows that the potential field goes to zero at infinity much more slowly than the Debye potential. The possibility of the formation of a bound state in electron-positron plasma is also indicated. Further, it is investigated that the strong spatial fluctuations of the potential field may reduce the screening length and that the root mean square of this spatial fluctuating potential goes to zero for large r rather slowly as compared to the case of the Debye potential.

  16. Planar and nonplanar ion acoustic shock waves in relativistic degenerate astrophysical electron-positron-ion plasmas

    SciTech Connect (OSTI)

    Ata-ur-Rahman,; Qamar, A. [Institute of Physics and Electronics, University of Peshawar, Peshawar 25000 (Pakistan); National Centre for Physics, QAU Campus, Shahdrah Valley Road, Islamabad 44000 (Pakistan); Ali, S. [National Centre for Physics, QAU Campus, Shahdrah Valley Road, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Physics Department, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2013-04-15T23:59:59.000Z

    We have studied the propagation of ion acoustic shock waves involving planar and non-planar geometries in an unmagnetized plasma, whose constituents are non-degenerate ultra-cold ions, relativistically degenerate electrons, and positrons. By using the reductive perturbation technique, Korteweg-deVries Burger and modified Korteweg-deVries Burger equations are derived. It is shown that only compressive shock waves can propagate in such a plasma system. The effects of geometry, the ion kinematic viscosity, and the positron concentration are examined on the ion acoustic shock potential and electric field profiles. It is found that the properties of ion acoustic shock waves in a non-planar geometry significantly differ from those in planar geometry. The present study has relevance to the dense plasmas, produced in laboratory (e.g., super-intense laser-dense matter experiments) and in dense astrophysical objects.

  17. Large amplitude dust-acoustic solitary waves in electron-positron-ion plasma with dust grains

    SciTech Connect (OSTI)

    Esfandyari-Kalejahi, A.; Afsari-Ghazi, M.; Noori, K.; Irani, S. [Department of Physics, Faculty of Science, Azarbaijan University of Shahid Madani, 51745-406, Tabriz (Iran, Islamic Republic of)

    2012-08-15T23:59:59.000Z

    Propagation of large amplitude dust-acoustic (DA) solitary waves is investigated in electron-positron-ion plasmas in the presence of dust grains using Sagdeev potential method. It is shown that acceptable values of Mach number for propagation of the large amplitude DA solitary waves depend strongly on plasma parameters. It is also observed that the amplitude of DA solitary waves increases as both the Mach number M and dust charge Z{sub d} are increased. Furthermore, it is found that a dusty plasma with inertial dust fluid and Boltzmann distributed electrons, positrons, and ions admits only negative solitary potentials associated with nonlinear dust-acoustic waves. In addition, it is remarked that the formation of double layers is not possible in this plasma system.

  18. Nonlinear interaction of intense electromagnetic waves with a magnetoactive electron-positron-ion plasma

    SciTech Connect (OSTI)

    Khorashadizadeh, S. M.; Rastbood, E.; Zeinaddini Meymand, H. [Physics Department, University of Birjand, Birjand (Iran, Islamic Republic of)] [Physics Department, University of Birjand, Birjand (Iran, Islamic Republic of); Niknam, A. R. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of)] [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of)

    2013-08-15T23:59:59.000Z

    The nonlinear coupling between circularly polarized electromagnetic (CPEM) waves and acoustic-like waves in a magnetoactive electron-positron-ion (e-p-i) plasma is studied, taking into account the relativistic motion of electrons and positrons. The possibility of modulational instability and its growth rate as well as the envelope soliton formation and its characteristics in such plasmas are investigated. It is found that the growth rate of modulation instability increases in the case that ?{sub c}/?<1 (?{sub c} and ? are the electron gyrofrequency and the CPEM wave frequency, respectively) and decreases in the case that ?{sub c}/?>1. It is also shown that in a magnetoactive e-p-i plasma, the width of bright soliton increases/decreases in case of (?{sub c}/?)<1/(?{sub c}/?)>1 by increasing the magnetic field strength.

  19. Photon emission by ultra-relativistic positrons in crystalline undulators: the high-energy regime

    E-Print Network [OSTI]

    Krause, W; Solov'yov, A V; Greiner, W

    2015-01-01T23:59:59.000Z

    This paper discusses the undulator radiation emitted by high-energy positrons during planar channeling in periodically bent crystals. We demonstrate that the construction of the undulator for positrons with energies of 10 GeV and above is only possible if one takes into account the radiative energy losses. The frequency of the undulator radiation depends on the energy of the particle. Thus the decrease of the particle's energy during the passage of the crystal should result in the destruction of the undulator radiation regime. However, we demonstrate that it is possible to avoid the destructive influence of the radiative losses on the frequency of the undulator radiation by the appropriate variation of the shape of the crystal channels. We also discuss a method by which, to our mind, it would be possible to prepare the crystal with the desired properties of its channels.

  20. The intense slow positron beam facility at the PULSTAR reactor and applications in nano-materials study

    SciTech Connect (OSTI)

    Liu, Ming; Moxom, Jeremy; Hawari, Ayman I. [Nuclear Reactor Program, Department of Nuclear Engineering, North Carolina State University, P.O. Box 7909, Raleigh, NC 27695 (United States); Gidley, David W. [Department of Physics, University of Michigan, 450 Church Street, Ann Arbor MI 48109 (United States)

    2013-04-19T23:59:59.000Z

    An intense slow positron beam has been established at the PULSTAR nuclear research reactor of North Carolina State University. The slow positrons are generated by pair production in a tungsten moderator from gammarays produced in the reactor core and by neutron capture reactions in cadmium. The moderated positrons are electrostatically extracted and magnetically guided out of the region near the core. Subsequently, the positrons are used in two spectrometers that are capable of performing positron annihilation lifetime spectroscopy (PALS) and positron Doppler broadening spectroscopy (DBS) to probe the defect and free volume properties of materials. One of the spectrometers (e{sup +}-PALS) utilizes an rf buncher to produce a pulsed beam and has a timing resolution of 277 ps. The second spectrometer (Ps-PALS) uses a secondary electron timing technique and is dedicated to positronium lifetime measurements with an approximately 1 ns timing resolution. PALS measurements have been conducted in the e{sup +}-PALS spectrometer on a series of nano-materials including organic photovoltaic thin films, membranes for filtration, and polymeric fibers. These studies have resulted in understanding some critical issues related to the development of the examined nano-materials.

  1. Hadron Formation in Deep-Inelastic Positron Scattering in a Nuclear Environment

    E-Print Network [OSTI]

    Airapetian, A; Akushevich, I V; Amarian, M; Arrington, J; Aschenauer, E C; Avakian, H; Avakian, R; Avetisian, A; Avetissian, E; Bailey, P; Bains, B; Baumgarten, C; Beckmann, M; Belostotskii, S; Bernreuther, S; Bianchi, N; Böttcher, Helmut B; Borisov, A; Bouwhuis, M; Brack, J; Brauksiepe, S; Braun, B; Brückner, W; Brüll, A; Budz, P; Bulten, H J; Capitani, G P; Carter, P; Chumney, P; Cisbani, E; Court, G R; Dalpiaz, P F; De Leo, R; De Nardo, L; De Sanctis, E; De Schepper, D; Devitsin, E G; De Witt-Huberts, P K A; Di Nezza, P; Dzhordzhadze, V; Düren, M; Dvoredsky, A P; Elbakian, G M; Ely, J; Fantoni, A; Feshchenko, A; Felawka, L; Ferro-Luzzi, M; Fiedler, K; Filippone, B W; Fischer, H; Fox, B; Franz, J; Frullani, S; Gärber, Y; Garibaldi, F; Garutti, E; Gavrilov, G E; Karibian, V; Golendukhin, A; Graw, G; Grebenyuk, O; Green, P W; Greeniaus, L G; Gute, A; Haeberli, W; Hartig, M; Hasch, D; Heesbeen, D; Heinsius, F H; Henoch, M; Hertenberger, R; Hesselink, W H A; Hofman, G J; Holler, Y; Holt, R J; Hommez, B; Iarygin, G; Iodice, M; Izotov, A A; Jackson, H E; Jgoun, A; Jung, P; Kaiser, R; Kanesaka, J; Kinney, E R; Kiselev, A; Kitching, P; Kobayashi, H; Koch, N; Königsmann, K C; Kolster, H; Korotkov, V A; Kotik, E; Kozlov, V; Krivokhizhin, V G; Kyle, G S; Lagamba, L; Laziev, A; Lenisa, P; Lindemann, T; Lorenzon, W; Makins, N C R; Martin, J W; Marukyan, H O; Masoli, F; McAndrew, M; McIlhany, K; McKeown, R D; Meissner, F; Menden, F; Metz, A; Meyners, N; Miklukho, O; Miller, C A; Milner, R; Muccifora, V; Mussa, R; Nagaitsev, A P; Nappi, E; Naryshkin, Yu; Nass, A; Negodaeva, K; Nowak, Wolf-Dieter; Oganesyan, K A; O'Neill, T G; Openshaw, R; Ouyang, J; Owen, B R; Pate, S F; Potashov, S Yu; Potterveld, D H; Rakness, G; Rappoport, V; Redwine, R P; Reggiani, D; Reolon, A R; Ristinen, R; Rith, K; Robinson, D; Rostomyan, A; Ruh, M; Ryckbosch, D; Sakemi, Y; Sato, T; Savin, I A; Scarlett, C; Schäfer, A; Schill, C; Schmidt, F; Schnell, G; Schüler, K P; Schwind, A; Seibert, J; Seitz, B; Shibata, T A; Shin, T; Shutov, V B; Simani, M C; Simon, A; Sinram, K; Steffens, E; Steijger, J J M; Stewart, J; Stösslein, U; Suetsugu, K; Sutter, M F; Taroian, S P; Terkulov, A R; Tessarin, S; Thomas, E; Tipton, B; Tytgat, M; Urciuoli, G M; Van den Brand, J F J; van der Steenhoven, G; Van de Vyver, R; Van Hunen, J J; Vetterli, Martin C; Vikhrov, V V; Vincter, M G; Visser, J; Volk, E; Weiskopf, C; Wendland, J; Wilbert, J; Wise, T; Yen, S; Yoneyama, S; Zohrabyan, H G

    2001-01-01T23:59:59.000Z

    The influence of the nuclear medium on the production of charged hadrons in semi-inclusive deep-inelastic scattering has been studied by the HERMES experiment at DESY using a 27.5 GeV positron beam. The differential multiplicity of charged hadrons and identified charged pions from nitrogen relative to that from deuterium has been measured as a function of the virtual photon energy \

  2. Observation of Magnetic Resonances in Electron Clouds in a Positron Storage Ring

    SciTech Connect (OSTI)

    Pivi, M.T.F.; Ng, J.S.T.; Cooper, F.; Kharakh, D.; King, F.; Kirby, R.E.; Kuekan, B.; Spencer, Cherrill M.; Raubenheimer, T.O.; Wang, L.F.; /SLAC

    2011-08-24T23:59:59.000Z

    The first experimental observation of magnetic resonances in electron clouds is reported. The resonance was observed as a modulation in cloud intensity for uncoated as well as TiN-coated aluminum surfaces in the positron storage ring of the PEP-II collider at SLAC. Electron clouds frequently arise in accelerators of positively charged particles, and severely impact the machines performance. The TiN coating was found to be an effective remedy, reducing the cloud intensity by three orders of magnitude.

  3. Electron-Positron Pair Production in Space- or Time-Dependent Electric Fields

    E-Print Network [OSTI]

    Hagen Kleinert; Remo Ruffini; She-Sheng Xue

    2008-07-06T23:59:59.000Z

    Treating the production of electron and positron pairs by a strong electric field from the vacuum as a quantum tunneling process we derive, in semiclassical approximation, a general expression for the pair production rate in a $z$-dependent electric field $E(z)$ pointing in the $z$-direction. We also allow for a smoothly varying magnetic field parallel to $E(z)$. The result is applied to a confined field $E(z)\

  4. Electron-Positron Pair Production by an Electron in a Magnetic Field Near the Process Threshold

    E-Print Network [OSTI]

    O. P. Novak; R. I. Kholodov; P. I. Fomin

    2011-01-13T23:59:59.000Z

    The electron-positron pair production by an electron in a strong magnetic field near the process threshold is considered. The process is shown to be more probable if the spin of the initial electron is oriented along the field. In this case, the probability of the process is $\\sim10^{13} s^{-1}$ when the magnetic field strength is $H=4\\cdot 10^{12}$ G.

  5. Positron annihilation studies of fluorine-vacancy complexes in Si and SiGe

    SciTech Connect (OSTI)

    Edwardson, C. J.; Coleman, P. G. [Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom); El Mubarek, H. A. W.; Gandy, A. S. [School of Electrical and Electronic Engineering, University of Manchester, Manchester, M13 9PL (United Kingdom)

    2012-04-01T23:59:59.000Z

    The formation of fluorine-vacancy (FV) complexes in strained Si-SiGe-Si multilayer structures and relaxed SiGe layers of varying Ge content has been investigated using variable-energy positron annihilation spectroscopy, including Doppler-broadened spectra ratio curves. It has been found that in all sample types there are two distinct regions defined only by the damage created by the implanted F ions. The first, shallower region (from the surface to a depth of {approx}200 nm) was found to contain a mixture of undecorated vacancies and FV complexes; there is no correlation between the vacancy or F concentration in this region and the Ge content. The multi-layer samples may also have O contamination that is not present in the relaxed samples. The second region (at depths {approx}200-440 nm) contains primarily FV complexes in all samples. In the multi-layer samples secondary ion mass spectrometry (SIMS) results show peaks of F accumulating in, or at the interfaces of, each SiGe multi-layer; the FV complexes, however, are distributed over depths similar to those in the relaxed samples, with some localization at the SiGe layer located within the second region. The positron response is primarily to FV complexes formed by the F implant in all samples. The F: FV ratios are approximately 3-7: 1 in the relaxed samples. Positrons appear to be relatively insensitive to the largest of the F SIMS peaks which lies beyond the second region. This is probably because the F has filled all the open volume at the SiGe layer, leaving no positron trapping sites.

  6. Extragalactic Inverse Compton Light from Dark Matter annihilation and the Pamela positron excess

    SciTech Connect (OSTI)

    Profumo, Stefano [Department of Physics, University of California, 1156 High St, Santa Cruz, CA 95064 (United States); Jeltema, Tesla E., E-mail: profumo@scipp.ucsc.edu, E-mail: tesla@ucolick.org [UCO/Lick Observatories, 1156 High St, Santa Cruz, CA 95064 (United States)

    2009-07-01T23:59:59.000Z

    We calculate the extragalactic diffuse emission originating from the up-scattering of cosmic microwave photons by energetic electrons and positrons produced in particle dark matter annihilation events at all redshifts and in all halos. We outline the observational constraints on this emission and we study its dependence on both the particle dark matter model (including the particle mass and its dominant annihilation final state) and on assumptions on structure formation and on the density profile of halos. We find that for low-mass dark matter models, data in the X-ray band provide the most stringent constraints, while the gamma-ray energy range probes models featuring large masses and pair-annihilation rates, and a hard spectrum for the injected electrons and positrons. Specifically, we point out that the all-redshift, all-halo inverse Compton emission from many dark matter models that might provide an explanation to the anomalous positron fraction measured by the Pamela payload severely overproduces the observed extragalactic gamma-ray background.

  7. Modulation instability of low-frequency electrostatic ion waves in magnetized electron-positron-ion plasma

    SciTech Connect (OSTI)

    Jehan, Nusrat [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Pakistan Atomic Energy Commission, P. O. Box 1114, Islamabad 44000 (Pakistan); Salahuddin, M. [Pakistan Atomic Energy Commission, P. O. Box 1114, Islamabad 44000 (Pakistan); Saleem, H. [PINSTECH (NPD), P. O. Nilore, Islamabad (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2008-09-15T23:59:59.000Z

    The nonlinear amplitude modulation of low-frequency electrostatic ion waves propagating in collisionless magnetized electron-positron-ion plasma are studied. The Krylov-Bogoliubov-Mitropolsky perturbation method is employed to derive the nonlinear Schroedinger equation. Modulation instability of both ion-acoustic and ion-cyclotronlike modes is examined. We found that the ion-acoustic mode, which propagates below the ion-cyclotron frequency, is stable if the strength of the external magnetic field is small. However, as the strength of the magnetic field increases, this mode becomes modulationally unstable for a range of wave numbers and angles of propagation. This range increases as the strength of the magnetic field and/or positron density increases. For the ion-cyclotronlike mode, which propagates above the ion-cyclotron frequency, a number of stability/instability regions appear in the (k{sub c},{theta}) plane even for a very small value of the magnetic field. It is found that, for both modes, critical wave number k{sub c} separating the stability and instability regions, shifts towards higher values as the density of the positron increases.

  8. Feasibility of cooling positrons via conduction in conductive micro-tubes

    SciTech Connect (OSTI)

    Khamehchi, M. A., E-mail: mak@cmr.wsu.edu; Baker, C. J.; Weber, M. H.; Lynn, K. G., E-mail: kgl@wsu.edu [Center for Materials Research, Washington State University, Pullman, Washington 99164-2814 (United States)

    2014-01-15T23:59:59.000Z

    A first order perturbation with respect to velocity has been employed to find the frictional damping force imposed on a single moving charge inside a conductive cylindrical micro-tube. The tensorial relationship between the force and velocity is derived and numerically estimated. Our results asymptotically match that of a flat geometry presented in the literature. Using the single particle analysis the cooling is formulated for an arbitrary density ensemble. It is shown that no further cooling via conduction occurs in the well-established non-neutral plasma equilibrium state. Also, the cooling rate for a weakly interacting ensemble is estimated. It is shown micro-tubes can be employed to cool down low density positron ensembles and/or to improve the beam emittance. A pack of tens of thousands of individual micro-tubes, each cooling only tens of positrons, is capable of cooling hundreds of thousands of particles in each cooling cycle. For example, with tens of particles per micro-tube in a 5?cm long micro-tube stack with the resistivity of 0.46??m and the tubes of radius 50??m, hundreds of thousands of positrons can be cooled down with a time constant of 103??s in longitudinal and 7??s in perpendicular direction. However, it must be noted that the cooling does not guarantee long term storage of particles in micro-tubes.

  9. Total cross sections for positron scattering from benzene, cyclohexane, and aniline

    SciTech Connect (OSTI)

    Zecca, Antonio; Moser, Norberto; Perazzolli, Chiara; Salemi, Alessandro [Department of Physics, University of Trento, I-38050 Povo (Trento) (Italy); Brunger, Michael J. [ARC Centre for Antimatter-Matter Studies, School of Chemistry, Physics and Earth Sciences, Flinders University, G.P.O. Box 2100, Adelaide, South Australia 5001 (Australia)

    2007-08-15T23:59:59.000Z

    We use a linear transmission technique to measure total cross sections for positron scattering from benzene, cyclohexane, and aniline. In the case of cyclohexane, the energy range of the present study is 0.1-20 eV, while for benzene and aniline it is 0.2-20 eV. With respect to benzene and cyclohexane, comparison is made to the only other existing results we know of [Makochekanwa and co-workers, Phys. Rev. A 68, 032707 (2003); 72, 042705 (2005)]. Agreement with those data is only marginal, being particularly poor at the overlap lower energies. Unlike Kimura et al. [J. Phys. B 37, 1461 (2004)], we find the low-energy dependence of the positron-benzene total cross sections to be qualitatively similar to those found in the electron channel [Gulley et al., J. Phys. B 31, 2735 (1998)]. We believe that the present positron-aniline total cross sections represent the first time such data have been measured. These cross sections are almost identical to those we found for benzene, suggesting that substitution of hydrogen by the amine group on the aromatic ring is largely irrelevant to the scattering process in the energy regimes considered.

  10. Positron impact excitations of hydrogen atom embedded in weakly coupled plasmas: Formation of Rydberg atoms

    SciTech Connect (OSTI)

    Rej, Pramit; Ghoshal, Arijit, E-mail: aghoshal@math.buruniv.ac.in [Department of Mathematics, Burdwan University, Golapbag, Burdwan 713 104, West Bengal (India)

    2014-09-15T23:59:59.000Z

    Formation of Rydberg atoms due to 1s?nlm excitations of hydrogen, for arbitrary n, l, m, by positron impact in weakly coupled plasma has been investigated using a distorted-wave theory in the momentum space. The interactions among the charged particles in the plasma have been represented by Debye-Huckel potentials. Making use of a simple variationally determined wave function for the hydrogen atom, it has been possible to obtain the distorted-wave scattering amplitude in a closed analytical form. A detailed study has been made on the effects of plasma screening on the differential and total cross sections in the energy range 20–300?eV of incident positron. For the unscreened case, our results agree nicely with some of the most accurate results available in the literature. To the best of our knowledge, such a study on the differential and total cross sections for 1s?nlm inelastic positron-hydrogen collisions for arbitrary n, l, m in weakly coupled plasmas is the first reported in the literature.

  11. Quench studies of ILC cavities

    SciTech Connect (OSTI)

    Eremeev, Grigory; Geng, Rongli; Palczewski, Ari; Dai, Jin

    2011-07-01T23:59:59.000Z

    Quench limits accelerating gradient in SRF cavities to a gradient lower than theoretically expected for superconducting niobium. Identification of the quenching site with thermometry and OST, optical inspection, and replica of the culprit is an ongoing effort at Jefferson Lab aimed at better understanding of this limiting phenomenon. In this contribution we present our finding with several SRF cavities that were limited by quench.

  12. Radiation source

    DOE Patents [OSTI]

    Thode, Lester E. (Los Alamos, NM)

    1981-01-01T23:59:59.000Z

    A device and method for relativistic electron beam heating of a high-density plasma in a small localized region. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises DT, DD, or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target gas is ionized prior to application of the relativistic electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region of the high-density plasma target.

  13. Multiplicity of Charged and Neutral Pions in Deep-Inelastic Scattering of 27.5 GeV Positrons on Hydrogen

    E-Print Network [OSTI]

    Airapetian, A; Amarian, M; Arrington, J; Aschenauer, E C; Avakian, H; Avakian, R; Avetisian, A; Avetissian, E; Bailey, P; Bains, B; Baumgarten, C; Beckmann, M; Belostotskii, S; Bernreuther, S; Bianchi, N; Böttcher, Helmut B; Borisov, A; Bouwhuis, M; Brack, J; Brauksiepe, S; Braun, B; Brückner, W; Brüll, A; Budz, P; Bulten, H J; Capitani, G P; Carter, P; Chumney, P; Cisbani, E; Court, G R; Dalpiaz, P F; De Leo, R; De Nardo, L; De Sanctis, E; De Schepper, D; Devitsin, E G; De Witt-Huberts, P K A; Di Nezza, P; Dzhordzhadze, V; Düren, M; Dvoredsky, A P; Elbakian, G M; Ely, J; Fantoni, A; Feshchenko, A; Ferro-Luzzi, M; Fiedler, K; Filippone, B W; Fischer, H; Fox, B; Franz, J; Frullani, S; Gärber, Y; Garibaldi, F; Garutti, E; Gavrilov, G E; Karibian, V; Golendukhin, A; Graw, G; Grebenyuk, O; Green, P W; Greeniaus, L G; Gute, A; Haeberli, W; Hartig, M; Hasch, D; Heesbeen, D; Heinsius, F H; Henoch, M; Hertenberger, R; Hesselink, W H A; Hoffmann-Rothe, P; Hofman, G J; Holler, Y; Holt, R J; Hommez, B; Hoprich, W; Iarygin, G; Ihssen, H; Iodice, M; Izotov, A A; Jackson, H E; Jgoun, A; Kaiser, R; Kanesaka, J; Kinney, E R; Kiselev, A; Kitching, P; Kobayashi, H; Koch, N; Königsmann, K C; Kolster, H; Korotkov, V A; Kotik, E; Kozlov, V; Krivokhizhin, V G; Kyle, G S; Lagamba, L; Laziev, A; Lenisa, P; Lindemann, T; Lorenzon, W; Makins, N C R; Martin, J W; Marukyan, H O; Masoli, F; McAndrew, M; McIlhany, K; McKeown, R D; Meissner, F; Menden, F; Metz, A; Meyners, N; Miklukho, O; Miller, C A; Milner, R; Muccifora, V; Mussa, R; Nagaitsev, A P; Nappi, E; Naryshkin, Yu; Nass, A; Nowak, Wolf-Dieter; O'Neill, T G; Openshaw, R; Ouyang, J; Owen, B R; Pate, S F; Potashov, S Yu; Potterveld, D H; Rakness, G; Redwine, R P; Reggiani, D; Reolon, A R; Ristinen, R; Rith, K; Robinson, D; Rostomyan, A; Ruh, M; Ryckbosch, D; Sakemi, Y; Sato, F; Savin, I A; Scarlett, C; Schäfer, A; Schill, C; Schmidt, F; Schmitt, M; Schnell, G; Schüler, K P; Schwind, A; Seibert, J; Shibata, T A; Shin, T; Shutov, V B; Simani, M C; Simon, A; Sinram, K; Steffens, E; Steijger, J J M; Stewart, J; Stösslein, U; Suetsugu, K; Sutter, M F; Tallini, H A; Taroian, S P; Terkulov, A R; Tessarin, S; Thomas, E; Tipton, B; Tytgat, M; Urciuoli, G M; Van den Brand, J F J; van der Steenhoven, G; Van de Vyver, R; Van Hunen, J J; Vetterli, Martin C; Vikhrov, V V; Vincter, M G; Visser, J; Volk, E; Weiskopf, C; Wendland, J; Wilbert, J; Wise, T; Woller, K; Yoneyama, S; Zohrabyan, H G

    2001-01-01T23:59:59.000Z

    Multiplicity of Charged and Neutral Pions in Deep-Inelastic Scattering of 27.5 GeV Positrons on Hydrogen

  14. MAGNETIC FIELD GENERATION AND PARTICLE ENERGIZATION AT RELATIVISTIC SHEAR BOUNDARIES IN COLLISIONLESS ELECTRON-POSITRON PLASMAS

    SciTech Connect (OSTI)

    Liang, Edison; Smith, Ian [Rice University, MS 108, 6100 Main Street, Houston, TX 77005 (United States); Boettcher, Markus, E-mail: liang@rice.edu, E-mail: iansmith@rice.edu, E-mail: boettchm@ohio.edu [Physics and Astronomy Department, Ohio University, Athens, OH 45701 (United States)

    2013-04-01T23:59:59.000Z

    Using particle-in-cell simulations, we study the kinetic physics of relativistic shear flow in collisionless electron-positron (e+e-) plasmas. We find efficient magnetic field generation and particle energization at the shear boundary, driven by streaming instabilities across the shear interface and sustained by the shear flow. Nonthermal, anisotropic high-energy particles are accelerated across field lines to produce a power-law tail turning over just below the shear Lorentz factor. These results have important implications for the dissipation and radiation of jets in blazars and gamma-ray bursts.

  15. Phase-mixing of electrostatic modes in a cold magnetized electron-positron plasma

    SciTech Connect (OSTI)

    Maity, Chandan; Chakrabarti, Nikhil [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)] [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Sengupta, Sudip [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)] [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)

    2013-08-15T23:59:59.000Z

    In a fluid description, we study space-time evolution of electrostatic oscillations in a cold magnetized electron-positron plasma. Nonlinear results up to third order, obtained by employing a simple perturbation technique, indicate phase-mixing and thus breaking of excited oscillations, and provide an expression for the phase-mixing time. It is shown that an increase in the strength of ambient magnetic field results in an increase in the phase-mixing time. The results of our investigation will be of relevance to astrophysical environments as well as laboratory experiments.

  16. Positron annihilation spectroscopy techniques applied to the study of an HPGe detector

    SciTech Connect (OSTI)

    Nascimento, E. do; Vanin, V. R.; Maidana, N. L.; Silva, T. F.; Rizzutto, M. A. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, SP (Brazil); Fernandez-Varea, J. M. [Facultat de Fisica (ECM), Universitat de Barcelona, Diagonal 645, E-08028 Barcelona (Spain)

    2013-05-06T23:59:59.000Z

    Doppler Broadening Spectroscopy of the large Ge crystal of an HPGe detector was performed using positrons from pair production of 6.13 MeV {gamma}-rays from the {sup 19}F(p,{alpha}{gamma}){sup 16}O reaction. Two HPGe detectors facing opposite sides of the Ge crystal acting as target provided both coincidence and singles spectra. Changes in the shape of the annihilation peak were observed when the high voltage applied to the target detector was switched on or off, amounting to somewhat less than 20% when the areas of equivalent energy intervals in the corresponding normalized spectra are compared.

  17. Photo-degradation of Lexan polycarbonate studied using positron lifetime spectroscopy

    SciTech Connect (OSTI)

    Hareesh, K.; Sanjeev, Ganesh [Microtron Centre, Department of Physics, Mangalore University, Mangalagangotri-574199 (India); Pandey, A. K. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India); Meghala, D.; Ranganathaiah, C. [Department of Studies in Physics, University of Mysore, Manasagangotri-570006 (India)

    2013-02-05T23:59:59.000Z

    The free volume properties of pristine and UV irradiated Lexan polycarbonate have been investigated using Positron Lifetime Spectroscopy (PLS). The decrease in o-Ps life time and free volume size of irradiated sample is attributed to free volume modification and formation of more stable free radicals. These free radicals are formed due to the breakage of C-O bonds in Lexan polycarbonate after irradiation. This is also supported by the decrease in the intensity of C-O bond after exposure to UV-radiation as studied from Fourier Transform Infrared (FTIR) spectroscopy and it also shows that benzene ring does not undergo any changes after irradiation.

  18. Spin polarized electron-positron pair production via elliptical polarized laser fields

    E-Print Network [OSTI]

    Wöllert, Anton; Keitel, Christoph H

    2015-01-01T23:59:59.000Z

    We study nonperturbative multiphoton electron-positron pair creation in ultra-strong electromagnetic fields formed by two counterpropagating pulses with elliptic polarization. Our numerical approach allows us to take into account the temporal as well as the spatial variation of the standing electromagnetic field. The spin and momentum resolved pair creation probabilities feature characteristic Rabi oscillations and resonance spectra. Therefore, each laser frequency features a specific momentum distribution of the created particles. We find that depending on the relative polarization of both pulses the created electrons may be spin polarized along the direction of field propagation.

  19. Spin polarized electron-positron pair production via elliptical polarized laser fields

    E-Print Network [OSTI]

    Anton Wöllert; Heiko Bauke; Christoph H. Keitel

    2015-02-23T23:59:59.000Z

    We study nonperturbative multiphoton electron-positron pair creation in ultra-strong electromagnetic fields formed by two counterpropagating pulses with elliptic polarization. Our numerical approach allows us to take into account the temporal as well as the spatial variation of the standing electromagnetic field. The spin and momentum resolved pair creation probabilities feature characteristic Rabi oscillations and resonance spectra. Therefore, each laser frequency features a specific momentum distribution of the created particles. We find that depending on the relative polarization of both pulses the created electrons may be spin polarized along the direction of field propagation.

  20. Towards a resolution of the proton form factor problem: new electron and positron scattering data

    E-Print Network [OSTI]

    D. Adikaram; D. Rimal; L. B. Weinstein; B. Raue; P. Khetarpal; R. P. Bennett; J. Arrington; W. K. Brooks; K. P. Adhikari; A. V. Afanasev; M. J. Amaryan; M. D. Anderson; J. Ball; M. Battaglieri; I. Bedlinskiy; A. S. Biselli; J. Bono; S. Boiarinov; W. J. Briscoe; V. D. Burkert; D. S. Carman; A. Celentano; S. Chandavar; G. Charles; L. Colaneri; P. L. Cole; M. Contalbrigo; A. D'Angelo; N. Dashyan; R. De Vita; E. De Sanctis; A. Deur; C. Djalali; G. E. Dodge; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; P. Eugenio; G. Fedotov; S. Fegan; A. Filippi; J. A. Fleming; A. Fradi; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; J. T. Goetz; W. Gohn; E. Golovatch; R. W. Gothe; K. A. Griffioen; M. Guidal; L. Guo; K. Hafidi; H. Hakobyan; N. Harrison; M. Hattawy; K. Hicks; M. Holtrop; S. M. Hughes; C. E. Hyde; Y. Ilieva; D. G. Ireland; B. S. Ishkhanov; D. Jenkins; H. Jiang; K. Joo; S. Joosten; M. Khandaker; W. Kim; A. Klein; F. J. Klein; S. Koirala; V. Kubarovsky; S. E. Kuhn; H. Y. Lu; I . J . D. MacGregor; N. Markov; M. Mayer; B. McKinnon; M. D. Mestayer; C. A. Meyer; M. Mirazita; V. Mokeev; R. A. Montgomery; C. I. Moody; H. Moutarde; A Movsisyan; C. Munoz Camacho; P. Nadel-Turonski; S. Niccolai; G. Niculescu; M. Osipenko; A. I. Ostrovidov; K. Park; E. Pasyuk; S. Pisano; O. Pogorelko; S. Procureur; Y. Prok; D. Protopopescu; A. J. R. Puckett; M. Ripani; A. Rizzo; G. Rosner; P. Rossi; F. Sabatié; D. Schott; R. A. Schumacher; Y. G. Sharabian; A. Simonyan; I. Skorodumina; E. S. Smith; G. D. Smith; D. I. Sober; N. Sparveris; S. Stepanyan; S. Strauch; V. Sytnik; M. Taiuti; Ye Tian; A. Trivedi; M. Ungaro; H. Voskanyan; E. Voutier; N. K. Walford; D. P. Watts; X. Wei; M. H. Wood; N. Zachariou; L. Zana; J. Zhang; Z. W. Zhao; I. Zonta; The CLAS Collaboration

    2014-11-25T23:59:59.000Z

    There is a significant discrepancy between the values of the proton electric form factor, $G_E^p$, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of $G_E^p$ from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization ($\\varepsilon$) and momentum transfer ($Q^2$) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing $\\varepsilon$ at $Q^2 = 1.45 \\text{ GeV}^2$. This measurement is consistent with the size of the form factor discrepancy at $Q^2\\approx 1.75$ GeV$^2$ and with hadronic calculations including nucleon and $\\Delta$ intermediate states, which have been shown to resolve the discrepancy up to $2-3$ GeV$^2$.

  1. Electron-positron pair oscillation in spatially inhomogeneous electric fields and radiation

    E-Print Network [OSTI]

    Wen-Biao Han; Remo Ruffini; She-Sheng Xue

    2010-06-11T23:59:59.000Z

    It is known that strong electric fields produce electron and positron pairs from the vacuum, and due to the back-reaction these pairs oscillate back and forth coherently with the alternating electric fields in time. We study this phenomenon in spatially inhomogeneous and bound electric fields by integrating the equations of energymomentum and particle-number conservations and Maxwell equations. The space and time evolutions of the pair-induced electric field, electric charge- and currentdensities are calculated. The results show that non-vanishing electric charge-density and the propagation of pair-induced electric fields, differently from the case of homogeneous and unbound electric fields. The space and time variations of pair-induced electric charges and currents emit an electromagnetic radiation. We obtain the narrow spectrum and intensity of this radiation, whose peak {\\omega}peak locates in the region around 4 KeV for electric field strength \\sim Ec. We discuss their relevances to both the laboratory experiments for electron and positron pair-productions and the astrophysical observations of compact stars with an electromagnetic structure.

  2. Towards a Resolution of the Proton Form Factor Problem: New Electron and Positron Scattering Data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Adikaram, D; Rimal, D; Weinstein, L B.; Raue, B; Khetarpal, P; Bennett, R; Arrington, J; Brooks, W; Adhikari, K; Afanasev, A; et al

    2015-02-01T23:59:59.000Z

    There is a significant discrepancy between the values of the proton electric form factor, GpE, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GpE from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (epsilon) and momentummore »transfer (Q2) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ? at Q2=1.45 GeV2. This measurement is consistent with the size of the form factor discrepancy at Q2?1.75 GeV2 and with hadronic calculations including nucleon and Delta intermediate states, which have been shown to resolve the discrepancy up to 2-3 GeV2.« less

  3. Towards a Resolution of the Proton Form Factor Problem: New Electron and Positron Scattering Data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Adikaram, D.; Rimal, D.; Weinstein, L B.; Raue, B.; Khetarpal, P.; Bennett, R; Arrington, J.; Brooks, W; Adhikari, K; Afanasev, A; Amaryan, M; Anderson, M; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A; Bono, J.; Boiarinov, S.; Briscoe, W; Burkert, V; Carman, D; Careccia, S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P; Contalbrigo, M.; Crede, V.; D'Angelo, A; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J; Fradi, A.; Garillon, B.; Gilfoyle, G; Giovanetti, K; Girod, F; Goetz, J; Gohn, W.; Golovatch, E.; Gothe, R; Griffioen, K; Guegan, B.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S; Hyde, C E; Ilieva, Y.; Ireland, D; Ishkhanov, B; Jenkins, D.; Jiang, H.; Jo, H; Joo, K.; Joosten, S.; Kalantarians, N.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F; Koirala, S.; Kubarovsky, V.; Kuhn, S; Livingston, K.; Lu, H; MacGregor, I; Markov, N.; Mattione, P.; Mayer, M.; McKinnon, B.; Mestayer, M; Meyer, C; Mirazita, M.; Mokeev, V.; Montgomery, R; Moody, C; Moutarde, H.; Movsisyan, A.; Camacho, C. Munoz; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Osipenko, M.; Ostrovidov, A; Park, K.; Pasyuk, E.; Pisano, S.; Pogorelko, O.; Price, J; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabati, F; Salgado, C.; Schott, D.; Schumacher, R; Seder, E.; Sharabian, Y; Simonyan, A.; Skorodumina, I.; Smith, E; Smith, G; Sober, D; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tian, Ye; Trivedi, A.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N; Watts, D; Wei, X.; Wood, M; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z; Zonta, I.

    2015-02-10T23:59:59.000Z

    There is a significant discrepancy between the values of the proton electric form factor, GpE, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GpE from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (epsilon) and momentum transfer (Q2) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ? at Q2=1.45 GeV2. This measurement is consistent with the size of the form factor discrepancy at Q2?1.75 GeV2 and with hadronic calculations including nucleon and Delta intermediate states, which have been shown to resolve the discrepancy up to 2-3 GeV2.

  4. Electroweak Measurements in Electron-Positron Collisions at W-Boson-Pair Energies at LEP

    E-Print Network [OSTI]

    Schael, S; Bruneliere, R; Buskulic, D; De Bonis, I; Decamp, D; Ghez, P; Goy, C; Jezequel, S; Lees, J P; Lucotte, A; Martin, F; Merle, E; Minard, M N; Nief, J Y; Odier, P; Pietrzyk, B; Trocme, B; Bravo, S; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Fernandez, E; Fernandez-Bosman, M; Garrido, Ll; Grauges, E; Juste, A; Martinez, M; Merino, G; Miquel, R; Mir, Ll. M; Orteu, S; Pacheco, A; Park, I C; Perlas, J; Riu, I; Ruiz, H; Sanchez, F; Colaleo, A; Creanza, D; De Filippis, N; De Palma, M; Iaselli, G; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Bazarko, A; Becker, U; Boix, G; Bird, F; Blucher, E; Bonvicini, B; Bright-Thomas, P; Barklow, T; Buchmuller, O; Cattaneo, M; Cerutti, F; Ciulli, V; Clerbaux, B; Drevermann, H; Forty, R W; Frank, M; Greening, T C; Hagelberg, R; Halley, A W; Gianotti, F; Girone, M; Hansen, J B; Harvey, J; Jacobsen, R; Hutchcroft, D E; Janot, P; Jost, B; Knobloch, J; Kado, M; Lehraus, I; Lazeyras, P; Maley, P; Mato, P; May, J; Moutoussi, A; Pepe-Altarelli, M; Ranjard, F; Rolandi, L; Schlatter, D; Schmitt, B; Schneider, O; Tejessy, W; Teubert, F; Tomalin, I R; Tournefier, E; Veenhof, R; Valassi, A; Wiedenmann, W; Wright, A E; Ajaltouni, Z; Badaud, F; Chazelle, G; Deschamps, O; Dessagne, S; Falvard, A; Ferdi, C; Fayolle, D; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Pascolo, J M; Perret, P; Podlyski, F; Bertelsen, H; Fernley, T; Hansen, J D; Hansen, J R; Hansen, P H; Kraan, A C; Lindahl, A; Mollerud, R; Nilsson, B S; Rensch, B; Waananen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, E; Siotis, I; Vayaki, A; Zachariadou, K; Blondel, A; Bonneaud, G; Brient, J C; Machefert, F; Rouge, A; Rumpf, M; Swynghedauw, M; Tanaka, R; Verderi, M; Videau, H; Ciulli, V; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C; Antonelli, A; Antonelli, M; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Cerutti, F; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, G P; Passalacqua, L; Picchi, P; Colrain, P; Have, I. ten; Hughes, I S; Kennedy, J; Knowles, I G; Lynch, J G; Morton, W T; Negus, P; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Thompson, A S; Turnbull, R M; Wasserbaech, S; Buchmuller, O; Cavanaugh, R; Dhamotharan, S; Geweniger, C; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Stenzel, H; Tittel, K; Werner, W; Wunsch, M; Beuselinck, R; Binnie, D M; Cameron, W; Davies, G; Dornan, P J; Goodsir, S; Marinelli, N; Martin, E B; Nash, J; Nowell, J; Rutherford, S A; Sedgbeer, J K; Thompson, J C; White, R; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bouhova-Thacker, E; Bowdery, C K; Buck, P G; Clarke, D P; Ellis, G; Finch, A J; Foster, F; Hughes, G; Jones, R.W L; Keemer, N R; Pearson, M R; Robertson, N A; Sloan, T; Smizanska, M; Snow, S W; Williams, M I; van der Aa, O; Delaere, C; Leibenguth, G; Lemaitre, V; Bauerdick, L.A T; Blumenschein, U; van Gemmeren, P; Giehl, I; Holldorfer, F; Jakobs, K; Kasemann, M; Kayser, F; Kleinknecht, K; Muller, A S; Quast, G; Renk, B; Rohne, E; Sander, H G; Schmeling, S; Wachsmuth, H; Wanke, R; Zeitnitz, C; Ziegler, T; Aubert, J J; Benchouk, C; Bonissent, A; Carr, J; Coyle, P; Curtil, C; Ealet, A; Etienne, F; Fouchez, D; Motsch, F; Payre, P; Rousseau, D; Tilquin, A; Talby, M; Thulasidas, M; Aleppo, M; Antonelli, M; Ragusa, F; Buscher, V; David, A; Dietl, H; Ganis, G; Huttmann, K; Lutjens, G; Mannert, C; Manner, W; Moser, H G; Settles, R; Seywerd, H; Stenzel, H; Villegas, M; Wiedenmann, W; Wolf, G; Azzurri, P; Boucrot, J; Callot, O; Chen, S; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, Ph; Jacholkowska, A; Le Diberder, F; Lefrancois, J; Mutz, A M; Schune, M H; Serin, L; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Bettarini, S; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Fantechi, R; Ferrante, I; Fidecaro, F; Foa, L; Giammanco, A; Giassi, A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, F; Rizzo, G; Sanguinetti, G; Sciaba, A; Sguazzoni, G; Spagnolo, P; Steinberger, J; Tenchini, R; Vannini, C; Venturi, A; Verdini, P G; Awunor, O; Blair, G A; Cowan, G; Garcia-Bellido, A; Green, M G; Medcalf, T; Misiejuk, A; Strong, J A; Teixeira-Dias, P; Botterill, D R; Clifft, R W; Edgecock, T R; Edwards, M; Haywood, S J; Norton, P R; Tomalin, I R; Ward, J J; Bloch-Devaux, B; Boumediene, D; Colas, P; Emery, S; Fabbro, B; Kozanecki, W; Lancon, E; Lemaire, M C; Locci, E; Perez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Tuchming, B; Vallage, B; Black, S N; Dann, J H; Kim, H Y; Konstantinidis, N; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S

    2013-01-01T23:59:59.000Z

    Electroweak measurements performed with data taken at the electron-positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3~fb$^{-1}$ collected by the four LEP experiments ALEPH, DELPHI, L3 and OPAL, at centre-of-mass energies ranging from $130~GeV$ to $209~GeV$. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron-positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose-Einstein correlations between the two W decay systems arising ...

  5. The Linac Injector For The ANL 7 Ge V Advanced Photon Source

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    quadrupole triplets are adequate to provide focusing and transport properties. Positron Production Following the DESY design, the positrons are produced in a water-cooled,...

  6. Electron and Positron Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

    E-Print Network [OSTI]

    Becker, Ulrich J.

    Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. ...

  7. Electrolytes for power sources

    DOE Patents [OSTI]

    Doddapaneni, N.; Ingersoll, D.

    1995-01-03T23:59:59.000Z

    Electrolytes are disclosed for power sources, particularly alkaline and acidic power sources, comprising benzene polysulfonic acids and benzene polyphosphonic acids or salts of such acids. 7 figures.

  8. Electrolytes for power sources

    DOE Patents [OSTI]

    Doddapaneni, Narayan (Albuquerque, NM); Ingersoll, David (Albuquerque, NM)

    1995-01-01T23:59:59.000Z

    Electrolytes for power sources, particularly alkaline and acidic power sources, comprising benzene polysulfonic acids and benzene polyphosphonic acids or salts of such acids.

  9. Cascade phonon-assisted trapping of positrons by divacancies in n-FZ-Si(P) single crystals irradiated with 15 MeV protons

    SciTech Connect (OSTI)

    Arutyunov, N. Yu., E-mail: n-arutyunov@yahoo.com [Martin Luther University Halle, Department of Physics, 06120 Halle, Germany and Inst. of Ion-Plasma and Laser Technologies (Inst. of Electronics), 700187 Tashkent (Uzbekistan); Emtsev, V. V.; Oganesyan, G. A. [Ioffe Physico-Technical Institute, 194021 St. Petersburg (Russian Federation); Krause-Rehberg, R.; Kessler, C. [Martin Luther University Halle, Department of Physics, 06120 Halle (Germany); Elsayed, M. [Martin Luther University Halle, Department of Physics, 06120 Halle, Germany and Minia university, Faculty of Science, Physics Department, P.O. box 61519 Minia (Egypt); Kozlovski, V. V. [St. Petersburg State Polytechnic University, 195251 St. Petersburg (Russian Federation)

    2014-02-21T23:59:59.000Z

    The trapping of positrons by the radiation defects in moderately doped oxygen-lean n-FZ-Si(P) single crystal irradiated with 15 MeV protons has been investigated in a comparative way using the positron lifetime spectroscopy and Hall effect measurements. The experiments were carried out within a wide temperature interval ranging from 25 K – 29 K to 300 K. The positron trapping rate for divacancies was reconstructed in the course of many-stage isochronal annealing. The concentration and the charged states of divacancies (V{sub 2}{sup ?} and V{sub 2}{sup ??}) were estimated. The temperature dependency of the trapping cross section of positrons by the negatively charged divacancies is in a good agreement with the data of calculations based on the assumptions of the cascade phonon-assisted mechanism of exchange of the energy between the positron and acoustic long-wave phonons. Obeying ? T{sup ?3} law, the cross-section of the trapping of positrons by divacancies changes considerably ranging from ?1.7×10{sup ?12} cm{sup 2} (66 – 100 K) to ?2×10{sup ?14} cm{sup 2} (? 250 K). The characteristic length of trapping of the positron by V{sub 2}{sup ??} divacancy was estimated to be l{sub 0}(V{sub 2}{sup ??})?(3.4±0.2)×10{sup ?8} cm.

  10. A new mode and its interaction through ponderomotive force in electron-positron-ion plasmas

    SciTech Connect (OSTI)

    Haque, Q.; Masood, W. [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); National Centre for Physics, Islamabad (Pakistan); Tsintsadze, N. L. [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); Department of Plasma Physics, E. Andronikashvili Institute of Physics, Tbilisi (Georgia)

    2011-12-15T23:59:59.000Z

    A new mode is found in e-p-i plasma in the presence of density and temperature difference of lighter particles. The electron beam induced Cherenkov instability condition for the excitation of positron sound wave is obtained for the system under consideration. Zakharov's equation with sign modification due to negative Ponderomotive pressure is obtained. Nonlinear Schroedinger wave equation for the envelope type solitary waves is derived. Both stationary and nonstationary solutions are found and the subsonic and supersonic limits are also discussed. In the stationary case, rarefactive type solitary solution is obtained, whereas the nonstationary case yields the ion acoustic shock like structure solution which is very interesting. The importance of the study with relevance to both laboratory and astrophysical plasmas is pointed out.

  11. Planar and cylindrical magnetosonic solitary and shock waves in dissipative, hot electron-positron-ion plasma

    SciTech Connect (OSTI)

    Jehan, Nusrat [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Pakistan Atomic Energy Commission, P. O. Box 1114, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Salahuddin, M. [Pakistan Atomic Energy Commission, P. O. Box 1114, Islamabad 44000 (Pakistan)

    2011-05-15T23:59:59.000Z

    Planar and cylindrical magnetosonic solitary and shock structures are studied in a hot and dissipative plasma consisting of electrons, positrons, and ions. By employing the reductive perturbative method, a modified Korteweg-de Vries Burgers (mKdVB) equation is derived in the limit of low frequency and long wavelength by taking into account viscous dissipation of the three species. The effects of variation of various plasma parameters on the profiles of planar and cylindrical solitary and shock structures are discussed. In the limit, when certain terms of the mKdVB equation are small enough to be treated as perturbation, analytical solutions are obtained and compared with the corresponding numerical ones.

  12. Annealing properties of open volumes in strained SiN films studied by monoenergetic positron beams

    SciTech Connect (OSTI)

    Uedono, A.; Ito, K.; Narumi, T.; Sometani, M.; Yamabe, K.; Miyagawa, Y.; Murata, T.; Honda, K.; Hattori, N.; Matsuura, M.; Asai, K.; Ohdaira, T.; Suzuki, R. [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Process Technology Development Division, Renesas Technology Corp., 4-1 Mizuhara, Itami, Hyogo 664-0005 (Japan); National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2007-09-15T23:59:59.000Z

    The effect of annealing on open volumes in strained SiN films deposited on Si by plasma enhanced chemical vapor deposition was studied using monoenergetic positron beams. For compressive SiN, the stress was reduced by postdeposition annealing; this effect was attributed to the relaxation of matrix structures accompanied by an expansion of small open spaces intrinsically existing in the matrix and the introduction of large open volumes. For tensile SiN, although annealing tends to decrease the concentration of large open volumes, the size of the small open spaces and the film stress were almost constant up to 1000 deg. C annealing. This was attributed to the network structure related to the open spaces remaining stable even at 1000 deg. C annealing, and this mainly determines the stress in the tensile film.

  13. Semiclassical description of nonlinear electron-positron photoproduction in strong laser fields

    E-Print Network [OSTI]

    Sebastian Meuren; Christoph H. Keitel; Antonino Di Piazza

    2015-03-11T23:59:59.000Z

    The nonlinear Breit-Wheeler process is studied in the presence of strong and short laser pulses. We show that for a relativistically intense plane-wave laser field many aspects of the momentum distribution for the produced electron-positron pair like its extend, region of highest probability and carrier-envelope phase effects can be explained from the classical evolution of the created particles in the background field. To this end we verify that the local constant-crossed field approximation is also appropriate for the calculation of the spectrum if applied on the probability-amplitude level. To compare the exact expressions with the semiclassical approach, we introduce a very fast numerical scheme, which makes it feasible to completely resolve the interference structure of the spectrum over the available multidimensional phase space.

  14. Semiclassical description of nonlinear electron-positron photoproduction in strong laser fields

    E-Print Network [OSTI]

    Meuren, Sebastian; Di Piazza, Antonino

    2015-01-01T23:59:59.000Z

    The nonlinear Breit-Wheeler process is studied in the presence of strong and short laser pulses. We show that for a relativistically intense plane-wave laser field many aspects of the momentum distribution for the produced electron-positron pair like its extend, region of highest probability and carrier-envelope phase effects can be explained from the classical evolution of the created particles in the background field. To this end we verify that the local constant-crossed field approximation is also appropriate for the calculation of the spectrum if applied on the probability-amplitude level. To compare the exact expressions with the semiclassical approach, we introduce a very fast numerical scheme, which makes it feasible to completely resolve the interference structure of the spectrum over the available multidimensional phase space.

  15. Phase-mixing of Langmuir oscillations in cold electron-positron-ion plasmas

    SciTech Connect (OSTI)

    Maity, Chandan [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)

    2014-07-15T23:59:59.000Z

    Space-time evolution of Langmuir oscillations in a cold homogeneous electron-positron-ion plasma has been analyzed by employing a straightforward perturbation expansion method, showing phase-mixing and, thus, wave-breaking of excited oscillations at arbitrary amplitudes. Within an assumption of infinitely massive ions, an approximate phase-mixing time is found to scale as ?{sub pe}t{sub mix}?[(6/?{sup 2})((2??){sup 5/2}/(1??))]{sup 1/3}, where “?” and “?” (= n{sub 0i}/n{sub 0e}) are the amplitude of perturbation and the ratio of equilibrium ion density to equilibrium electron density, respectively, and ?{sub pe}??(4?n{sub 0e}e{sup 2}/m) is the electron plasma frequency. The results presented on phase-mixing of Langmuir modes in multispecies plasmas are expected to be relevant to laboratory and astrophysical environments.

  16. Photoluminescence and positron annihilation spectroscopy investigation of (Ge, Er) codoped Si oxides deposited by magnetron sputtering

    SciTech Connect (OSTI)

    Heng, C. L.; Chelomentsev, E.; Peng, Z. L.; Mascher, P. [Department of Engineering Physics and Centre for Emerging Device Technologies, McMaster University, Hamilton, Ontario L8S 4K1 (Canada); Simpson, P. J. [Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada)

    2009-01-01T23:59:59.000Z

    We have investigated the nature of violet-blue emission from (Ge, Er) codoped Si oxides (Ge+Er+SiO{sub 2}) using photoluminescence (PL) and positron annihilation spectroscopy (PAS) measurements. The PL spectra and PAS analysis for a control Ge-doped SiO{sub 2} (Ge+SiO{sub 2}) indicate that Ge-associated neutral oxygen vacancies (Ge-NOV) are likely responsible for the major emission in the violet-blue band. For Ge+Er+SiO{sub 2}, both Ge-NOV and GeO color centers are believed to be responsible for the emission band. The addition of Er has a significant influence on the emission, which is discussed in terms of Er-concentration-related structural change in the Ge+Er+SiO{sub 2}.

  17. Investigation into electron cloud effects in the International Linear Collider positron damping ring

    SciTech Connect (OSTI)

    Crittenden, J.A.; Conway, J.; Dugan, G.F.; Palmer, M.A.; Rubin, D.L.; Shanks, J.; Sonnad, K.G.; Boon, L.; Harkay, K.; Ishibashi, T.; Furman, M.A.; Guiducci, S.; Pivi, M.T.F.; Wang, L.; Crittenden, J.A.; Conway, J.; Dugan, G.F.; Palmer, M.A.; Rubin, D.L.; Shanks, J.; Sonnad, K.G.; Boon, L.; Harkay, K.; Ishibashi, T.; Furman, M.A.; Guiducci, S.; Pivi, M.T.F.; Wang, L.

    2014-02-28T23:59:59.000Z

    We report modeling results for electron cloud buildup and instability in the International Linear Collider positron damping ring. Updated optics, wiggler magnets, and vacuum chamber designs have recently been developed for the 5 GeV, 3.2-km racetrack layout. An analysis of the synchrotron radiation profile around the ring has been performed, including the effects of diffuse and specular photon scattering on the interior surfaces of the vacuum chamber. The results provide input to the cloud buildup simulations for the various magnetic field regions of the ring. The modeled cloud densities thus obtained are used in the instability threshold calculations. We conclude that the mitigation techniques employed in this model will suffice to allow operation of the damping ring at the design operational specifications

  18. Three-dimensional nonlinear Schroedinger equation in electron-positron-ion magnetoplasmas

    SciTech Connect (OSTI)

    Sabry, R. [Department of Physics, College of Science and Humanitarian Studies, Alkharj University, Alkharj 11942 (Saudi Arabia); Department of Physics, Theoretical Physics Group, Faculty of Science, Mansoura University, Damietta-Branch, New Damietta, 34517 Damietta (Egypt); Moslem, W. M. [Department of Physics, Faculty of Science, Port Said University, Port Said (Egypt); El-Shamy, E. F. [Department of Physics, Theoretical Physics Group, Faculty of Science, Mansoura University, Damietta-Branch, New Damietta, 34517 Damietta (Egypt); Shukla, P. K. [RUB International Chair, Faculty of Physics and Astronomy, International Centre for Advanced Studies in Physical Sciences, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

    2011-03-15T23:59:59.000Z

    Three-dimensional ion-acoustic envelope soliton excitations in electron-positron-ion magnetoplasmas are interpreted. This is accomplished through the derivation of three-dimensional nonlinear Schroedinger equation, where the nonlinearity is balancing with the dispersive terms. The latter contains both an external magnetic field besides the usual plasma parameter effects. Based on the balance between the nonlinearity and the dispersion terms, the regions for possible envelope solitons are investigated indicating that new regimes for modulational instability of envelope ion-acoustic waves could be obtained, which cannot exist in the unmagnetized case. This will allow us to establish additional new regimes, different from the usual unmagnetized plasma, for envelope ion-acoustic waves to propagate in multicomponent plasma that may be observed in space or astrophysics.

  19. Electron and Positron Capture Rates on $\\bf{^{55}}$Co in Stellar Matter

    E-Print Network [OSTI]

    Jameel-Un Nabi; Muneeb-Ur Rahman; Muhammad Sajjad

    2014-08-15T23:59:59.000Z

    Cobalt-55 is not only present in abundance in presupernova phase but is also advocated to play a decisive role in the core collapse of massive stars. The spectroscopy of electron capture and emitted neutrinos yields useful information on the physical conditions and stellar core composition. B(GT) values to low-lying states are calculated microscopically using the pn-QRPA theory. Our rates are enhanced compared to the shell model rates. The enhancement is attributed partly to the liberty of selecting a huge model space, allowing consideration of many more parent excited states in our rate calculation. Unlike previous calculations, the so-called Brink's hypothesis is not assumed leading to a more realistic estimate of the rates. The electron and positron capture rates are calculated over a wide temperature and density grid.

  20. Causal approach for the electron-positron scattering in Generalized Quantum Electrodynamics

    E-Print Network [OSTI]

    R. Bufalo; B. M. Pimentel; D. E. Soto

    2014-10-14T23:59:59.000Z

    In this paper we study the generalized electrodynamics contribution for the electron-positron scattering process, $e^{-}e^{+}\\rightarrow e^{-}e^{+}$, the Bhabha scattering. Within the framework of the standard model, for energies larger when compared to the electron mass, we calculate the cross section expression for the scattering process. This quantity is usually calculated in the framework of the Maxwell electrodynamics and, by phenomenological reasons, corrected by a cut-off parameter. On the other hand, by considering the generalized electrodynamics instead of Maxwell's, we can show that the effects played by the Podolsky mass is actually a natural cut-off parameter for this scattering process. Furthermore, by means of experimental data of Bhabha scattering we will estimate its lower bound value. Nevertheless, in order to have a mathematically well defined description of our study we shall present our discussion in the framework of the Epstein-Glaser causal theory.

  1. Evaluating the purity of a {sup 57}Co flood source by PET

    SciTech Connect (OSTI)

    DiFilippo, Frank P., E-mail: difilif@ccf.org [Department of Nuclear Medicine, Cleveland Clinic, Cleveland, Ohio 44195 (United States)

    2014-11-01T23:59:59.000Z

    Purpose: Flood sources of {sup 57}Co are commonly used for quality control of gamma cameras. Flood uniformity may be affected by the contaminants {sup 56}Co and {sup 58}Co, which emit higher energy photons. Although vendors specify a maximum combined {sup 56}Co and {sup 58}Co activity, a convenient test for flood source purity that is feasible in a clinical environment would be desirable. Methods: Both {sup 56}Co and {sup 58}Co emit positrons with branching 19.6% and 14.9%, respectively. As is known from {sup 90}Y imaging, a positron emission tomography (PET) scanner is capable of quantitatively imaging very weak positron emission in a high single-photon background. To evaluate this approach, two {sup 57}Co flood sources were scanned with a clinical PET/CT multiple times over a period of months. The {sup 56}Co and {sup 58}Co activity was clearly visible in the reconstructed PET images. Total impurity activity was quantified from the PET images after background subtraction of prompt gamma coincidences. Results: Time-of-flight PET reconstruction was highly beneficial for accurate image quantification. Repeated measurements of the positron-emitting impurities showed excellent agreement with an exponential decay model. For both flood sources studied, the fit parameters indicated a zero intercept and a decay half-life consistent with a mixture of {sup 56}Co and {sup 58}Co. The total impurity activity at the reference date was estimated to be 0.06% and 0.07% for the two sources, which was consistent with the vendor’s specification of <0.12%. Conclusions: The robustness of the repeated measurements and a thorough analysis of the detector corrections and physics suggest that the accuracy is acceptable and that the technique is feasible. Further work is needed to validate the accuracy of this technique with a calibrated high resolution gamma spectrometer as a gold standard, which was not available for this study, and for other PET detector models.

  2. BROOKHAVEN NATIONAL Sealed Source

    E-Print Network [OSTI]

    Homes, Christopher C.

    BROOKHAVEN NATIONAL LABORATORY Sealed Source Contamination Incident October 13, 2011 #12;2 Cesium (Cs-137) Source Failure On September 28th @ ~1600 contamination event discovered · Two Radiological Contamination was from a Cs-137 (265 micro-curie) "sealed source" used to test area radiation monitors. · Source

  3. The interaction of two nonplanar solitary waves in electron-positron-ion plasmas: An application in active galactic nuclei

    SciTech Connect (OSTI)

    EL-Labany, S. K.; Khedr, D. M. [Department of Physics, Faculty of Science, Damietta University, Damietta El-Gedida 34517 (Egypt); El-Shamy, E. F. [Department of Physics, Faculty of Science, Damietta University, Damietta El-Gedida 34517 (Egypt); Department of Physics, College of Science, King Khalid University, P.O. 9004, Abha (Saudi Arabia); Sabry, R. [Department of Physics, Faculty of Science, Damietta University, Damietta El-Gedida 34517 (Egypt); Department of Physics, College of Science and Humanitarian Studies, Salman bin Abdulaziz University, Alkharj (Saudi Arabia)

    2013-01-15T23:59:59.000Z

    In the present research paper, the effect of bounded nonplanar (cylindrical and spherical) geometry on the interaction between two nonplanar electrostatic solitary waves (NESWs) in electron-positron-ion plasmas has been studied. The extended Poincare-Lighthill-Kuo method is used to obtain nonplanar phase shifts after the interaction of the two NESWs. This study is a first attempt to investigate nonplanar phase shifts and trajectories for NESWs in a two-fluid plasma (a pair-plasma) consisting of electrons and positrons, as well as immobile background positive ions in nonplanar geometry. The change of phase shifts and trajectories for NESWs due to the effect of cylindrical geometry, spherical geometry, the physical processes (either isothermal or adiabatic), and the positions of two NESWs are discussed. The present investigation may be beneficial to understand the interaction between two NESWs that may occur in active galactic nuclei.

  4. Dense electron-positron plasmas and bursts of gamma-rays from laser-generated quantum electrodynamic plasmas

    SciTech Connect (OSTI)

    Ridgers, C. P.; Bell, A. R. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom)] [Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom); Brady, C. S.; Bennett, K.; Arber, T. D. [Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry, CV4 7AL (United Kingdom)] [Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry, CV4 7AL (United Kingdom); Duclous, R. [Commissariat à l'Energie Atomique, DAM DIF, F-91297 Arpajon (France)] [Commissariat à l'Energie Atomique, DAM DIF, F-91297 Arpajon (France); Kirk, J. G. [Max-Planck-Institut für Kernphysik, Postfach 10 39 80, 69029 Heidelberg (Germany)] [Max-Planck-Institut für Kernphysik, Postfach 10 39 80, 69029 Heidelberg (Germany)

    2013-05-15T23:59:59.000Z

    In simulations of a 12.5 PW laser (focussed intensity I=4×10{sup 23}Wcm{sup ?2}) striking a solid aluminum target, 10% of the laser energy is converted to gamma-rays. A dense electron-positron plasma is generated with a maximum density of 10{sup 26}m{sup ?3}, seven orders of magnitude denser than pure e{sup ?} e{sup +} plasmas generated with 1PW lasers. When the laser power is increased to 320 PW (I=10{sup 25}Wcm{sup ?2}), 40% of the laser energy is converted to gamma-ray photons and 10% to electron-positron pairs. In both cases, there is strong feedback between the QED emission processes and the plasma physics, the defining feature of the new “QED-plasma” regime reached in these interactions.

  5. High-speed digitization readout of silicon photomultipliers for time of flight positron emission tomography

    SciTech Connect (OSTI)

    Ronzhin, A.; Los, S.; Martens, M.; Ramberg, E.; /Fermilab; Kim, H.; Chen, C.; Kao, C.; /Chicago U.; Niessen, K.; /SUNY, Buffalo; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez; Mazzillo, M.; Carbone, B.; /SGS Thomson, Catania

    2011-02-01T23:59:59.000Z

    We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's. The readout of these devices used the commercial high speed digitizer DRS4. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module. The field of positron-emission-tomography (PET) has been rapidly developing. But there are significant limitations in how well current PET scanners can reconstruct images, related to how fast data can be acquired, how much volume they can image, and the spatial and temporal resolution of the generated photons. Typical modern scanners now include multiple rings of detectors, which can image a large volume of the patient. In this type of scanner, one can treat each ring as a separate detector and require coincidences only within the ring, or treat the entire region viewed by the scanner as a single 3 dimensional volume. This 3d technique has significantly better sensitivity since more photon pair trajectories are accepted. However, the scattering of photons within the volume of the patient, and the effect of random coincidences limits the technique. The advent of sub-nanosecond timing resolution detectors means that there is potentially much better rejection of scattered photon events and random coincidence events in the 3D technique. In addition, if the timing is good enough, then the origin of photons pairs can be determined better, resulting in improved spatial resolution - so called 'Time-of-Flight' PET, or TOF-PET. Currently a lot of activity has occurred in applications of SiPMs for TOF-PET. This is due to the devices very good time resolution, low profile, lack of high voltage needed, and their non-sensitivity to magnetic fields. While investigations into this technique have begun elsewhere, we feel that the extensive SiPM characterization and data acquisition expertise of Fermilab, and the historical in-depth research of PET imaging at University of Chicago will combine to make significant strides in this field. We also benefit by a working relationship with the SiPM producer STMicroelectronics (STM).

  6. Improvement of the technique of identification of electrons and positrons with use of electromagnetic calorimeter of the CLAS detector

    SciTech Connect (OSTI)

    Gevorgyan, N. E.; Dashyan, N. B.; Paremuzyan, R. G.; Stepanyan, S. G.

    2010-01-01T23:59:59.000Z

    We study the dependence of the sensitivity of response of the electromagnetic calorimeter of CLAS plant on the momenta of electrons and positrons. We made calculation of this dependence and elaborated a method for its employment in identification of e- and e+. We have shown that the new method of selection of e- and e+ improves the quality of identification by about 10%. We used the experimental data obtained with the plant CLAS of linear accelerator at Jefferson laboratory (USA).

  7. Low background high efficiency radiocesium detection system based on positron emission tomography technology

    SciTech Connect (OSTI)

    Yamamoto, Seiichi; Ogata, Yoshimune [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673 (Japan)] [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673 (Japan)

    2013-09-15T23:59:59.000Z

    After the 2011 nuclear power plant accident at Fukushima, radiocesium contamination in food became a serious concern in Japan. However, low background and high efficiency radiocesium detectors are expensive and huge, including semiconductor germanium detectors. To solve this problem, we developed a radiocesium detector by employing positron emission tomography (PET) technology. Because {sup 134}Cs emits two gamma photons (795 and 605 keV) within 5 ps, they can selectively be measured with coincidence. Such major environmental gamma photons as {sup 40}K (1.46 MeV) are single photon emitters and a coincidence measurement reduces the detection limit of radiocesium detectors. We arranged eight sets of Bi{sub 4}Ge{sub 3}O{sub 12} (BGO) scintillation detectors in double rings (four for each ring) and measured the coincidence between these detectors using PET data acquisition system. A 50 × 50 × 30 mm BGO was optically coupled to a 2 in. square photomultiplier tube (PMT). By measuring the coincidence, we eliminated most single gamma photons from the energy distribution and only detected those from {sup 134}Cs at an average efficiency of 12%. The minimum detectable concentration of the system for the 100 s acquisition time is less than half of the food monitor requirements in Japan (25 Bq/kg). These results show that the developed radiocesium detector based on PET technology is promising to detect low level radiocesium.

  8. Iterative reconstruction using a Monte Carlo based system transfer matrix for dedicated breast positron emission tomography

    SciTech Connect (OSTI)

    Saha, Krishnendu [Ohio Medical Physics Consulting, Dublin, Ohio 43017 (United States); Straus, Kenneth J.; Glick, Stephen J. [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); Chen, Yu. [Department of Radiation Oncology, Columbia University, New York, New York 10032 (United States)

    2014-08-28T23:59:59.000Z

    To maximize sensitivity, it is desirable that ring Positron Emission Tomography (PET) systems dedicated for imaging the breast have a small bore. Unfortunately, due to parallax error this causes substantial degradation in spatial resolution for objects near the periphery of the breast. In this work, a framework for computing and incorporating an accurate system matrix into iterative reconstruction is presented in an effort to reduce spatial resolution degradation towards the periphery of the breast. The GATE Monte Carlo Simulation software was utilized to accurately model the system matrix for a breast PET system. A strategy for increasing the count statistics in the system matrix computation and for reducing the system element storage space was used by calculating only a subset of matrix elements and then estimating the rest of the elements by using the geometric symmetry of the cylindrical scanner. To implement this strategy, polar voxel basis functions were used to represent the object, resulting in a block-circulant system matrix. Simulation studies using a breast PET scanner model with ring geometry demonstrated improved contrast at 45% reduced noise level and 1.5 to 3 times resolution performance improvement when compared to MLEM reconstruction using a simple line-integral model. The GATE based system matrix reconstruction technique promises to improve resolution and noise performance and reduce image distortion at FOV periphery compared to line-integral based system matrix reconstruction.

  9. Inclusive Measurements of Inelastic Electron and Positron Scattering from Unpolarized Hydrogen and Deuterium Targets

    E-Print Network [OSTI]

    The HERMES Collaboration; A. Airapetian; N. Akopov; Z. Akopov; E. C. Aschenauer; W. Augustyniak; R. Avakian; A. Avetissian; E. Avetisyan; S. Belostotski; N. Bianchi; H. P. Blok; A. Borissov; J. Bowles; V. Bryzgalov; J. Burns; M. Capiluppi; G. P. Capitani; E. Cisbani; G. Ciullo; M. Contalbrigo; P. F. Dalpiaz; W. Deconinck; R. De Leo; L. De Nardo; E. De Sanctis; M. Diefenthaler; P. Di Nezza; M. Dueren; M. Ehrenfried; G. Elbakian; F. Ellinghaus; R. Fabbri; A. Fantoni; L. Felawka; S. Frullani; D. Gabbert; G. Gapienko; V. Gapienko; F. Garibaldi; G. Gavrilov; V. Gharibyan; F. Giordano; S. Gliske; M. Golembiovskaya; C. Hadjidakis; M. Hartig; D. Hasch; G. Hill; A. Hillenbrand; M. Hoek; Y. Holler; I. Hristova; Y. Imazu; A. Ivanilov; H. E. Jackson; H. S. Jo; S. Joosten; R. Kaiser; G. Karyan; T. Keri; E. Kinney; A. Kisselev; V. Korotkov; V. Kozlov; P. Kravchenko; V. G. Krivokhijine; L. Lagamba; R. Lamb; L. Lapikas; I. Lehmann; P. Lenisa; L. A. Linden-Levy; A. Lopez Ruiz; W. Lorenzon; X. -G. Lu; X. -R. Lu; B. -Q. Ma; D. Mahon; N. C. R. Makins; S. I. Manaenkov; L. Manfre; Y. Mao; B. Marianski; A. Martinez de la Ossa; H. Marukyan; C. A. Miller; Y. Miyachi; A. Movsisyan; V. Muccifora; M. Murray; A. Mussgiller; E. Nappi; Y. Naryshkin; A. Nass; M. Negodaev; W. -D. Nowak; L. L. Pappalardo; R. Perez-Benito; N. Pickert; M. Raithel; P. E. Reimer; A. R. Reolon; C. Riedl; K. Rith; G. Rosner; A. Rostomyan; J. Rubin; D. Ryckbosch; Y. Salomatin; F. Sanftl; A. Schaefer; G. Schnell; K. P. Schueler; B. Seitz; T. -A. Shibata; V. Shutov; M. Stancari; M. Statera; E. Steffens; J. J. M. Steijger; H. Stenzel; J. Stewart; F. Stinzing; S. Taroian; A. Trzcinski; M. Tytgat; A. Vandenbroucke; Y. Van Haarlem; C. Van Hulse; D. Veretennikov; V. Vikhrov; I. Vilardi; C. Vogel; S. Wang; S. Yaschenko; H. Ye; Z. Ye; S. Yen; W. Yu; D. Zeiler; B. Zihlmann; P. Zupranski

    2011-05-02T23:59:59.000Z

    Results of inclusive measurements of inelastic electron and positron scattering from unpolarized protons and deuterons at the HERMES experiment are presented. The structure functions $F_2^p$ and $F_2^d$ are determined using a parameterization of existing data for the longitudinal-to-transverse virtual-photon absorption cross-section ratio. The HERMES results provide data in the ranges $0.006\\leq x\\leq 0.9$ and 0.1 GeV$^2\\leq Q^2\\leq$ 20 GeV$^2$, covering the transition region between the perturbative and the non-perturbative regimes of QCD in a so-far largely unexplored kinematic region. They are in agreement with existing world data in the region of overlap. The measured cross sections are used, in combination with data from other experiments, to perform fits to the photon-nucleon cross section using the functional form of the ALLM model. The deuteron-to-proton cross-section ratio is also determined.

  10. Inclusive Measurements of Inelastic Electron and Positron Scattering from Unpolarized Hydrogen and Deuterium Targets

    E-Print Network [OSTI]

    Airapetian, A; Akopov, Z; Aschenauer, E C; Augustyniak, W; Avakian, R; Avetissian, A; Avetisyan, E; Belostotski, S; Bianchi, N; Blok, H P; Borissov, A; Bowles, J; Bryzgalov, V; Burns, J; Capiluppi, M; Capitani, G P; Cisbani, E; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; Deconinck, W; De Leo, R; De Nardo, L; De Sanctis, E; Diefenthaler, M; Di Nezza, P; Dueren, M; Ehrenfried, M; Elbakian, G; Ellinghaus, F; Fabbri, R; Fantoni, A; Felawka, L; Frullani, S; Gabbert, D; Gapienko, G; Gapienko, V; Garibaldi, F; Gavrilov, G; Gharibyan, V; Giordano, F; Gliske, S; Golembiovskaya, M; Hadjidakis, C; Hartig, M; Hasch, D; Hill, G; Hillenbrand, A; Hoek, M; Holler, Y; Hristova, I; Imazu, Y; Ivanilov, A; Jackson, H E; Jo, H S; Joosten, S; Kaiser, R; Karyan, G; Keri, T; Kinney, E; Kisselev, A; Korotkov, V; Kozlov, V; Kravchenko, P; Krivokhijine, V G; Lagamba, L; Lamb, R; Lapikas, L; Lehmann, I; Lenisa, P; Linden-Levy, L A; Ruiz, A Lopez; Lorenzon, W; Lu, X -G; Lu, X -R; Ma, B -Q; Mahon, D; Makins, N C R; Manaenkov, S I; Manfre, L; Mao, Y; Marianski, B; de la Ossa, A Martinez; Marukyan, H; Miller, C A; Miyachi, Y; Movsisyan, A; Muccifora, V; Murray, M; Mussgiller, A; Nappi, E; Naryshkin, Y; Nass, A; Negodaev, M; Nowak, W -D; Pappalardo, L L; Perez-Benito, R; Pickert, N; Raithel, M; Reimer, P E; Reolon, A R; Riedl, C; Rith, K; Rosner, G; Rostomyan, A; Rubin, J; Ryckbosch, D; Salomatin, Y; Sanftl, F; Schaefer, A; Schnell, G; Schueler, K P; Seitz, B; Shibata, T -A; Shutov, V; Stancari, M; Statera, M; Steffens, E; Steijger, J J M; Stenzel, H; Stewart, J; Stinzing, F; Taroian, S; Trzcinski, A; Tytgat, M; Vandenbroucke, A; Van Haarlem, Y; Van Hulse, C; Veretennikov, D; Vikhrov, V; Vilardi, I; Vogel, C; Wang, S; Yaschenko, S; Ye, H; Ye, Z; Yen, S; Yu, W; Zeiler, D; Zihlmann, B; Zupranski, P

    2011-01-01T23:59:59.000Z

    Results of inclusive measurements of inelastic electron and positron scattering from unpolarized protons and deuterons at the HERMES experiment are presented. The structure functions $F_2^p$ and $F_2^d$ are determined using a parameterization of existing data for the longitudinal-to-transverse virtual-photon absorption cross-section ratio. The HERMES results provide data in the ranges $0.006\\leq x\\leq 0.9$ and 0.1 GeV$^2\\leq Q^2\\leq$ 20 GeV$^2$, covering the transition region between the perturbative and the non-perturbative regimes of QCD in a so-far largely unexplored kinematic region. They are in agreement with existing world data in the region of overlap. The measured cross sections are used, in combination with data from other experiments, to perform fits to the photon-nucleon cross section using the functional form of the ALLM model. The deuteron-to-proton cross-section ratio is also determined.

  11. Moessbauer and Positron Annihilation Spectroscopy Applied to WWER-1000 RPV Steels

    SciTech Connect (OSTI)

    Slugen, V.; Lipka, J. [Department of Nuclear Physics and Technology, Slovak University of Technology, Ilkovicova 3, 81219 Bratislava (Slovakia); Zeman, A. [Department of Nuclear Physics and Technology, Slovak University of Technology, Ilkovicova 3, 81219 Bratislava (Slovakia); Institute for Energy, Joint Research Centre of the European Commission, P.O. Box 2, 1755ZG Petten (Netherlands); Debarberis, L. [Institute for Energy, Joint Research Centre of the European Commission, P.O. Box 2, 1755ZG Petten (Netherlands)

    2005-04-26T23:59:59.000Z

    Moessbauer spectroscopy (MS) and Positron annihilation spectroscopy (PAS) were applied in the evaluation of the microstructure parameters and degradation processes of nuclear reactor pressure vessel (RPV) steel surveillance specimens. Study was oriented to the material investigation of Russian WWER-1000 steels (15Kh2MNFAA and 12Kh2N2MAA) with higher Ni content (1.26 wt.% in base metal and 1.7 wt.% in weld). For comparison, the WWER-440 weld metal (Sv10KhMFT) without Ni was measured too. Specimens were studied in as received form, after irradiation in LVR-15 experimental reactor to the neutron fluence F(E>0.5 MeV) = 1.47x1024 m-2s-1 and after annealing process in vacuum at 475 deg. C/2h. Changes due to different chemical composition and due to irradiation were registered using MS. Post-irradiation thermal treatment and annealing of defects was well detected by different PAS techniques. Results confirm the hypothesis that Ni affects size (decrease) and distribution (more homogeneous) of the Cu- and P-rich clusters and MxCx carbides.

  12. DC source assemblies

    DOE Patents [OSTI]

    Campbell, Jeremy B; Newson, Steve

    2013-02-26T23:59:59.000Z

    Embodiments of DC source assemblies of power inverter systems of the type suitable for deployment in a vehicle having an electrically grounded chassis are provided. An embodiment of a DC source assembly comprises a housing, a DC source disposed within the housing, a first terminal, and a second terminal. The DC source also comprises a first capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the first terminal. The DC source assembly further comprises a second capacitor having a first electrode electrically coupled to the housing, and a second electrode electrically coupled to the second terminal.

  13. Dynamic radioactive particle source

    DOE Patents [OSTI]

    Moore, Murray E.; Gauss, Adam Benjamin; Justus, Alan Lawrence

    2012-06-26T23:59:59.000Z

    A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

  14. SOURCE SELECTION INFORMATION -

    Office of Environmental Management (EM)

    on Energy and Water Development U.S. House of Representatives The Honorable Lamar Alexander Ranking Member SOURCE SELECTION INFORMATION - SEE FEDERAL ACQUISITION...

  15. SOURCE SELECTION INFORMATION -

    Energy Savers [EERE]

    on Energy and Water Development U.S. House of Representatives The Honorable Lamar Alexander SOURCE SELECTION INFORMATION - SEE FEDERAL ACQUISITION REGULATION (FAR)...

  16. SOURCE SELECTION INFORMATION -

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    SOURCE SELECTION INFORMATION - SEE FEDERAL ACQUISITION REGULATION (FAR) 2.101 AND 3.104 Department of Energy Washington, DC 20585 (enter date here, centered revised template...

  17. Publications | Advanced Photon Source

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    research at the APS. It is the official source for listing APS-related journal articles, conference proceedings and papers, dissertations, books, book chapters, technical reports,...

  18. Positron Emission Tomography (PET) Evaluation After Initial Chemotherapy and Radiation Therapy Predicts Local Control in Rhabdomyosarcoma

    SciTech Connect (OSTI)

    Dharmarajan, Kavita V., E-mail: dharmark@mskcc.org [Departments of Radiation Oncology, Pediatric Oncology, and Nuclear Medicine, Memorial Sloan-Kettering, New York, New York (United States); Wexler, Leonard H.; Gavane, Somali; Fox, Josef J.; Schoder, Heiko; Tom, Ashlyn K.; Price, Alison N.; Meyers, Paul A.; Wolden, Suzanne L. [Departments of Radiation Oncology, Pediatric Oncology, and Nuclear Medicine, Memorial Sloan-Kettering, New York, New York (United States)] [Departments of Radiation Oncology, Pediatric Oncology, and Nuclear Medicine, Memorial Sloan-Kettering, New York, New York (United States)

    2012-11-15T23:59:59.000Z

    Purpose: 18-fluorodeoxyglucose positron emission tomography (PET) is already an integral part of staging in rhabdomyosarcoma. We investigated whether primary-site treatment response characterized by serial PET imaging at specific time points can be correlated with local control. Patients and Methods: We retrospectively examined 94 patients with rhabdomyosarcoma who received initial chemotherapy 15 weeks (median) before radiotherapy and underwent baseline, preradiation, and postradiation PET. Baseline PET standardized uptake values (SUVmax) and the presence or absence of abnormal uptake (termed PET-positive or PET-negative) both before and after radiation were examined for the primary site. Local relapse-free survival (LRFS) was calculated according to baseline SUVmax, PET-positive status, and PET-negative status by the Kaplan-Meier method, and comparisons were tested with the log-rank test. Results: The median patient age was 11 years. With 3-year median follow-up, LRFS was improved among postradiation PET-negative vs PET-positive patients: 94% vs 75%, P=.02. By contrast, on baseline PET, LRFS was not significantly different for primary-site SUVmax {<=}7 vs >7 (median), although the findings suggested a trend toward improved LRFS: 96% for SUVmax {<=}7 vs 79% for SUVmax >7, P=.08. Preradiation PET also suggested a statistically insignificant trend toward improved LRFS for PET-negative (97%) vs PET-positive (81%) patients (P=.06). Conclusion: Negative postradiation PET predicted improved LRFS. Notably, 77% of patients with persistent postradiation uptake did not experience local failure, suggesting that these patients could be closely followed up rather than immediately referred for intervention. Negative baseline and preradiation PET findings suggested statistically insignificant trends toward improved LRFS. Additional study may further understanding of relationships between PET findings at these time points and outcome in rhabdomyosarcoma.

  19. Fine-Grid Calculations for Stellar Electron and Positron Capture Rates on Fe-Isotopes

    E-Print Network [OSTI]

    Jameel-Un Nabi; Abdel Nasser Tawfik

    2011-08-23T23:59:59.000Z

    The acquisition of precise and reliable nuclear data is a prerequisite to success for stellar evolution and nucleosynthesis studies. Core-collapse simulators find it challenging to generate an explosion from the collapse of the core of massive stars. It is believed that a better understanding of the microphysics of core-collapse can lead to successful results. The weak interaction processes are able to trigger the collapse and control the lepton-to-baryon ratio ($Y_{e}$) of the core material. It is suggested that the temporal variation of $Y_{e}$ within the core of a massive star has a pivotal role to play in the stellar evolution and a fine-tuning of this parameter at various stages of presupernova evolution is the key to generate an explosion. During the presupernova evolution of massive stars, isotopes of iron, mainly $^{54,55,56}$Fe, are considered to be key players in controlling $Y_{e}$ ratio via electron capture on these nuclide. Recently an improved microscopic calculation of weak interaction mediated rates for iron isotopes was introduced using the proton-neutron quasiparticle random phase approximation (pn-QRPA) theory. The pn-QRPA theory allows a microscopic \\textit{state-by-state} calculation of stellar capture rates which greatly increases the reliability of calculated rates. The results were suggestive of some fine-tuning of the $Y_{e}$ ratio during various phases of stellar evolution. Here we present for the first time the fine-grid calculation of the electron and positron capture rates on $^{54,55,56}$Fe. Core-collapse simulators may find this calculation suitable for interpolation purposes and for necessary incorporation in the stellar evolution codes.

  20. Fine-grid calculations for stellar electron and positron capture rates on Fe isotopes

    SciTech Connect (OSTI)

    Nabi, Jameel-Un, E-mail: jameel@giki.edu.pk [Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Faculty of Engineering Sciences (Pakistan)] [Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Faculty of Engineering Sciences (Pakistan); Tawfik, Abdel Nasser, E-mail: a.tawfik@eng.mti.edu.eg [MTI University, Egyptian Center for Theoretical Physics (ECTP) (Egypt)

    2013-03-15T23:59:59.000Z

    The acquisition of precise and reliable nuclear data is a prerequisite to success for stellar evolution and nucleosynthesis studies. Core-collapse simulators find it challenging to generate an explosion from the collapse of the core of massive stars. It is believed that a better understanding of the microphysics of core-collapse can lead to successful results. The weak interaction processes are able to trigger the collapse and control the lepton-to-baryon ratio (Y{sub e}) of the corematerial. It is suggested that the temporal variation of Y{sub e} within the core of a massive star has a pivotal role to play in the stellar evolution and a fine-tuning of this parameter at various stages of presupernova evolution is the key to generate an explosion. During the presupernova evolution of massive stars, isotopes of iron, mainly {sup 54-56}Fe, are considered to be key players in controlling Y{sub e} ratio via electron capture on these nuclides. Recently an improved microscopic calculation of weak-interaction-mediated rates for iron isotopes was introduced using the proton-neutron quasiparticle random-phase-approximation (pn-QRPA) theory. The pn-QRPA theory allows a microscopic state-by-state calculation of stellar capture rates which greatly increases the reliability of calculated rates. The results were suggestive of some fine-tuning of the Y{sub e} ratio during various phases of stellar evolution. Here we present for the first time the fine-grid calculation of the electron and positron capture rates on {sup 54-56}Fe. The sensitivity of the pn-QRPA calculated capture rates to the deformation parameter is also studied in this work. Core-collapse simulators may find this calculation suitable for interpolation purposes and for necessary incorporation in the stellar evolution codes.

  1. Positron annihilation studies of the AlO{sub x}/SiO{sub 2}/Si interface in solar cell structures

    SciTech Connect (OSTI)

    Edwardson, C. J.; Coleman, P. G. [Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom); Li, T.-T. A.; Cuevas, A. [College of Engineering and Computer Science, Australian National University, Canberra, ACT 0200 (Australia); Ruffell, S. [Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia)

    2012-03-01T23:59:59.000Z

    Film and film/substrate interface characteristics of 30 and 60 nm-thick AlO{sub x} films grown on Si substrates by thermal atomic layer deposition (ALD), and 30 nm-thick AlO{sub x} films by sputtering, have been probed using variable-energy positron annihilation spectroscopy (VEPAS) and Doppler-broadened spectra ratio curves. All samples were found to have an interface which traps positrons, with annealing increasing this trapping response, regardless of growth method. Thermal ALD creates an AlO{sub x}/SiO{sub x}/Si interface with positron trapping and annihilation occurring in the Si side of the SiO{sub x}/Si boundary. An induced positive charge in the Si next to the interface reduces diffusion into the oxides and increases annihilation in the Si. In this region there is a divacancy-type response (20 {+-} 2%) before annealing which is increased to 47 {+-} 2% after annealing. Sputtering seems to not produce samples with this same electrostatic shielding; instead, positron trapping occurs directly in the SiO{sub x} interface in the as-deposited sample, and the positron response to it increases after annealing as an SiO{sub 2} layer is formed. Annealing the film has the effect of lowering the film oxygen response in all film types. Compared to other structural characterization techniques, VEPAS shows larger sensitivity to differences in film preparation method and between as-deposited and annealed samples.

  2. Point defects introduced by InN alloying into In{sub x}Ga{sub 1-x}N probed using a monoenergetic positron beam

    SciTech Connect (OSTI)

    Uedono, A. [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Tsutsui, T.; Watanabe, T.; Kimura, S.; Zhang, Y. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Lozac'h, M. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Sang, L. W.; Sumiya, M. [National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Ishibashi, S. [Nanosystem Research Institute (NRI) 'RICS,' National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan)

    2013-03-28T23:59:59.000Z

    Native defects in In{sub x}Ga{sub 1-x}N (x = 0.06-0.14) grown by metal organic chemical vapor deposition were studied using a monoenergetic positron beam. Measurements of Doppler broadening spectra of the annihilation radiation as a function of incident positron energy for In{sub x}Ga{sub 1-x}N showed that vacancy-type defects were introduced with increasing InN composition, and the major defect species was identified as complexes between a cation vacancy and a nitrogen vacancy. The concentration of the divacancy, however, was found to be suppressed by Mg doping. The momentum distribution of electrons at the In{sub x}Ga{sub 1-x}N/GaN interface was close to that in defect-free GaN or In{sub x}Ga{sub 1-x}N, which was attributed to localization of positrons at the interface due to the built-in electric field, and to suppression of positron trapping by vacancy-type defects. We have also shown that the diffusion property of positrons is sensitive to an electric field near the In{sub x}Ga{sub 1-x}N/GaN interface.

  3. Radiation Source Replacement Workshop

    SciTech Connect (OSTI)

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01T23:59:59.000Z

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  4. Lithium ion sources

    E-Print Network [OSTI]

    Roy, Prabir K.

    2014-01-01T23:59:59.000Z

    HIFAN 1866 Lithium ion sources by Prabir K. Roy, Wayne G.No. DE-AC02-05CH11231. Lithium ion sources Prabir K. RoyUSA Abstract A 10.9 cm diameter lithium alumino-silicate ion

  5. Neutron sources and applications

    SciTech Connect (OSTI)

    Price, D.L. [ed.] [Argonne National Lab., IL (United States); Rush, J.J. [ed.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

    1994-01-01T23:59:59.000Z

    Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications.

  6. Photonic crystal light source

    DOE Patents [OSTI]

    Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM); Bur, James A. (Corrales, NM)

    2004-07-27T23:59:59.000Z

    A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

  7. Piezotube borehole seismic source

    DOE Patents [OSTI]

    Daley, Tom M; Solbau, Ray D; Majer, Ernest L

    2014-05-06T23:59:59.000Z

    A piezoelectric borehole source capable of permanent or semipermanent insertion into a well for uninterrupted well operations is described. The source itself comprises a series of piezoelectric rings mounted to an insulative mandrel internally sized to fit over a section of well tubing, the rings encased in a protective housing and electrically connected to a power source. Providing an AC voltage to the rings will cause expansion and contraction sufficient to create a sonic pulse. The piezoelectric borehole source fits into a standard well, and allows for uninterrupted pass-through of production tubing, and other tubing and electrical cables. Testing using the source may be done at any time, even concurrent with well operations, during standard production.

  8. Pulsed ion beam source

    DOE Patents [OSTI]

    Greenly, John B. (Lansing, NY)

    1997-01-01T23:59:59.000Z

    An improved pulsed ion beam source having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center.

  9. Collective effects of stellar winds and unidentified gamma-ray sources

    E-Print Network [OSTI]

    Diego F. Torres; Eva Domingo-Santamaria

    2006-11-11T23:59:59.000Z

    We study collective wind configurations produced by a number of massive stars, and obtain densities and expansion velocities of the stellar wind gas that is to be target, in this model, of hadronic interactions. We study the expected $\\gamma$-ray emission from these regions, considering in an approximate way the effect of cosmic ray modulation. We compute secondary particle production (electrons from knock-on interactions and electrons and positrons from charged pion decay), and solve the loss equation with ionization, synchrotron, bremsstrahlung, inverse Compton, and expansion losses. We provide examples where configurations can produce sources for GLAST satellite, and the MAGIC, HESS, or VERITAS telescopes in non-uniform ways, i.e., with or without the corresponding counterparts. We show that in all cases we studied no EGRET source is expected.

  10. Fluorodeoxyglucose Positron Emission Tomography Response and Normal Tissue Regeneration After Stereotactic Body Radiotherapy to Liver Metastases

    SciTech Connect (OSTI)

    Stinauer, Michelle A., E-mail: Michelle.Stinauer@ucdenver.edu [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Diot, Quentin; Westerly, David C.; Schefter, Tracey E.; Kavanagh, Brian D. [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States)] [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States)

    2012-08-01T23:59:59.000Z

    Purpose: To characterize changes in standardized uptake value (SUV) in positron emission tomography (PET) scans and determine the pace of normal tissue regeneration after stereotactic body radiation therapy (SBRT) for solid tumor liver metastases. Methods and Materials: We reviewed records of patients with liver metastases treated with SBRT to {>=}40 Gy in 3-5 fractions. Evaluable patients had pretreatment PET and {>=}1 post-treatment PET. Each PET/CT scan was fused to the planning computed tomography (CT) scan. The maximum SUV (SUV{sub max}) for each lesion and the total liver volume were measured on each PET/CT scan. Maximum SUV levels before and after SBRT were recorded. Results: Twenty-seven patients with 35 treated liver lesions were studied. The median follow-up was 15.7 months (range, 1.5-38.4 mo), with 5 PET scans per patient (range, 2-14). Exponential decay curve fitting (r=0.97) showed that SUV{sub max} declined to a plateau of 3.1 for controlled lesions at 5 months after SBRT. The estimated SUV{sub max} decay half-time was 2.0 months. The SUV{sub max} in controlled lesions fluctuated up to 4.2 during follow-up and later declined; this level is close to 2 standard deviations above the mean normal liver SUV{sub max} (4.01). A failure cutoff of SUV{sub max} {>=}6 is twice the calculated plateau SUV{sub max} of controlled lesions. Parenchymal liver volume decreased by 20% at 3-6 months and regenerated to a new baseline level approximately 10% below the pretreatment level at 12 months. Conclusions: Maximum SUV decreases over the first months after SBRT to plateau at 3.1, similar to the median SUV{sub max} of normal livers. Transient moderate increases in SUV{sub max} may be observed after SBRT. We propose a cutoff SUV{sub max} {>=}6, twice the baseline normal liver SUV{sub max}, to score local failure by PET criteria. Post-SBRT values between 4 and 6 would be suspicious for local tumor persistence or recurrence. The volume of normal liver reached nadir 3-6 months after SBRT and regenerated within the next 6 months.

  11. Microfabricated diffusion source

    DOE Patents [OSTI]

    Oborny, Michael C. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM); Manginell, Ronald P. (Albuquerque, NM)

    2008-07-15T23:59:59.000Z

    A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

  12. High Statistics Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–500 GeV with the Alpha Magnetic Spectrometer on the International Space Station

    E-Print Network [OSTI]

    Becker, Ulrich J.

    A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy ...

  13. First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–350 GeV

    E-Print Network [OSTI]

    Basil, A.

    A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8×10[superscript 6] positron ...

  14. (/sup 11/C)clorgyline and (/sup 11/C)-L-deprenyl and their use in measuring functional monoamine oxidase activity in the brain using positron emission tomography

    DOE Patents [OSTI]

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

    1986-04-17T23:59:59.000Z

    This invention involves a new strategy for imaging the activity of the enzyme monoamine oxidase in the living body by using /sup 11/C-labeled enzyme inhibitors which bind irreversibly to an enzyme as a result of catalysis. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

  15. ION SOURCES FOR CYCLOTRONS

    E-Print Network [OSTI]

    Clark, D.J.

    2010-01-01T23:59:59.000Z

    These utilize lasers, plasma focus, sparks, and ex­ plodingextractor voltage A plasma focus device has been used byf n a s Fig. 22: The plasma focus high charge state source

  16. A surface ionization source 

    E-Print Network [OSTI]

    Buzatu, Daniel J.

    1995-01-01T23:59:59.000Z

    The main part of the work described herein is the development and testing of a surface ionization source for use on a collinear fast beam laser spectroscopy apparatus. A description of the previously existing fast beam apparatus is given...

  17. A surface ionization source

    E-Print Network [OSTI]

    Buzatu, Daniel J.

    1995-01-01T23:59:59.000Z

    The main part of the work described herein is the development and testing of a surface ionization source for use on a collinear fast beam laser spectroscopy apparatus. A description of the previously existing fast beam apparatus is given...

  18. National Synchrotron Light Source

    ScienceCinema (OSTI)

    None

    2010-01-08T23:59:59.000Z

    A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

  19. Galactic Superluminal Sources

    E-Print Network [OSTI]

    B. A. Harmon

    1998-12-21T23:59:59.000Z

    A new class of X-ray sources was clearly established with the discovery of highly relativistic radio jets from the galactic sources GRS 1915+105 and GRO J1655-40. Both of these objects have given us a broader view of black holes and the formation of jets, yet they also show the complexity of the accretion environment near relativistic objects. The fast apparent motion of the jets, their luminosity and variability, their high energy spectrum, and approximate scaling to the behavior of active galactic nuclei, certainly warrant the description "microquasar". I present a review of the observational data on these sources, and discuss where we stand on a physical picture of GRS 1915+105 and GRO J1655-40 as taken from multi-wavelength studies. I also point out other galactic sources which share some of the properties of the microquasars, and what to look for as a high energy "signature" in future observations.

  20. Computerized Energy Information Sources

    E-Print Network [OSTI]

    Gordon, D.

    1979-01-01T23:59:59.000Z

    Many computerized files of energy- and energy conservation-related information are currently available through commercial and governmental sources such as Lockheed Information Systems, System Development Corporation, and DOE/RECON. Private...

  1. Vacancy-type defects in Er-doped GaN studied by a monoenergetic positron beam

    SciTech Connect (OSTI)

    Uedono, A.; Shaoqiang, C.; Jongwon, S.; Ito, K.; Nakamori, H.; Honda, N.; Tomita, S.; Akimoto, K.; Kudo, H. [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, 305-8573 (Japan); Ishibashi, S. [Research Institute for Computational Sciences, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, 305-8568 (Japan)

    2008-05-15T23:59:59.000Z

    A relationship between intra-4f transitions of Er and vacancy-type defects in Er-doped GaN was studied by using a monoenergetic positron beam. Doppler broadening spectra of the annihilation radiation were measured for Er-doped GaN grown by molecular beam epitaxy. A clear correlation between the defect concentration and the photoluminescence (PL) intensity was observed. The major defect species detected by positrons was identified as a Ga vacancy V{sub Ga}, and its concentration increased with increasing Er concentration [Er]. For the sample with [Er]=3.3 at. %, the maximum integrated intensity of PL was observed. The V{sub Ga} concentration was above 10{sup 18} cm{sup -3} and additional vacancies such as divacancies started to be introduced at this Er concentration. For the sample with higher [Er], the PL intensity decreased, and the mean size of vacancies decreased due to an introduction of precipitates and/or metastable phases.

  2. Positron emission tomographic imaging of tumors using monoclonal antibodies. Progress report, November 1, 1992--October 31, 1993

    SciTech Connect (OSTI)

    Zalutsky, M.R.

    1993-07-29T23:59:59.000Z

    The overall goal of this project is to be able to combine the molecular specificity of monoclonal antibodies with the imaging advantages of positron emission tomography. During the past year, were have made progress in a number of areas. This report will focus on our studies evaluating the potential of two different methods for labeling a monoclonal antibody fragment with positron-emitting F-18 both in vitro and in athymic mice bearing subcutaneous D-54 MG human glioma xenografts. The F (a b{prime}){sub 2} fragment of Me1-14, a murine egg{sub 2a} reactive with an epitope of the tumor associated proteoglycan sulfate present in gliomas and melanomas, was used. This antibody is a particular interest because of our ongoing clinical radioimmunotherapy trails using Me1--14 that could ultimately benefit from the determination of quantitative dosimetry using monoclonal antibody PET imaging. Our results demonstrated, for the first time, that MAb fragments could be labeled with F-18 with retention of immunoreactivity and affinity. Further, they show that selective and specific tumor uptake of an F-18 labeled MAb fragment can be achieved in a xenograft model in a time frame compatible with the short half life of this nuclide.

  3. Magnetron sputtering source

    DOE Patents [OSTI]

    Makowiecki, Daniel M. (Livermore, WA); McKernan, Mark A. (Livermore, CA); Grabner, R. Fred (Brentwood, CA); Ramsey, Philip B. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal.

  4. Magnetron sputtering source

    DOE Patents [OSTI]

    Makowiecki, D.M.; McKernan, M.A.; Grabner, R.F.; Ramsey, P.B.

    1994-08-02T23:59:59.000Z

    A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal. 12 figs.

  5. Field emission electron source

    DOE Patents [OSTI]

    Zettl, Alexander Karlwalter (Kensington, CA); Cohen, Marvin Lou (Berkeley, CA)

    2000-01-01T23:59:59.000Z

    A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

  6. National Synchrotron Light Source

    ScienceCinema (OSTI)

    BNL

    2009-09-01T23:59:59.000Z

    A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.

  7. ILC Vertex Tracker R&D

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    in the Mokka program for the LDC detector concept, which hasstraight track model for LDC simulation as well as simulatedsimulation is based on the LDC detector concept and a HA Z 0

  8. ILC Vertex Tracker R&D

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    DESY-TESLA-97-08. [7] M. Battaglia, A. Andreazza, M. Caccia,Meth. A (2007). [13] M. Battaglia, D. Bisello, D. Contarato,and Meth. A. [14] M. Battaglia, D. Contarato, P. Giubilato,

  9. Pulsed ion beam source

    DOE Patents [OSTI]

    Greenly, J.B.

    1997-08-12T23:59:59.000Z

    An improved pulsed ion beam source is disclosed having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center. 12 figs.

  10. COMBUSTION SOURCES OF NITROGEN COMPOUNDS

    E-Print Network [OSTI]

    Brown, Nancy J.

    2011-01-01T23:59:59.000Z

    Rasmussen, R.A. (1976). Combustion as a source of nitrousx control for stationary combustion sources. Prog. Energy,CA, March 3-4, 1977 COMBUSTION SOURCES OF NITROGEN COMPOUNDS

  11. Tsunami Information Sources: Part 3

    E-Print Network [OSTI]

    Wiegel, Robert L.

    2006-01-01T23:59:59.000Z

    Mofjeld, and A.J. Venturato, Puget Sound Tsunami Sources -Pub. Co. , 2006, pp 205-217 Puget Sound Tsunami Sources -Military Dept. , 2002, 25 pp Puget Sound Tsunami Sources -

  12. Dual source heat pump

    DOE Patents [OSTI]

    Ecker, Amir L. (Dallas, TX); Pietsch, Joseph A. (Dallas, TX)

    1982-01-01T23:59:59.000Z

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

  13. ModPET: A Novel Small-Animal PET System Positron Emission Tomography (PET) and PET/CT systems have become the gold standard for imaging

    E-Print Network [OSTI]

    Arizona, University of

    ModPET: A Novel Small-Animal PET System Positron Emission Tomography (PET) and PET/CT systems have these results to their human counterparts. Current small-animal PET scanners are very costly and complicated for Gamma-Ray Imaging, we are developing a novel small-animal PET scanner that utilizes common modular

  14. Radiation-Damage Study of a Monocrystalline Tungsten Positron Converter X. Artru, R. Kirsch, IPN, Lyon, France; R. Chehab, LAL, Orsay, France;

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Radiation-Damage Study of a Monocrystalline Tungsten Positron Converter X. Artru, R. Kirsch, IPN tested on a 0.3 mm thick tungsten monocrystal exposed dur- ing 6 months to the 30 Gev incident electron and the corresponding enhancement in pair production [1, 3]. Their use in linear colliders (LC), where high beam

  15. INEEL Source Water Assessment

    SciTech Connect (OSTI)

    Sehlke, Gerald

    2003-03-01T23:59:59.000Z

    The Idaho National Engineering and Environmental Laboratory (INEEL) covers approximately 890 mi2 and includes 12 public water systems that must be evaluated for Source water protection purposes under the Safe Drinking Water Act. Because of its size and location, six watersheds and five aquifers could potentially affect the INEEL’s drinking water sources. Based on a preliminary evaluation of the available information, it was determined that the Big Lost River, Birch Creek, and Little Lost River Watersheds and the eastern Snake River Plain Aquifer needed to be assessed. These watersheds were delineated using the United States Geologic Survey’s Hydrological Unit scheme. Well capture zones were originally estimated using the RESSQC module of the Environmental Protection Agency’s Well Head Protection Area model, and the initial modeling assumptions and results were checked by running several scenarios using Modflow modeling. After a technical review, the resulting capture zones were expanded to account for the uncertainties associated with changing groundwater flow directions, a thick vadose zone, and other data uncertainties. Finally, all well capture zones at a given facility were merged to a single wellhead protection area at each facility. A contaminant source inventory was conducted, and the results were integrated with the well capture zones, watershed and aquifer information, and facility information using geographic information system technology to complete the INEEL’s Source Water Assessment. Of the INEEL’s 12 public water systems, three systems rated as low susceptibility (EBR-I, Main Gate, and Gun Range), and the remainder rated as moderate susceptibility. No INEEL public water system rated as high susceptibility. We are using this information to develop a source water management plan from which we will subsequently implement an INEEL-wide source water management program. The results are a very robust set of wellhead protection areas that will protect the INEEL’s public water systems yet not too conservative to inhibit the INEEL from carrying out its missions.

  16. OLED area illumination source

    DOE Patents [OSTI]

    Foust, Donald Franklin (Scotia, NY); Duggal, Anil Raj (Niskayuna, NY); Shiang, Joseph John (Niskayuna, NY); Nealon, William Francis (Gloversville, NY); Bortscheller, Jacob Charles (Clifton Park, NY)

    2008-03-25T23:59:59.000Z

    The present invention relates to an area illumination light source comprising a plurality of individual OLED panels. The individual OLED panels are configured in a physically modular fashion. Each OLED panel comprising a plurality of OLED devices. Each OLED panel comprises a first electrode and a second electrode such that the power being supplied to each individual OLED panel may be varied independently. A power supply unit capable of delivering varying levels of voltage simultaneously to the first and second electrodes of each of the individual OLED panels is also provided. The area illumination light source also comprises a mount within which the OLED panels are arrayed.

  17. Sealed Radioactive Source Accountability

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1991-12-24T23:59:59.000Z

    To establish Department of Energy (DOE) interim policy and to provide guidance for sealed radioactive source accountability. The directive does not cancel any directives. Extended by DOE N 5400.10 to 12-24-93 & Extended by DOE N 5400.12 to 12-24-94.

  18. Sealed Radioactive Source Accountability

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1994-12-22T23:59:59.000Z

    This Notice extends DOE N 5400.9, Sealed Radioactive Source Accountability, of 12-24-91, until 12-24-95, unless sooner superseded or rescinded. The contents of DOE N 5400.9 will be updated and incorporated in the revised DOE O 5480.11, Radiation Protection for Occupational Workers.

  19. Funding Source Agricultural

    E-Print Network [OSTI]

    Arnold, Jonathan

    Funding Source General Research Agricultural Experiment Station Instruction Public Service,145,610$ 3,716,162DEPARTMENT OF AGRICULTURE $ 1,799,873 $ 8,322,303 $ 30,128,910 $ 0$ 85,000$ 2,127 $ 0$ 4,920,977$ 0US DEPARTMENT OF AGRICULTURE / HATCH $ 0 $ 0 $ 4,920,977 $ 15,348,823FOUNDATION

  20. Selective ion source

    DOE Patents [OSTI]

    Leung, K.N.

    1996-05-14T23:59:59.000Z

    A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P{sup +} from PH{sub 3}. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P{sup +}, As{sup +}, and B{sup +} without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices. 6 figs.

  1. Selective ion source

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA)

    1996-01-01T23:59:59.000Z

    A ion source is described wherein selected ions maybe extracted to the exclusion of unwanted ion species of higher ionization potential. Also described is a method of producing selected ions from a compound, such as P.sup.+ from PH.sub.3. The invention comprises a plasma chamber, an electron source, a means for introducing a gas to be ionized by electrons from the electron source, means for limiting electron energy from the electron source to a value between the ionization energy of the selected ion species and the greater ionization energy of an unwanted ion specie, and means for extracting the target ion specie from the plasma chamber. In one embodiment, the electrons are generated in a plasma cathode chamber immediately adjacent to the plasma chamber. A small extractor draws the electrons from the plasma cathode chamber into the relatively positive plasma chamber. The energy of the electrons extracted in this manner is easily controlled. The invention is particularly useful for doping silicon with P.sup.+, AS.sup.+, and B.sup.+ without the problematic presence of hydrogen, helium, water, or carbon oxide ions. Doped silicon is important for manufacture of semiconductors and semiconductor devices.

  2. Detecting Illicit Radioactive Sources

    SciTech Connect (OSTI)

    McDonald, Joseph C.; Coursey, Bert; Carter, Michael

    2004-11-01T23:59:59.000Z

    Specialized instruments have been developed to detect the presence of illicit radioactive sources that may be used by terrorists in radiation dispersal devices, so-called ''dirty bombs'' or improvised nuclear devices. This article discusses developments in devices to detect and measure radiation.

  3. Anomalous Higgs-top Coupling Pollution on Triple Higgs Coupling Extraction at Future High-Luminosity Electron-Positron Collider

    E-Print Network [OSTI]

    Chen Shen; Shou-hua Zhu

    2015-04-25T23:59:59.000Z

    One of the most challenging tasks for future high-luminosity electron-positron colliders is to extract Higgs triple coupling. It was proposed that this can be carried out via the precisely measuring the cross section of ZH associated production up to $0.4\\%$. In this paper, we example the possible heavy pollution from Higgs-top anomalous coupling. Our numerical results show that the pollution is small for $\\sqrt{s}_{e^+e^-}= 240 GeV$. However for the higher energy collider, pollution is sizable, which should be taken into account. We further explored the possibility to measure CP-violated Higgs top coupling, via the forward-backward asymmetry $A_{FB}$ for the process $e^+e^- \\rightarrow ZH$. The asymmetry can reach $0.7\\%$ which is comparable to the precision of cross section measurement.

  4. Optically active vacancies in GaN grown on Si substrates probed using a monoenergetic positron beam

    SciTech Connect (OSTI)

    Uedono, Akira, E-mail: uedono.akira.gb@u.tsukuba.ac.jp; Zhang, Yang; Yoshihara, Nakaaki [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Fujishima, Tatsuya; Palacios, Tomás [Microsystems Technology Laboratories, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States); Cao, Yu; Laboutin, Oleg; Johnson, Wayne [IQE, 200 John Hancock Road, Taunton, Massachusetts 01581 (United States); Ishibashi, Shoji [Nanosystem Research Institute “RICS,” National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan); Sumiya, Masatomo [Wide Bandgap Material Group, National Institute for Materials Science, Tsukuba 305-0044 (Japan)

    2014-02-24T23:59:59.000Z

    Native defects in GaN layers grown on Si substrates by metal organic chemical vapor deposition have been studied using a monoenergetic positron beam. Measurements of Doppler broadening spectra of the annihilation radiation for GaN layers showed that optically active vacancy-type defects were formed in the layers. Charge transition of the defects due to electron capture was found to occur when the layers were irradiated by photons with energy above 2.71?eV. The concentration of such defects increased after 600–800?°C annealing, but the defects have not been annealed out even at 1000?°C. They were identified as Ga-vacancy-type defects, such as complexes between Ga vacancies and carbon impurities, and the relationship between their charge transition and optical properties were discussed.

  5. Report of Snowmass 2001 Working Group E2 : Electron-positron Colliders from the $?$ to the Z

    E-Print Network [OSTI]

    Z. Zhao; G. Eigen; G. Burdman; W. Marciano; D. Hitlin; M. Mandelkern; A. Soffer; D. Cassel; L. Gibbons; K. Moenig; J. Butler; P. Kasper; R. Kutschke; P. Mackenzie; S. Pordes; R. Ray; T. Sen; D. Bettoni; R. Calabrese; C. Bloise; D. Kaplan; N. Katayama; Y. Okada; Y. Ohnishi; H. Yamamoto; A. Gritsan; S. Dytman; J. Lee; I. Shipsey; Y. Maravin; F. J. Decker; G. Hiller; P. Kim; D. Leith; S. Petrak; S. Robertson; A. Roodman; J. Seeman; M. Artuso; S. Stone; X. Lou; M. Luke; W. Johns

    2002-01-30T23:59:59.000Z

    We report on the status and plans of experiments now running or proposed for electron-positron colliders at energies between the $\\phi$ and the Z. The $e^{+}e^{-}$ B and charm factories we considered were PEP-II/BABAR, KEKB/Belle, superKEK, SuperBABAR, and CESR-c/CLEO-c. We reviewed the programs at the $\\phi$ factory at Frascati and the proposed PEP-N facility at Stanford Linear Accelerator Center. We studied the prospects for B physics with a dedicated linear collider Z factory, associated with the TESLA high energy linear collider. In all cases, we compared the physics reach of these facilities with that of alternative experiments at hadron colliders or fixed target facilities.

  6. Head on collision of multi-solitons in an electron-positron-ion plasma having superthermal electrons

    SciTech Connect (OSTI)

    Roy, Kaushik, E-mail: kaushikbolpur@rediffmail.com [Beluti M. K. M. High School, P.O. Beluti, Birbhum, West Bengal 731301 (India); Chatterjee, Prasanta, E-mail: prasantachatterjee1@rediffmail.com; Roychoudhury, Rajkumar [Department of Mathematics, Siksha Bhavana Visva Bharati, Santiniketan 731235 (India)

    2014-10-15T23:59:59.000Z

    The head-on collision and overtaking collision of four solitons in a plasma comprising superthermal electrons, cold ions, and Boltzmann distributed positrons are investigated using the extended Poincare-Lighthill-Kuo (PLK) together with Hirota's method. PLK method yields two separate Korteweg-de Vries (KdV) equations where solitons obtained from any KdV equation move along a direction opposite to that of solitons obtained from the other KdV equation, While Hirota's method gives multi-soliton solution for each KdV equation all of which move along the same direction where the fastest moving soliton eventually overtakes the other ones. We have considered here two soliton solutions obtained from Hirota's method. Phase shifts acquired by each soliton due to both head-on collision and overtaking collision are calculated analytically.

  7. Positron tomographic imaging of tumors using monoclonal antibodies. Final progress report, April 15, 1989--October 31, 1995

    SciTech Connect (OSTI)

    Zalutsky, M.R.

    1997-02-01T23:59:59.000Z

    The overall objective of this research is to develop methods for utilizing positron emission tomography (PET) to increase the clinical potential of radiolabeled monoclonal antibodies (MAbs). Enhancement of MAb tumor localization by hyperthermia also was proposed. Studies were to have been performed with both {sup 18}F and {sup 124}I; however, the lack of its availability (until quite recently) prevented experiments with {sup 124}I. Instead, two additional lines of inquiry were initiated in which they utilized aspects of the radiofluorination chemistries originally developed for MAbs for labeling chemotactic peptides and meta-iodobenzylguanidine (MIBG) analogues with {sup 18}F. This final report summarizes the original specific aims and the main research accomplishments in studies of mouse, dog and human models.

  8. Anomalous Higgs-top Coupling Pollution on Triple Higgs Coupling Extraction at Future High-Luminosity Electron-Positron Collider

    E-Print Network [OSTI]

    Shen, Chen

    2015-01-01T23:59:59.000Z

    One of the most challenging tasks for future high-luminosity electron-positron colliders is to extract Higgs triple coupling. It was proposed that this can be carried out via the precisely measuring the cross section of ZH associated production up to $0.4\\%$. In this paper, we example the possible heavy pollution from Higgs-top anomalous coupling. Our numerical results show that the pollution is quite small for $\\sqrt{s}_{e^+e^-}= 240 GeV$. However for the higher energy collider, pollution is sizable, which should be taken into account. We further explored the possibility to measure CP-violated Higgs top coupling, via the forward-backward asymmetry $A_{FB}$ for the process $e^+e^- \\rightarrow ZH$. The asymmetry can reach $0.3\\%$ which is comparable to the precision of cross section measurement.

  9. A study of defects in iron-based binary alloys by the Mössbauer and positron annihilation spectroscopies

    SciTech Connect (OSTI)

    Idczak, R., E-mail: ridczak@ifd.uni.wroc.pl; Konieczny, R.; Chojcan, J. [Institute of Experimental Physics, University of Wroc?aw, pl. M. Borna 9, 50-204 Wroc?aw (Poland)

    2014-03-14T23:59:59.000Z

    The room temperature positron annihilation lifetime spectra and {sup 57}Fe Mössbauer spectra were measured for pure Fe as well as for iron-based Fe{sub 1?x}Re{sub x}, Fe{sub 1?x}Os{sub x}, Fe{sub 1?x}Mo{sub x}, and Fe{sub 1?x}Cr{sub x} solid solutions, where x is in the range between 0.01 and 0.05. The measurements were performed in order to check if the known from the literature, theoretical calculations on the interactions between vacancies and solute atoms in iron can be supported by the experimental data. The vacancies were created during formation and further mechanical processing of the iron systems under consideration so the spectra mentioned above were collected at least twice for each studied sample synthesized in an arc furnace— after cold rolling to the thickness of about 40??m as well as after subsequent annealing at 1270?K for 2 h. It was found that only in Fe and the Fe-Cr system the isolated vacancies thermally generated at high temperatures are not observed at the room temperature and cold rolling of the materials leads to creation of another type of vacancies which were associated with edge dislocations. In the case of other cold-rolled systems, positrons detect vacancies of two types mentioned above and Mössbauer nuclei “see” the vacancies mainly in the vicinity of non-iron atoms. This speaks in favour of the suggestion that in iron matrix the solute atoms of Os, Re, and Mo interact attractively with vacancies as it is predicted by theoretical computations and the energy of the interaction is large enough for existing the pairs vacancy-solute atom at the room temperature. On the other hand, the corresponding interaction for Cr atoms is either repulsive or attractive but smaller than that for Os, Re, and Mo atoms. The latter is in agreement with the theoretical calculations.

  10. Bunch cleaning strategies and experiments at the Advanced Photon Source.

    SciTech Connect (OSTI)

    Sereno, N. S.

    1999-04-15T23:59:59.000Z

    The Advanced Photon Source (APS) design incorporated a positron accumulator ring (PAR) as part of the injector chain. In order to increase reliability and accommodate other uses of the injector, APS will run with electrons, eliminating the need for the PAR, provided another method of eliminating rf bucket pollution in the APS is found. Satellite bunches captured from an up to 30-ns-long beam from the linac need to be removed in the injector synchrotron and storage ring. The bunch cleaning method considered here relies on driving a stripline kicker with an amplitude modulated (AM) carrier signal where the carrier is at a revolution harmonic sideband corresponding to the vertical tune. The envelope waveform is phased so that all bunches except a single target bunch (eventually to be injected into the storage ring) are resonated vertically into a scraper. The kicker is designed with a large enough shunt impedance to remove satellite bunches from the injection energy of 0.4 GeV up to 1 GeV. Satellite bunch removal in the storage ring relies on the single bunch current tune shift resulting from the machine impedance. Small bunches remaining after initial preparation in the synchrotron may be removed by driving the beam vertically into a scraper using a stripline kicker operating at a sideband corresponding to the vertical tune for small current bunches. In this paper both design specifications and bunch purity measurements are reported for both the injector synchrotron and storage ring.

  11. Calibrated vapor generator source

    DOE Patents [OSTI]

    Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

    1995-09-26T23:59:59.000Z

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

  12. Calibrated vapor generator source

    DOE Patents [OSTI]

    Davies, John P. (Idaho Falls, ID); Larson, Ronald A. (Idaho Falls, ID); Goodrich, Lorenzo D. (Shelley, ID); Hall, Harold J. (Idaho Falls, ID); Stoddard, Billy D. (Idaho Falls, ID); Davis, Sean G. (Idaho Falls, ID); Kaser, Timothy G. (Idaho Falls, ID); Conrad, Frank J. (Albuquerque, NM)

    1995-01-01T23:59:59.000Z

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet.

  13. The Advanced Light Source

    SciTech Connect (OSTI)

    Jackson, A.

    1991-05-01T23:59:59.000Z

    The Advanced Light Source (ALS), a national user facility currently under construction at the Lawrence Berkeley Laboratory (LBL), is a third-generation synchrotron light source designed to produce extremely bright beams of synchrotron radiation in the energy range from a few eV to 10 keV. The design is based on a 1--1.9-GeV electron storage ring (optimized at 1.5 GeV), and utilizes special magnets, known as undulators and wigglers (collectively referred to as insertion devices), to generate the radiation. The facility is scheduled to begin operating in April 1993. In this paper we describe the progress in the design, construction, and commissioning of the accelerator systems, insertion devices, and beamlines. Companion presentations at this conference give more detail of specific components in the ALS, and describe the activities towards establishing an exciting user program. 3 figs., 2 tabs.

  14. Evaluated teletherapy source library

    DOE Patents [OSTI]

    Cox, Lawrence J. (Los Alamos, NM); Schach Von Wittenau, Alexis E. (Livermore, CA)

    2000-01-01T23:59:59.000Z

    The Evaluated Teletherapy Source Library (ETSL) is a system of hardware and software that provides for maintenance of a library of useful phase space descriptions (PSDs) of teletherapy sources used in radiation therapy for cancer treatment. The PSDs are designed to be used by PEREGRINE, the all-particle Monte Carlo dose calculation system. ETSL also stores other relevant information such as monitor unit factors (MUFs) for use with the PSDs, results of PEREGRINE calculations using the PSDs, clinical calibration measurements, and geometry descriptions sufficient for calculational purposes. Not all of this information is directly needed by PEREGRINE. It also is capable of acting as a repository for the Monte Carlo simulation history files from which the generic PSDs are derived.

  15. Spallation-neutron sources

    SciTech Connect (OSTI)

    Michaudon, A.

    1997-09-01T23:59:59.000Z

    Of particular interest for neutron-physics studies are spallation-neutron sources (SNSs) using intense proton beams with energies in the GeV range. Some SNSs already provide average fluxes of thermal and cold neutrons comparable with those of high-flux reactors. Most SNSs are pulsed with high peak fluxes that can be used with the powerful time-of-flight (TOF) method. Also, SNSs could be developed to much higher performance.

  16. High current ion source

    DOE Patents [OSTI]

    Brown, Ian G. (1088 Woodside Rd., Berkeley, CA 94708); MacGill, Robert A. (645 Kern St., Richmond, CA 94805); Galvin, James E. (2 Commodore Dr. #276, Emeryville, CA 94608)

    1990-01-01T23:59:59.000Z

    An ion source utilizing a cathode and anode for producing an electric arc therebetween. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma leaves the generation region and expands through another regon. The density profile of the plasma may be flattened using a magnetic field formed within a vacuum chamber. Ions are extracted from the plasma to produce a high current broad on beam.

  17. The European Spallation Source

    SciTech Connect (OSTI)

    Peggs, S; Eshraqi, M; Hahn, H; Jansson, A; Lindroos, M; Ponton, A; Rathsman, K; Trahern, G; Bousso, S; Calaga, R; Devanz, G; Duperrier, R D; Eguia, J; Gammino, S; Moller, S P; Oyon, C; Ruber, R.J.M.Y.

    2011-03-01T23:59:59.000Z

    The European Spallation Source (ESS) is a 5 MW, 2.5 GeV long pulse proton linac, to be built and commissioned in Lund, Sweden. The Accelerator Design Update (ADU) project phase is under way, to be completed at the end of 2012 by the delivery of a Technical Design Report. Improvements to the 2003 ESS design will be summarised, and the latest design activities will be presented.

  18. Emergent gravity from direct-action EM in a toy universe of electrons and positrons

    E-Print Network [OSTI]

    M. Ibison

    2007-10-29T23:59:59.000Z

    We sketch the derivation of a Newtonian gravity-like force emerging from a direct-action variant of classical electromagnetism. The binding energy is a consequence of maximal phase correlation of the sources mediated by approximately monochromatic direct-action fields. The resulting force then has the character of a strong version of the van der Waals force, whose superior strength can be attributed to relatively coherent primary fields (compared with the totally incoherent effects of the ZPF). The model also predicts the existence of a background having some of the character of dark energy.

  19. Capillary discharge source

    DOE Patents [OSTI]

    Bender, III, Howard Albert

    2003-11-25T23:59:59.000Z

    Debris generation from an EUV electric discharge plasma source device can be significantly reduced or essentially eliminated by encasing the electrodes with dielectric or electrically insulating material so that the electrodes are shielded from the plasma, and additionally by providing a path for the radiation to exit wherein the electrodes are not exposed to the area where the radiation is collected. The device includes: (a) a body, which is made of an electrically insulating material, that defines a capillary bore that has a proximal end and a distal end and that defines at least one radiation exit; (b) a first electrode that defines a first channel that has a first inlet end that is connected to a source of gas and a first outlet end that is in communication with the capillary bore, wherein the first electrode is positioned at the distal end of the capillary bore; (c) a second electrode that defines a second channel that has a second inlet end that is in communication with the capillary bore and an outlet end, wherein the second electrode is positioned at the proximal end of the capillary bore; and (d) a source of electric potential that is connected across the first and second electrodes, wherein radiation generated within the capillary bore is emitted through the at least one radiation exit and wherein the first electrode and second electrode are shielded from the emitted radiation.

  20. Open-Source GIS

    SciTech Connect (OSTI)

    Vatsavai, Raju [ORNL; Burk, Thomas E [University of Minnesota; Lime, Steve [Minnesota Department of Natural Resources

    2012-01-01T23:59:59.000Z

    The components making up an Open Source GIS are explained in this chapter. A map server (Sect. 30.1) can broadly be defined as a software platform for dynamically generating spatially referenced digital map products. The University of Minnesota MapServer (UMN Map Server) is one such system. Its basic features are visualization, overlay, and query. Section 30.2 names and explains many of the geospatial open source libraries, such as GDAL and OGR. The other libraries are FDO, JTS, GEOS, JCS, MetaCRS, and GPSBabel. The application examples include derived GIS-software and data format conversions. Quantum GIS, its origin and its applications explained in detail in Sect. 30.3. The features include a rich GUI, attribute tables, vector symbols, labeling, editing functions, projections, georeferencing, GPS support, analysis, and Web Map Server functionality. Future developments will address mobile applications, 3-D, and multithreading. The origins of PostgreSQL are outlined and PostGIS discussed in detail in Sect. 30.4. It extends PostgreSQL by implementing the Simple Feature standard. Section 30.5 details the most important open source licenses such as the GPL, the LGPL, the MIT License, and the BSD License, as well as the role of the Creative Commons.

  1. Annex to 7-GeV Advanced Photon Source Conceptual Design Report

    SciTech Connect (OSTI)

    Not Available

    1988-05-01T23:59:59.000Z

    The Annex to the 7-GeV Advanced Photon Source Conceptual Design Report updates the Conceptual Design Report of 1987 (CDR-87) to include the results of further optimization and changes of the design during the past year. The design changes can be summarized as affecting three areas: the accelerator system, conventional facilities, and experimental systems. Most of the changes in the accelerator system result from inclusion of a positron accumulator ring (PAR), which was added at the suggestion of the 1987 DOE Review Committee, to speed up the filling rate of the storage ring. The addition of the PAR necessitates many minor changes in the linac system, the injector synchrotron, and the low-energy beam transport lines. 63 figs., 18 tabs.

  2. The International Large Detector: Letter of Intent

    E-Print Network [OSTI]

    Abe, Toshinori; Abramowicz, Halina; Adamus, Marek; Adeva, Bernardo; Afanaciev, Konstantin; Aguilar-Saavedra, Juan Antonio; Alabau Pons, Carmen; Albrecht, Hartwig; Andricek, Ladislav; Anduze, Marc; Aplin, Steve J.; Arai, Yasuo; Asano, Masaki; Attie, David; Attree, Derek J.; Burger, Jochen; Bailey, David; Balbuena, Juan Pablo; Ball, Markus; Ballin, James; Barbi, Mauricio; Barlow, Roger; Bartels, Christoph; Bartsch, Valeria; Bassignana, Daniela; Bates, Richard; Baudot, Jerome; Bechtle, Philip; Beck, Jeannine; Beckmann, Moritz; Bedjidian, Marc; Behnke, Ties; Belkadhi, Khaled; Bellerive, Alain; Bentvelsen, Stan; Bergauer, Thomas; Berggren, C.Mikael U.; Bergholz, Matthias; Bernreuther, Werner; Besancon, Marc; Besson, Auguste; Bhattacharya, Sudeb; Bhuyan, Bipul; Biebel, Otmar; Bilki, Burak; Blair, Grahame; Blumlein, Johannes; Bo, Li; Boisvert, Veronique; Bondar, A.; Bonvicini, Giovanni; Boos, Eduard; Boudry, Vincent; Bouquet, Bernard; Bouvier, Joel; Bozovic-Jelisavcic, Ivanka; Brient, Jean-Claude; Brock, Ian; Brogna, Andrea; Buchholz, Peter; Buesser, Karsten; Bulgheroni, Antonio; Butler, John; Buttar, Craig; Buzulutskov, A.F.; Caccia, Massimo; Caiazza, Stefano; Calcaterra, Alessandro; Caldwell, Allen; Callier, Stephane L.C.; Calvo Alamillo, Enrique; Campbell, Michael; Campbell, Alan J.; Cappellini, Chiara; Carloganu, Cristina; Castro, Nuno; Castro Carballo, Maria Elena; Chadeeva, Marina; Chakraborty, Dhiman; Chang, Paoti; Charpy, Alexandre; Chen, Xun; Chen, Shaomin; Chen, Hongfang; Cheon, Byunggu; Choi, Suyong; Choudhary, B.C.; Christen, Sandra; Ciborowski, Jacek; Ciobanu, Catalin; Claus, Gilles; Clerc, Catherine; Coca, Cornelia; Colas, Paul; Colijn, Auke; Colledani, Claude; Combaret, Christophe; Cornat, Remi; Cornebise, Patrick; Corriveau, Francois; Cvach, Jaroslav; Czakon, Michal; D'Ascenzo, Nicola; Da Silva, Wilfrid; Dadoun, Olivier; Dam, Mogens; Damerell, Chris; Danilov, Mikhail; Daniluk, Witold; Daubard, Guillaume; David, Dorte; David, Jacques; De Boer, Wim; De Groot, Nicolo; De Jong, Sijbrand; De Jong, Paul; De La Taille, Christophe; De Masi, Rita; De Roeck, Albert; Decotigny, David; Dehmelt, Klaus; Delagnes, Eric; Deng, Zhi; Desch, Klaus; Dieguez, Angel; Diener, Ralf; Dima, Mihai-Octavian; Dissertori, Gunther; Dixit, Madhu S.; Dolezal, Zdenek; Dolgoshein, Boris A.; Dollan, Ralph; Dorokhov, Andrei; Doublet, Philippe; Doyle, Tony; Doziere, Guy; Dragicevic, Marko; Drasal, Zbynek; Drugakov, Vladimir; Duarte Campderros, Jordi; Dulucq, Frederic; Dumitru, Laurentiu Alexandru; Dzahini, Daniel; Eberl, Helmut; Eckerlin, Guenter; Ehrenfeld, Wolfgang; Eigen, Gerald; Eklund, Lars; Elsen, Eckhard; Elsener, Konrad; Emeliantchik, Igor; Engels, Jan; Evrard, Christophe; Fabbri, Riccardo; Faber, Gerard; Faucci Giannelli, Michele; Faus-Golfe, Angeles; Feege, Nils; Feng, Cunfeng; Ferencei, Jozef; Fernandez Garcia, Marcos; Filthaut, Frank; Fleck, Ivor; Fleischer, Manfred; Fleta, Celeste; Fleury, Julien L.; Fontaine, Jean-Charles; Foster, Brian; Fourches, Nicolas; Fouz, Mary-Cruz; Frank, Sebastian; Frey, Ariane; Frotin, Mickael; Fujii, Hirofumi; Fujii, Keisuke; Fujimoto, Junpei; Fujita, Yowichi; Fusayasu, Takahiro; Fuster, Juan; Gaddi, Andrea; Gaede, Frank; Galkin, Alexei; Galkin, Valery; Gallas, Abraham; Gallin-Martel, Laurent; Gamba, Diego; Gao, Yuanning; Garrido Beltran, Lluis; Garutti, Erika; Gastaldi, Franck; Gaur, Bakul; Gay, Pascal; Gellrich, Andreas; Genat, Jean-Francois; Gentile, Simonetta; Gerwig, Hubert; Gibbons, Lawrence; Ginina, Elena; Giraud, Julien; Giraudo, Giuseppe; Gladilin, Leonid; Goldstein, Joel; Gonzalez Sanchez, Francisco Javier; Gournaris, Filimon; Greenshaw, Tim; Greenwood, Z.D.; Grefe, Christian; Gregor, Ingrid-Maria; Grenier, Gerald Jean; Gris, Philippe; Grondin, Denis; Grunewald, Martin; Grzelak, Grzegorz; Gurtu, Atul; Haas, Tobias; Haensel, Stephan; Hajdu, Csaba; Hallermann, Lea; Han, Liang; Hansen, Peter H.; Hara, Takanori; Harder, Kristian; Hartin, Anthony; Haruyama, Tomiyoshi; Harz, Martin; Hasegawa, Yoji; Hauschild, Michael; He, Qing; Hedberg, Vincent; Hedin, David; Heinze, Isa; Helebrant, Christian; Henschel, Hans; Hensel, Carsten; Hertenberger, Ralf; Herve, Alain; Higuchi, Takeo; Himmi, Abdelkader; Hironori, Kazurayama; Hlucha, Hana; Hommels, Bart; Horii, Yasuyuki; Horvath, Dezso; Hostachy, Jean-Yves; Hou, Wei-Shu; Hu-Guo, Christine; Huang, Xingtao; Huppert, Jean Francois; Ide, Yasuhiro; Idzik, Marek; Iglesias Escudero, Carmen; Ignatenko, Alexandr; Igonkina, Olga; Ikeda, Hirokazu; Ikematsu, Katsumasa; Ikemoto, Yukiko; Ikuno, Toshinori; Imbault, Didier; Imhof, Andreas; Imhoff, Marc; Ingbir, Ronen; Inoue, Eiji

    2010-01-01T23:59:59.000Z

    The International Large Detector (ILD) is a concept for a detector at the International Linear Collider, ILC. The ILC will collide electrons and positrons at energies of initially 500 GeV, upgradeable to 1 TeV. The ILC has an ambitious physics program, which will extend and complement that of the Large Hadron Collider (LHC). A hallmark of physics at the ILC is precision. The clean initial state and the comparatively benign environment of a lepton collider are ideally suited to high precision measurements. To take full advantage of the physics potential of ILC places great demands on the detector performance. The design of ILD is driven by these requirements. Excellent calorimetry and tracking are combined to obtain the best possible overall event reconstruction, including the capability to reconstruct individual particles within jets for particle ow calorimetry. This requires excellent spatial resolution for all detector systems. A highly granular calorimeter system is combined with a central tracker which st...

  3. Absorption of Nuclear Gamma-rays on the Starlight Radiation in FR I Sources: the Case of Centaurus A

    E-Print Network [OSTI]

    L. Stawarz; F. Aharonian; S. Wagner; M. Ostrowski

    2006-07-17T23:59:59.000Z

    Several BL Lac objects are confirmed sources of variable and strongly Doppler-boosted TeV emission produced in the nuclear portions of their relativistic jets. It is more than probable, that also many of the FR I radio galaxies, believed to be the parent population of BL Lacs, are TeV sources, for which Doppler-hidden nuclear gamma-ray radiation may be only too weak to be directly observed. Here we show, however, that about one percent of the total time-averaged TeV radiation produced by the active nuclei of low-power FR I radio sources is inevitably absorbed and re-processed by photon-photon annihilation on the starlight photon field, and the following emission of the created and quickly isotropized electron-positron pairs. In the case of the radio galaxy Centaurus A, we found that the discussed mechanism can give a distinctive observable feature in the form of an isotropic gamma-ray halo. It results from the electron-positron pairs injected to the interstellar medium of the inner parts of the elliptical host by the absorption process, and upscattering starlight radiation via the inverse-Compton process mainly to the GeV-TeV photon energy range. Such a galactic gamma-ray halo is expected to possess a characteristic spectrum peaking at ~0.1 TeV photon energies, and the photon flux strong enough to be detected by modern Cherenkov Telescopes and, in the future, by GLAST. These findings should apply as well to the other nearby FR I sources.

  4. Project X: A Multi-MW Proton Source at Fermilab

    SciTech Connect (OSTI)

    Holmes, Stephen D.; /Fermilab

    2010-05-01T23:59:59.000Z

    As the Fermilab Tevatron Collider program draws to a close a strategy has emerged of an experimental program built around the high intensity frontier. The centerpiece of this program is a superconducting H- linac that will support world leading programs in long baseline neutrino experimentation and he study of rare processes. Based on technology shared with the International Linear Collider (ILC), Project X will provide multi-MW beams at 60-120 GeV from the Main Injector, simultaneous with very high intensity beams at lower energies. Project X will also support development of a Muon Collider as a uture facility at the energy frontier.

  5. SYNCHROTRON RADIATION SOURCES

    SciTech Connect (OSTI)

    HULBERT,S.L.; WILLIAMS,G.P.

    1998-07-01T23:59:59.000Z

    Synchrotron radiation is a very bright, broadband, polarized, pulsed source of light extending from the infrared to the x-ray region. It is an extremely important source of Vacuum Ultraviolet radiation. Brightness is defined as flux per unit area per unit solid angle and is normally a more important quantity than flux alone particularly in throughput limited applications which include those in which monochromators are used. It is well known from classical theory of electricity and magnetism that accelerating charges emit electromagnetic radiation. In the case of synchrotron radiation, relativistic electrons are accelerated in a circular orbit and emit electromagnetic radiation in a broad spectral range. The visible portion of this spectrum was first observed on April 24, 1947 at General Electric's Schenectady facility by Floyd Haber, a machinist working with the synchrotron team, although the first theoretical predictions were by Lienard in the latter part of the 1800's. An excellent early history with references was presented by Blewett and a history covering the development of the utilization of synchrotron radiation was presented by Hartman. Synchrotron radiation covers the entire electromagnetic spectrum from the infrared region through the visible, ultraviolet, and into the x-ray region up to energies of many 10's of kilovolts. If the charged particles are of low mass, such as electrons, and if they are traveling relativistically, the emitted radiation is very intense and highly collimated, with opening angles of the order of 1 milliradian. In electron storage rings there are three possible sources of synchrotron radiation; dipole (bending) magnets; wigglers, which act like a sequence of bending magnets with alternating polarities; and undulators, which are also multi-period alternating magnet systems but in which the beam deflections are small resulting in coherent interference of the emitted light.

  6. The European Spallation Source

    SciTech Connect (OSTI)

    Lindroos M.; Calaga R.; Bousson S.; Danared H.; Devanz G. et al

    2011-04-20T23:59:59.000Z

    In 2003 the joint European effort to design a European Spallation Source (ESS) resulted in a set of reports, and in May 2009 Lund was agreed to be the ESS site. The ESS Scandinavia office has since then worked on setting all the necessary legal and organizational matters in place so that the Design Update and construction can be started in January 2011, in collaboration with European partners. The Design Update phase is expected to end in 2012, to be followed by a construction phase, with first neutrons expected in 2018-2019.

  7. Compact ion accelerator source

    DOE Patents [OSTI]

    Schenkel, Thomas; Persaud, Arun; Kapadia, Rehan; Javey, Ali

    2014-04-29T23:59:59.000Z

    An ion source includes a conductive substrate, the substrate including a plurality of conductive nanostructures with free-standing tips formed on the substrate. A conductive catalytic coating is formed on the nanostructures and substrate for dissociation of a molecular species into an atomic species, the molecular species being brought in contact with the catalytic coating. A target electrode placed apart from the substrate, the target electrode being biased relative to the substrate with a first bias voltage to ionize the atomic species in proximity to the free-standing tips and attract the ionized atomic species from the substrate in the direction of the target electrode.

  8. Sources Sought Announcement

    National Nuclear Security Administration (NNSA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilAElectronic Input Options Gary L. Hirsch SNLMay 20102 | NationalThis SOURCES SOUGHT

  9. Plasma Sources Sci. Technol.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeedingBiomassPPPOPetroleum38 (1996) A213-A225. Printed in the UK4Sources

  10. Source Selection Guide

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently AskedEnergyIssues DOE's Nuclear EnergySmartOverview - 2015 Source Selection

  11. Source Selection Guide

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently AskedEnergyIssues DOE's Nuclear EnergySmartOverview - 2015 Source Selection

  12. Source Selection Guide

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently AskedEnergyIssues DOE's Nuclear EnergySmartOverview - 2015 Source Selection32.1

  13. Source Selection Guide

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently AskedEnergyIssues DOE's Nuclear EnergySmartOverview - 2015 Source Selection32.1

  14. Source Selection Guide

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently AskedEnergyIssues DOE's Nuclear EnergySmartOverview - 2015 Source Selection32.150.1

  15. Source Selection Guide

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently AskedEnergyIssues DOE's Nuclear EnergySmartOverview - 2015 Source Selection32.150.1

  16. Photon Source Parameters

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeeding accessPeptoid NanosheetsStudying thePhotoinducedPhoton Source

  17. Energy Sources: Renewable Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:RevisedAdvisoryStandard |inHVAC | DepartmentSource |  Why Hydrogen? * Fossil

  18. Vacancy-type defects in In{sub x}Ga{sub 1-x}N alloys probed using a monoenergetic positron beam

    SciTech Connect (OSTI)

    Uedono, A.; Watanabe, T. [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Ishibashi, S. [Nanosystem Research Institute (NRI) 'RICS,' National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Wang, X. Q.; Liu, S. T.; Chen, G.; Shen, B. [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Sang, L. W.; Sumiya, M. [Wide Bandgap Material Group, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan)

    2012-07-01T23:59:59.000Z

    Native defects in In{sub x}Ga{sub 1-x}N grown by plasma-assisted molecular beam epitaxy were probed by a monoenergetic positron beam. Doppler broadening spectra of the annihilation radiation were measured, and these were compared with results obtained using first-principles calculation. The defect concentration increased with increasing In composition x and reached the maximum at x = 0.44{approx}0.56. A clear correlation between the line-width of photoluminescence and the defect concentration was obtained. The major defect species detected by positron annihilation was identified as cation vacancies coupled with multiple nitrogen vacancies (V{sub N}s), and their introduction mechanism is discussed in terms of the strain energy due to bond-length/angle distortions and the suppression of the V{sub N} formation energy by neighboring In atoms.

  19. Advanced Photon Source Upgrade Project

    ScienceCinema (OSTI)

    Mitchell, John; Gibson, Murray; Young, Linda; Joachimiak, Andrzej

    2013-04-19T23:59:59.000Z

    Upgrade to Advanced Photon Source announced by Department Of Energy. Read more: http://go.usa.gov/ivZ

  20. Positron Emission Tomography (PET) and Positron Scanning

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeeding accessPeptoidLabPhysicsPits |RegulationsPortableDOE R&D

  1. Thulium-170 heat source

    DOE Patents [OSTI]

    Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

    1992-01-01T23:59:59.000Z

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  2. Multiple source heat pump

    DOE Patents [OSTI]

    Ecker, Amir L. (Duncanville, TX)

    1983-01-01T23:59:59.000Z

    A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

  3. Nonlinear ion-acoustic structures in a nonextensive electron–positron–ion–dust plasma: Modulational instability and rogue waves

    SciTech Connect (OSTI)

    Guo, Shimin, E-mail: gsm861@126.com [School of Mathematics and Statistics, Xi’an Jiaotong University, Xi’an, 710049 (China) [School of Mathematics and Statistics, Xi’an Jiaotong University, Xi’an, 710049 (China); Research Group MAC, Centrum Wiskunde and Informatica, Amsterdam, 1098XG (Netherlands); Mei, Liquan, E-mail: lqmei@mail.xjtu.edu.cn [School of Mathematics and Statistics, Xi’an Jiaotong University, Xi’an, 710049 (China) [School of Mathematics and Statistics, Xi’an Jiaotong University, Xi’an, 710049 (China); Center for Computational Geosciences, Xi’an Jiaotong University, Xi’an, 710049 (China); Sun, Anbang [Research Group MAC, Centrum Wiskunde and Informatica, Amsterdam, 1098XG (Netherlands)] [Research Group MAC, Centrum Wiskunde and Informatica, Amsterdam, 1098XG (Netherlands)

    2013-05-15T23:59:59.000Z

    The nonlinear propagation of planar and nonplanar (cylindrical and spherical) ion-acoustic waves in an unmagnetized electron–positron–ion–dust plasma with two-electron temperature distributions is investigated in the context of the nonextensive statistics. Using the reductive perturbation method, a modified nonlinear Schrödinger equation is derived for the potential wave amplitude. The effects of plasma parameters on the modulational instability of ion-acoustic waves are discussed in detail for planar as well as for cylindrical and spherical geometries. In addition, for the planar case, we analyze how the plasma parameters influence the nonlinear structures of the first- and second-order ion-acoustic rogue waves within the modulational instability region. The present results may be helpful in providing a good fit between the theoretical analysis and real applications in future spatial observations and laboratory plasma experiments. -- Highlights: ? Modulational instability of ion-acoustic waves in a new plasma model is discussed. ? Tsallis’s statistics is considered in the model. ? The second-order ion-acoustic rogue wave is studied for the first time.

  4. Nonlinear theory of ionic sound waves in a hot quantum-degenerate electron-positron-ion plasma

    SciTech Connect (OSTI)

    Dubinov, A. E., E-mail: dubinov-ae@yandex.ru; Sazonkin, M. A., E-mail: figma@mail.r [Sarov State Physicotechnical Institute (Russian Federation)

    2010-11-15T23:59:59.000Z

    A collisionless nonmagnetized e-p-i plasma consisting of quantum-degenerate gases of ions, electrons, and positrons at nonzero temperatures is considered. The dispersion equation for isothermal ionic sound waves is derived and analyzed, and an exact expression is obtained for the linear velocity of ionic sound. Analysis of the dispersion equation has made it possible to determine the ranges of parameters in which nonlinear solutions in the form of solitons should be sought. A nonlinear theory of isothermal ionic sound waves is developed and used for obtaining and analyzing the exact solution to the system of initial equations. Analysis has been carried out by the method of the Bernoulli pseudopotential. The ranges of phase velocities of periodic ionic sound waves and soliton velocities are determined. It is shown that in the plasma under investigation, these ranges do not overlap and that the soliton velocity cannot be lower than the linear velocity of ionic sound. The profiles of physical quantities in a periodic wave and in a soliton are constructed, as well as the dependences of the velocity of sound and the critical velocity on the ionic concentration in the plasma. It is shown that these velocities increase with the ion concentration.

  5. Novel method for hit-position reconstruction using voltage signals in plastic scintillators and its application to Positron Emission Tomography

    E-Print Network [OSTI]

    L. Raczynski; P. Moskal; P. Kowalski; W. Wislicki; T. Bednarski; P. Bialas; E. Czerwinski; L . Kaplon; A. Kochanowski; G. Korcyl; J. Kowal; T. Kozik; W. Krzemien; E. Kubicz; M. Molenda; I. Moskal; Sz. Niedzwiecki; M. Palka; M. Pawlik-Niedzwiecka; Z. Rudy; P. Salabura; N. G. Sharma; M. Silarski; A. Slomski; J. Smyrski; A. Strzelecki; A. Wieczorek; M. Zielinski; N. Zon

    2014-07-31T23:59:59.000Z

    Currently inorganic scintillator detectors are used in all commercial Time of Flight Positron Emission Tomograph (TOF-PET) devices. The J-PET collaboration investigates a possibility of construction of a PET scanner from plastic scintillators which would allow for single bed imaging of the whole human body. This paper describes a novel method of hit-position reconstruction based on sampled signals and an example of an application of the method for a single module with a 30 cm long plastic strip, read out on both ends by Hamamatsu R4998 photomultipliers. The sampling scheme to generate a vector with samples of a PET event waveform with respect to four user-defined amplitudes is introduced. The experimental setup provides irradiation of a chosen position in the plastic scintillator strip with an annihilation gamma quanta of energy 511~keV. The statistical test for a multivariate normal (MVN) distribution of measured vectors at a given position is developed, and it is shown that signals sampled at four thresholds in a voltage domain are approximately normally distributed variables. With the presented method of a vector analysis made out of waveform samples acquired with four thresholds, we obtain a spatial resolution of about 1 cm and a timing resolution of about 80 ps

  6. Role of Positron Emission Tomography in the Treatment of Occult Disease in Head-and-Neck Cancer: A Modeling Approach

    SciTech Connect (OSTI)

    Phillips, Mark H., E-mail: markp@u.washington.ed [Department of Radiation Oncology, University of Washington Medical Center, Seattle, WA (United States); Smith, Wade P. [Department of Veterans Affairs, Albany, NY (United States); Parvathaneni, Upendra; Laramore, George E. [Department of Radiation Oncology, University of Washington Medical Center, Seattle, WA (United States)

    2011-03-15T23:59:59.000Z

    Purpose: To determine under what conditions positron emission tomography (PET) imaging will be useful in decisions regarding the use of radiotherapy for the treatment of clinically occult lymph node metastases in head-and-neck cancer. Methods and Materials: A decision model of PET imaging and its downstream effects on radiotherapy outcomes was constructed using an influence diagram. This model included the sensitivity and specificity of PET, as well as the type and stage of the primary tumor. These parameters were varied to determine the optimal strategy for imaging and therapy for different clinical situations. Maximum expected utility was the metric by which different actions were ranked. Results: For primary tumors with a low probability of lymph node metastases, the sensitivity of PET should be maximized, and 50 Gy should be delivered if PET is positive and 0 Gy if negative. As the probability for lymph node metastases increases, PET imaging becomes unnecessary in some situations, and the optimal dose to the lymph nodes increases. The model needed to include the causes of certain health states to predict current clinical practice. Conclusion: The model demonstrated the ability to reproduce expected outcomes for a range of tumors and provided recommendations for different clinical situations. The differences between the optimal policies and current clinical practice are likely due to a disparity between stated clinical decision processes and actual decision making by clinicians.

  7. A Monte-Carlo simulation of the equilibrium beam polarization in ultra-high energy electron(positron) storage rings

    E-Print Network [OSTI]

    Duan, Zhe; Barber, Desmond P; Qin, Qing

    2015-01-01T23:59:59.000Z

    With the recently emerging global interest in building a next generation of circular electron-positron colliders to study the properties of the Higgs boson, and other important topics in particle physics at ultra-high beam energies, it is also important to pursue the possibility of implementing polarized beams at this energy scale. It is therefore necessary to set up simulation tools to evaluate the beam polarization at these ultra-high beam energies. In this paper, a Monte-Carlo simulation of the equilibrium beam polarization based on the Polymorphic Tracking Code(PTC) is described. The simulations are for a model storage ring with parameters similar to those of proposed circular colliders in this energy range, and they are compared with the suggestion that there are different regimes for the spin dynamics underlying the polarization of a beam in the presence of synchrotron radiation at ultra-high beam energies. In particular, it has been suggested that the so-called "correlated" crossing of spin resonances ...

  8. Dose Reconstruction Using Computational Modeling of Handling a Particular Arsenic-73/Arsenic-74 Source

    E-Print Network [OSTI]

    Stallard, Alisha M.

    2011-08-08T23:59:59.000Z

    ). The 0.511 MeV annihilation photons from positrons were included in the 74As photon source term. 22 0.0E+00 1.0E-02 2.0E-02 3.0E-02 4.0E-02 5.0E-02 6.0E-02 7.0E-02 8.0E-02 0.0E+00 2.0E-01 4.0E-01 6.0E-01 8.0E-01 1.0E+00 1.2E+00 1.4E...V (15.4%) 1204.3 keV (2.8%) 23 The source terms used for 73As photons, 74As photons, and 74As betas are shown in Figs. 26, 27 and 28, respectively. c As-73 2.3125E+10 Bq (625 mCi) photons c Disk source 1.905 cm diam / radius...

  9. Pair Production and Radiation Effects in Clouds Illuminated by Gamma Ray Sources

    E-Print Network [OSTI]

    C. D. Dermer; M. Boettcher; E. P. Liang

    2001-07-12T23:59:59.000Z

    Many classes of gamma-ray sources, such as gamma-ray bursts, blazars, Seyfert galaxies, and galactic black hole sources are surrounded by large amounts of gas and dust. X-rays and gamma-rays that traverse this material will be attenuated by Compton scattering and photoelectric absorption. One signature of an intervening scattering cloud is radiation-hardening by electrons that have been scattered and heated by the incident radiation, as illustrated by a Monte Carlo calculation. Compton scattering provides backscattered photons that will attenuate subsequent gamma rays through \\gamma\\gamma pair-production processes. We calculate the pair efficiency for a cloud illuminated by gamma-ray burst radiation. An analytic calculation of the flux of X-rays and gamma rays Thomson scattered by an intervening cloud is presented. Illuminated clouds near GRBs will form relativistic plasmas containing large numbers of electron-positron pairs that can be detected within ~1-2 days of the explosion before expanding and dissipating. Localized regions of pair annihilation radiation in the Galaxy could reveal gamma-ray sources embedded in dense clouds, or sites of past GRB explosions.

  10. In-Source Fragmentation and the Sources of Partially Tryptic...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    using three biological samples, including a standard protein mixture, a mouse brain tissue homogenate, and a mouse plasma sample. Since the in-source fragments of a...

  11. Constricted glow discharge plasma source

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA); Anders, Simone (Albany, CA); Dickinson, Michael (San Leandro, CA); Rubin, Michael (Berkeley, CA); Newman, Nathan (Winnetka, IL)

    2000-01-01T23:59:59.000Z

    A constricted glow discharge chamber and method are disclosed. The polarity and geometry of the constricted glow discharge plasma source is set so that the contamination and energy of the ions discharged from the source are minimized. The several sources can be mounted in parallel and in series to provide a sustained ultra low source of ions in a plasma with contamination below practical detection limits. The source is suitable for applying films of nitrides such as gallium nitride and oxides such as tungsten oxide and for enriching other substances in material surfaces such as oxygen and water vapor, which are difficult process as plasma in any known devices and methods. The source can also be used to assist the deposition of films such as metal films by providing low-energy ions such as argon ions.

  12. Alternative Energy Sources – Myths and Realities

    E-Print Network [OSTI]

    Youngquist, Walter

    1998-01-01T23:59:59.000Z

    Alternative Energy Sources - Myths and Realities Walterneed to think about alternative energy sources; the worlddepletion of oil? Alternative energy sources can be divided

  13. Linac Coherent Light Source Overview

    Broader source: Energy.gov [DOE]

    Take an animated tour of the Linac Coherent Light Source (LCLS). Follow the laser pulse from the injector gun all the way through to the Far Experimental Hall.

  14. Linac Coherent Light Source Overview

    SciTech Connect (OSTI)

    None

    2010-01-01T23:59:59.000Z

    Take an animated tour of the Linac Coherent Light Source (LCLS). Follow the laser pulse from the injector gun all the way through to the Far Experimental Hall.

  15. Energy Sources | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    energy, a growing source of clean, renewable American power. October 17, 2014 Passive solar design uses carefully designed overhangs and reflective coatings on windows, exterior...

  16. Linac Coherent Light Source Overview

    ScienceCinema (OSTI)

    None

    2013-05-29T23:59:59.000Z

    Take an animated tour of the Linac Coherent Light Source (LCLS). Follow the laser pulse from the injector gun all the way through to the Far Experimental Hall.

  17. Video Library | Advanced Photon Source

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    APS Brochure Annual Reports Posters Podcasts Image Gallery external site Video Library Syndicated Feeds (RSS) Now Playing: The Advanced Photon Source More videos: Building...

  18. Video Library | Advanced Photon Source

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    APS Brochure Annual Reports Posters Podcasts Image Gallery external site Video Library Syndicated Feeds (RSS) Featured Videos: Introduction to the Advanced Photon Source...

  19. Video Library | Advanced Photon Source

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Video Library Related Links: APS Colloquium APS Podcasts APS Today More videos: Introduction to the APS Physics of the Blues Now Playing: Building the Advanced Photon Source This...

  20. Detailed microscopic calculation of stellar electron and positron capture rates on $^{24}$Mg for O+Ne+Mg core simulations

    E-Print Network [OSTI]

    Jameel-Un Nabi

    2014-08-15T23:59:59.000Z

    Few white dwarfs, located in binary systems, may acquire sufficiently high mass accretion rates resulting in the burning of carbon and oxygen under nondegenerate conditions forming a O+Ne+Mg core. These O+Ne+Mg cores are gravitationally less bound than more massive progenitor stars and can release more energy due to the nuclear burning. They are also amongst the probable candidates for low entropy r-process sites. Recent observations of subluminous Type II-P supernovae (e.g., 2005cs, 2003gd, 1999br, 1997D) were able to rekindle the interest in 8 -- 10 M$_{\\odot}$ which develop O+Ne+Mg cores. Microscopic calculations of capture rates on $^{24}$Mg, which may contribute significantly to the collapse of O+Ne+Mg cores, using shell model and proton-neutron quasiparticle random phase approximation (pn-QRPA) theory, were performed earlier and comparisons made. Simulators, however, may require these capture rates on a fine scale. For the first time a detailed microscopic calculation of the electron and positron capture rates on $^{24}$Mg on an extensive temperature-density scale is presented here. This type of scale is more appropriate for interpolation purposes and of greater utility for simulation codes. The calculations are done using the pn-QRPA theory using a separable interaction. The deformation parameter, believed to be a key parameter in QRPA calculations, is adopted from experimental data to further increase the reliability of the QRPA results. The resulting calculated rates are up to a factor of 14 or more enhanced as compared to shell model rates and may lead to some interesting scenario for core collapse simulators.

  1. Ion source choices - an h- source for the high intensity neutrino source

    SciTech Connect (OSTI)

    Moehs, Douglas P.; /Fermilab; Welton, Robert F.; /SNS Project, Oak Ridge; Stockli, Martin P.; Peters, Jens; /DESY; Alessi, James; /Brookhaven

    2006-08-01T23:59:59.000Z

    The High Intensity Neutrino Source (HINS) program at Fermilab (formerly the Proton Driver) aims to develop a multi-mission linear accelerator (LINAC) capable of accelerate H{sup -} ions to 8 GeV. This paper touches on the ion source requirements for the HINS and discusses long pulse length testing of three ion sources which appear to have the capability of meeting these requirements.

  2. BSTBacterial Source Tracking Conference Proceedings

    E-Print Network [OSTI]

    BSTBacterial Source Tracking Conference Proceedings 2012 Bacterial Source Tracking State Conference Conference Proceedings Prepared by: Lucas Gregory, Texas Water Resources Institute Courtney Smith of the Science Conference Texas Water Resources Institute TR-427 June 2012 #12;#12;Texas Water Resources

  3. Particle Acceleration in Astrophysical Sources

    E-Print Network [OSTI]

    Amato, Elena

    2015-01-01T23:59:59.000Z

    Astrophysical sources are extremely efficient accelerators. Some sources emit photons up to multi-TeV energies, a signature of the presence, within them, of particles with energies much higher than those achievable with the largest accelerators on Earth. Even more compelling evidence comes from the study of Cosmic Rays, charged relativistic particles that reach the Earth with incredibly high energies: at the highest energy end of their spectrum, these subatomic particles are carrying a macroscopic energy, up to a few Joules. Here I will address the best candidate sources and mechanisms as cosmic particle accelerators. I will mainly focus on Galactic sources such as Supernova Remnants and Pulsar Wind Nebulae, which being close and bright, are the best studied among astrophysical accelerators. These sources are held responsible for most of the energy that is put in relativistic particles in the Universe, but they are not thought to accelerate particles up to the highest individual energies, $\\approx 10^{20}$ eV...

  4. Alternative Energy Sources -- An Interdisciplinary Module for...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Alternative Energy Sources -- An Interdisciplinary Module for Energy Education Alternative Energy Sources -- An Interdisciplinary Module for Energy Education Find activities...

  5. Environmental Technology Verification of Mobile Sources Control...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Environmental Technology Verification of Mobile Sources Control Technologies Environmental Technology Verification of Mobile Sources Control Technologies 2005 Diesel Engine...

  6. Microstructure and corrosion behavior of die-cast AM60B magnesium alloys in a complex salt solution: A slow positron beam study

    SciTech Connect (OSTI)

    Liu, Y.F. [Wuhan University] [Wuhan University; Qin, Q.L. [Wuhan University] [Wuhan University; Yang, W. [Wuhan University] [Wuhan University; Wen, W. [University of Kentucky] [University of Kentucky; Zhai, T. [University of Kentucky] [University of Kentucky; Yu, B. [University of Alberta] [University of Alberta; Liu, D.Y. [University of Alberta] [University of Alberta; Luo, A. [GM Research and Development Center] [GM Research and Development Center; Song, GuangLing [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    The microstructure and corrosion behavior of high pressure die-cast (HPDC) and super vacuum die-cast (SVDC) AM60B magnesium alloys were investigated in a complex salt solution using slow positron beam technique and potentiodynamic polarization tests. The experiments revealed that a CaCO3 film was formed on the surface of the alloys and that the rate of CaCO3 formation for the SVDC alloy with immersion time was slower than that of the HPDC alloy. The larger volume fraction of b-phase in the skin layer of the SVDC alloy than that of the HPDC alloy was responsible for the better corrosion resistance.

  7. International Data on Radiological Sources

    SciTech Connect (OSTI)

    Martha Finck; Margaret Goldberg

    2010-07-01T23:59:59.000Z

    ABSTRACT The mission of radiological dispersal device (RDD) nuclear forensics is to identify the provenance of nuclear and radiological materials used in RDDs and to aid law enforcement in tracking nuclear materials and routes. The application of databases to radiological forensics is to match RDD source material to a source model in the database, provide guidance regarding a possible second device, and aid the FBI by providing a short list of manufacturers and distributors, and ultimately to the last legal owner of the source. The Argonne/Idaho National Laboratory RDD attribution database is a powerful technical tool in radiological forensics. The database (1267 unique vendors) includes all sealed sources and a device registered in the U.S., is complemented by data from the IAEA Catalogue, and is supported by rigorous in-lab characterization of selected sealed sources regarding physical form, radiochemical composition, and age-dating profiles. Close working relationships with global partners in the commercial sealed sources industry provide invaluable technical information and expertise in the development of signature profiles. These profiles are critical to the down-selection of potential candidates in either pre- or post- event RDD attribution. The down-selection process includes a match between an interdicted (or detonated) source and a model in the database linked to one or more manufacturers and distributors.

  8. Three chamber negative ion source

    DOE Patents [OSTI]

    Leung, K.N.; Ehlers, K.W.; Hiskes, J.R.

    1983-11-10T23:59:59.000Z

    It is an object of this invention provide a negative ion source which efficiently provides a large flux of negatively ionized particles. This invention provides a volume source of negative ions which has a current density sufficient for magnetic fusion applications and has electrons suppressed from the output. It is still another object of this invention to provide a volume source of negative ions which can be electrostatically accelerated to high energies and subsequently neutralized to form a high energy neutral beam for use with a magnetically confined plasma.

  9. Pretreatment Staging Positron Emission Tomography/Computed Tomography in Patients With Inflammatory Breast Cancer Influences Radiation Treatment Field Designs

    SciTech Connect (OSTI)

    Walker, Gary V. [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Niikura, Naoki [Department of Breast and Endocrine Surgery, Tokai University School of Medicine, Kanagawa (Japan)] [Department of Breast and Endocrine Surgery, Tokai University School of Medicine, Kanagawa (Japan); Yang Wei [Department of Diagnostic Radiology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Diagnostic Radiology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rohren, Eric [Department of Nuclear Medicine, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Nuclear Medicine, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Valero, Vicente [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy A. [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Alvarez, Ricardo H. [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Lucci, Anthony [Department of Surgical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Surgical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ueno, Naoto T. [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A., E-mail: tbuchhol@mdanderson.org [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-08-01T23:59:59.000Z

    Purpose: Positron emission tomography/computed tomography (PET/CT) is increasingly being utilized for staging of inflammatory breast cancer (IBC). The purpose of this study was to define how pretreatment PET/CT studies affected postmastectomy radiation treatment (PMRT) planning decisions for IBC. Methods and Materials: We performed a retrospective analysis of 62 patients diagnosed with IBC between 2004 and 2009, who were treated with PMRT in our institution and who had a staging PET/CT within 3 months of diagnosis. Patients received a baseline physical examination, staging mammography, ultrasonographic examination of breast and draining lymphatics, and chest radiography; most patients also had a bone scan (55 patients), liver imaging (52 patients), breast MRI (46 patients), and chest CT (25 patients). We compared how PET/CT findings affected PMRT, assuming that standard PMRT would target the chest wall, level III axilla, supraclavicular fossa, and internal mammary chain (IMC). Any modification of target volumes, field borders, or dose prescriptions was considered a change. Results: PET/CT detected new areas of disease in 27 of the 62 patients (44%). The areas of additional disease included the breast (1 patient), ipsilateral axilla (1 patient), ipsilateral supraclavicular (4 patients), ipsilateral infraclavicular (1 patient), ipsilateral IMC (5 patients), ipsilateral subpectoral (3 patients), mediastinal (8 patients), other distant/contralateral lymph nodes (15 patients), or bone (6 patients). One patient was found to have a non-breast second primary tumor. The findings of the PET/CT led to changes in PMRT in 11 of 62 patients (17.7%). These changes included additional fields in 5 patients, adjustment of fields in 2 patients, and higher doses to the supraclavicular fossa (2 patients) and IMC (5 patients). Conclusions: For patients with newly diagnosed IBC, pretreatment PET/CT provides important information concerning involvement of locoregional lymph nodes, mediastinal lymph nodes, and unsuspected sites of distant metastasis. This information is important in the design of radiotherapy treatment fields and, therefore, we recommend that PET/CT be a component of initial staging for IBC.

  10. Outcomes of Positron Emission Tomography-Staged Clinical N3 Breast Cancer Treated With Neoadjuvant Chemotherapy, Surgery, and Radiotherapy

    SciTech Connect (OSTI)

    Park, Hae Jin [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Shin, Kyung Hwan, E-mail: radiat@ncc.re.kr [Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Cho, Kwan Ho [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Park, In Hae; Lee, Keun Seok; Ro, Jungsil; Jung, So-Youn; Lee, Seeyoun; Kim, Seok Won; Kang, Han-Sung [Center for Breast Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Chie, Eui Kyu; Ha, Sung Whan [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2011-12-01T23:59:59.000Z

    Purpose: To evaluate the treatment outcome and efficacy of regional lymph node irradiation after neoadjuvant chemotherapy (NCT) and surgery in positron emission tomography (PET)-positive clinical N3 (cN3) breast cancer patients. Methods and Materials: A total of 55 patients with ipsilateral infraclavicular (ICL), internal mammary (IMN), or supraclavicular (SCL) lymph node involvement in the absence of distant metastases, as revealed by an initial PET scan, were retrospectively analyzed. The clinical nodal stage at diagnosis (2002 AJCC) was cN3a in 14 patients (26%), cN3b in 12 patients (22%), and cN3c in 29 patients (53%). All patients were treated with NCT, followed by mastectomy or breast-conserving surgery and subsequent radiotherapy (RT) with curative intent. Results: At the median follow-up of 38 months (range, 9-80 months), 20 patients (36%) had developed treatment failures, including distant metastases either alone or combined with locoregional recurrences that included one ipsilateral breast recurrence (IBR), six regional failures (RF), and one case of combined IBR and RF. Only 3 patients (5.5%) exhibited treatment failure at the initial PET-positive clinical N3 lymph node. The 5-year locoregional relapse-free survival, disease-free survival (DFS), and overall survival rates were 80%, 60%, and 79%, respectively. RT delivered to PET-positive IMN regions in cN3b patients and at higher doses ({>=}55 Gy) to SCL regions in cN3c patients was not associated with improved 5-year IMN/SCL relapse-free survival or DFS. Conclusion: NCT followed by surgery and RT, including the regional lymph nodes, resulted in excellent locoregional control for patients with PET-positive cN3 breast cancer. The primary treatment failure in this group was due to distant metastasis rather than RF. Neither higher-dose RT directed at PET-positive SCL nodes nor coverage of PET-positive IMN nodes was associated with additional gains in locoregional control or DFS.

  11. Radiation source with shaped emission

    DOE Patents [OSTI]

    Kubiak, Glenn D.; Sweatt, William C.

    2003-05-13T23:59:59.000Z

    Employing a source of radiation, such as an electric discharge source, that is equipped with a capillary region configured into some predetermined shape, such as an arc or slit, can significantly improve the amount of flux delivered to the lithographic wafers while maintaining high efficiency. The source is particularly suited for photolithography systems that employs a ringfield camera. The invention permits the condenser which delivers critical illumination to the reticle to be simplified from five or more reflective elements to a total of three or four reflective elements thereby increasing condenser efficiency. It maximizes the flux delivered and maintains a high coupling efficiency. This architecture couples EUV radiation from the discharge source into a ring field lithography camera.

  12. Next Generation Light Source Workshops

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Next Generation Light Source Workshops A series of workshops will be held in late August with the goal of refining the scientific drivers for the facility and translating the...

  13. THE ONLY SOURCE OF ENERGY

    E-Print Network [OSTI]

    Calvin, Genevieve J.

    2011-01-01T23:59:59.000Z

    past due that we use the sun's energy on a current basis andof photosynthesis of energy (the sun) still of mil Teniaenergy farm" with the sunshine as the source. The sugar cane captures the sun,

  14. Exceptions to ignition source controls

    SciTech Connect (OSTI)

    SCHLOSSER, R.L.

    2003-03-01T23:59:59.000Z

    This document provides a basis for acceptance of risks associated with equipment that does not fully comply with the ignition source control requirements as they will be applied by the Technical Safety Requirements prepared to implement the documented safety analysis.

  15. Optical Continuum Sources in Gravitationally Lensed Quasars

    E-Print Network [OSTI]

    L. J. Goicoechea; D. Alcalde; V. N. Shalyapin

    2002-10-30T23:59:59.000Z

    We review some techniques to study the nature and size of the optical continuum sources in multiple QSOs. We focus on the source originating the events with several months timescale (the rapid variability source) as well as the source that is responsible for the non-variable background component (the background source). The techniques are used to study both the rapid variability source in Q0957+561 and the main (compact) background source in Q2237+0305.

  16. Measurement of high-Q2 neutral current deep inelastic e+p scattering cross sections with a longitudinally polarised positron beam at HERA

    E-Print Network [OSTI]

    ZEUS Collaboration; H. Abramowicz; I. Abt; L. Adamczyk; M. Adamus; R. Aggarwal; S. Antonelli; P. Antonioli; A. Antonov; M. Arneodo; O. Arslan; V. Aushev; Y. Aushev; O. Bachynska; A. Bamberger; A. N. Barakbaev; G. Barbagli; G. Bari; F. Barreiro; N. Bartosik; D. Bartsch; M. Basile; O. Behnke; J. Behr; U. Behrens; L. Bellagamba; A. Bertolin; S. Bhadra; M. Bindi; C. Blohm; V. Bokhonov; T. Bold; K. Bondarenko; E. G. Boos; K. Borras; D. Boscherini; D. Bot; I. Brock; E. Brownson; R. Brugnera; N. Brummer; A. Bruni; G. Bruni; B. Brzozowska; P. J. Bussey; B. Bylsma; A. Caldwell; M. Capua; R. Carlin; C. D. Catterall; S. Chekanov; J. Chwastowski; J. Ciborowski; R. Ciesielski; L. Cifarelli; F. Cindolo; A. Contin; A. M. Cooper-Sarkar; N. Coppola; M. Corradi; F. Corriveau; M. Costa; G. D'Agostini; F. Dal Corso; J. del Peso; R. K. Dementiev; S. De Pasquale; M. Derrick; R. C. E. Devenish; D. Dobur; B. A. Dolgoshein; G. Dolinska; A. T. Doyle; V. Drugakov; L. S. Durkin; S. Dusini; Y. Eisenberg; P. F. Ermolov; A. Eskreys; S. Fang; S. Fazio; J. Ferrando; M. I. Ferrero; J. Figiel; B. Foster; G. Gach; A. Galas; E. Gallo; A. Garfagnini; A. Geiser; I. Gialas; A. Gizhko; L. K. Gladilin; D. Gladkov; C. Glasman; O. Gogota; Yu. A. Golubkov; P. Gottlicher; I. Grabowska-Bold; J. Grebenyuk; I. Gregor; G. Grigorescu; G. Grzelak; O. Gueta; M. Guzik; C. Gwenlan; T. Haas; W. Hain; R. Hamatsu; J. C. Hart; H. Hartmann; G. Hartner; E. Hilger; D. Hochman; R. Hori; A. Huttmann; Z. A. Ibrahim; Y. Iga; R. Ingbir; M. Ishitsuka; H. -P. Jakob; F. Januschek; T. W. Jones; M. Jungst; I. Kadenko; B. Kahle; S. Kananov; T. Kanno; U. Karshon; F. Karstens; I. I. Katkov; M. Kaur; P. Kaur; A. Keramidas; L. A. Khein; J. Y. Kim; D. Kisielewska; S. Kitamura; R. Klanner; U. Klein; E. Koffeman; N. Kondrashova; O. Kononenko; P. Kooijman; Ie. Korol; I. A. Korzhavina; A. Kotanski; U. Kotz; H. Kowalski; O. Kuprash; M. Kuze; A. Lee; B. B. Levchenko; A. Levy; V. Libov; S. Limentani; T. Y. Ling; M. Lisovyi; E. Lobodzinska; W. Lohmann; B. Lohr; E. Lohrmann; K. R. Long; A. Longhin; D. Lontkovskyi; O. Yu. Lukina; J. Maeda; S. Magill; I. Makarenko; J. Malka; R. Mankel; A. Margotti; G. Marini; J. F. Martin; A. Mastroberardino; M. C. K. Mattingly; I. -A. Melzer-Pellmann; S. Mergelmeyer; S. Miglioranzi; F. Mohamad Idris; V. Monaco; A. Montanari; J. D. Morris; K. Mujkic; B. Musgrave; K. Nagano; T. Namsoo; R. Nania; A. Nigro; Y. Ning; T. Nobe; D. Notz; R. J. Nowak; A. E. Nuncio-Quiroz; B. Y. Oh; N. Okazaki; K. Olkiewicz; Yu. Onishchuk; K. Papageorgiu; A. Parenti; E. Paul; J. M. Pawlak; B. Pawlik; P. G. Pelfer; A. Pellegrino; W. Perlanski; H. Perrey; K. Piotrzkowski; P. Plucinski; N. S. Pokrovskiy; A. Polini; A. S. Proskuryakov; M. Przybycien; A. Raval; D. D. Reeder; B. Reisert; Z. Ren; J. Repond; Y. D. Ri; A. Robertson; P. Roloff; I. Rubinsky; M. Ruspa; R. Sacchi; U. Samson; G. Sartorelli; A. A. Savin; D. H. Saxon; M. Schioppa; S. Schlenstedt; P. Schleper; W. B. Schmidke; U. Schneekloth; V. Schonberg; T. Schorner-Sadenius; J. Schwartz; F. Sciulli; L. M. Shcheglova; R. Shehzadi; S. Shimizu; I. Singh; I. O. Skillicorn; W. Slominski; W. H. Smith; V. Sola; A. Solano; D. Son; V. Sosnovtsev; A. Spiridonov; H. Stadie; L. Stanco; N. Stefaniuk; A. Stern; T. P. Stewart; A. Stifutkin; P. Stopa; S. Suchkov; G. Susinno; L. Suszycki; J. Sztuk-Dambietz; D. Szuba; J. Szuba; A. D. Tapper; E. Tassi; J. Terron; T. Theedt; H. Tiecke; K. Tokushuku; J. Tomaszewska; V. Trusov; T. Tsurugai; M. Turcato; O. Turkot; T. Tymieniecka; M. Vazquez; A. Verbytskyi; O. Viazlo; N. N. Vlasov; R. Walczak; W. A. T. Wan Abdullah; J. J. Whitmore; K. Wichmann; L. Wiggers; M. Wing; M. Wlasenko; G. Wolf; H. Wolfe; K. Wrona; A. G. Yagues-Molina; S. Yamada; Y. Yamazaki; R. Yoshida; C. Youngman; O. Zabiegalov; A. F. . Zarnecki; L. Zawiejski; O. Zenaiev; W. Zeuner; B. O. Zhautykov; N. Zhmak; A. Zichichi; Z. Zolkapli; D. S. Zotkin

    2014-05-12T23:59:59.000Z

    Measurements of neutral current cross sections for deep inelastic scattering in e+p collisions at HERA with a longitudinally polarised positron beam are presented. The single-differential cross-sections d(sigma)/dQ2, d(sigma)/dx and d(sigma)/dy and the reduced cross-section were measured in the kinematic region Q2 > 185 GeV2 and y < 0.9, where Q2 is the four-momentum transfer squared, x the Bjorken scaling variable, and y the inelasticity of the interaction. The measurements were performed separately for positively and negatively polarised positron beams. The measurements are based on an integrated luminosity of 135.5 pb-1 collected with the ZEUS detector in 2006 and 2007 at a centre-of-mass energy of 318 GeV. The structure functions F3 and F3(gamma)Z were determined by combining the e+p results presented in this paper with previously published e-p neutral current results. The asymmetry parameter A+ is used to demonstrate the parity violation predicted in electroweak interactions. The measurements are well described by the predictions of the Standard Model.

  17. High-Mass Drell-Yan Cross-Section and Search for New Phenomena in Multi-Electron/Positron Final States with the ATLAS Detector

    E-Print Network [OSTI]

    Wollstadt, Simon

    The Standard Model of particle physics is a very successful theory which describes nearly all known processes of particle physics very precisely. Nevertheless, there are several observations which cannot be explained within the existing theory. In this thesis, two analyses with high energy electrons and positrons using data of the ATLAS detector are presented. One, probing the Standard Model of particle physics and another searching for phenomena beyond the Standard Model. The production of an electron-positron pair via the Drell-Yan process leads to a very clean signature in the detector with low background contributions. This allows for a very precise measurement of the cross-section and can be used as a precision test of perturbative quantum chromodynamics (pQCD) where this process has been calculated at next-to-next-to-leading order (NNLO). The invariant mass spectrum $m_{ee}$ is sensitive to parton distribution functions (PFDs), in particular to the poorly known distribution of antiquarks at large moment...

  18. Vacancy-type defects in In{sub x}Ga{sub 1?x}N grown on GaN templates probed using monoenergetic positron beams

    SciTech Connect (OSTI)

    Uedono, Akira [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Watanabe, Tomohito; Kimura, Shogo; Zhang, Yang; Lozac'h, Mickael [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Sang, Liwen; Sumiya, Masatomo [Wide Bandgap Material Group, National Institute for Materials Science, Tsukuba 305-0044 (Japan); Ishibashi, Shoji [Nanosystem Research Institute (NRI) “RICS,” National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Oshima, Nagayasu; Suzuki, Ryoichi [Research Institute of Instrumentation Frontier, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan)

    2013-11-14T23:59:59.000Z

    Native defects in In{sub x}Ga{sub 1?x}N layers grown by metalorganic chemical vapor deposition were studied using monoenergetic positron beams. Measurements of Doppler broadening spectra of the annihilation radiation and lifetime spectra of positrons for a 200-nm-thick In{sub 0.13}Ga{sub 0.87}N layer showed that vacancy-type defects were introduced by InN alloying, and the major species of such defects was identified as complexes between a cation vacancy and nitrogen vacancies. The presence of the defects correlated with lattice relaxation of the In{sub 0.13}Ga{sub 0.87}N layer and the increase in photon emissions from donor-acceptor-pair recombination. The species of native defects in In{sub 0.06}Ga{sub 0.94}N layers was the same but its concentration was decreased by decreasing the InN composition. With the layer thickness increased from 120?nm to 360?nm, a defect-rich region was introduced in the subsurface region (<160?nm), which can be associated with layer growth with the relaxation of compressive stress.

  19. Apparatus and method for preparing oxygen-15 labeled water H{sub 2}[{sup 15}O] in an injectable form for use in positron emission tomography

    DOE Patents [OSTI]

    Ferrieri, R.A.; Schlyer, D.J.; Alexoff, D.

    1996-01-09T23:59:59.000Z

    A handling and processing apparatus is revealed for preparing Oxygen-15 labeled water (H{sub 2}[{sup 15}O]) in injectable form for use in Positron Emission Tomography from preferably H{sub 2}[{sup 15}O] produced by irradiating a flowing gas target of nitrogen and hydrogen. The apparatus includes a collector for receiving and directing a gas containing H{sub 2}[{sup 15}O] gas and impurities, mainly ammonia (NH{sub 3}) gas into sterile water to trap the H{sub 2}[{sup 15}O] and form ammonium (NH{sub 4}{sup +}) in the sterile water. A device for displacing the sterile water containing H{sub 2}[{sup 15}O] and NH{sub 4}{sup +} through a cation resin removes NH{sub 4}{sup +} from the sterile water. A device for combining the sterile water containing H{sub 2}[{sup 15}O] with a saline solution produces an injectable solution. Preferably, the apparatus includes a device for delivering the solution to a syringe for injection into a patient. Also, disclosed is a method for preparing H{sub 2}[{sup 15}O] in injectable form for use in Positron Emission Tomography in which the method neither requires isotopic exchange reaction nor application of high temperature. 7 figs.

  20. Multilevel cascade voltage source inverter with seperate DC sources

    DOE Patents [OSTI]

    Peng, Fang Zheng (Knoxville, TN); Lai, Jih-Sheng (Blacksburg, VA)

    2002-01-01T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  1. Multilevel cascade voltage source inverter with seperate DC sources

    DOE Patents [OSTI]

    Peng, Fang Zheng (Oak Ridge, TN); Lai, Jih-Sheng (Knoxville, TN)

    1997-01-01T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  2. Multilevel cascade voltage source inverter with seperate DC sources

    DOE Patents [OSTI]

    Peng, Fang Zheng; Lai, Jih-Sheng

    2001-04-03T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  3. Multilevel cascade voltage source inverter with separate DC sources

    DOE Patents [OSTI]

    Peng, F.Z.; Lai, J.S.

    1997-06-24T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations. 15 figs.

  4. 4th Generation ECR Ion Sources

    E-Print Network [OSTI]

    Lyneis, Claude M.

    2010-01-01T23:59:59.000Z

    4th Generation ECR Ion Sources Claude M Lyneis, D. Leitner,to developing a 4 th generation ECR ion source with an RFover current 3 rd generation ECR ion sources, which operate

  5. A global sourcing strategy for durable tooling

    E-Print Network [OSTI]

    Vasovski, Steven

    2006-01-01T23:59:59.000Z

    Competitive pressures in manufacturing industries have led to an increased utilization of strategic sourcing initiatives: among them is low cost sourcing. While low cost sourcing has been used extensively for direct ...

  6. MODELING, SIMULATION AND OPTIMIZATION OF GROUND SOURCE

    E-Print Network [OSTI]

    MODELING, SIMULATION AND OPTIMIZATION OF GROUND SOURCE HEAT PUMP SYSTEMS By MUHAMMAD HAIDER KHAN AND OPTIMIZATION OF GROUND SOURCE HEAT PUMP SYSTEMS Thesis Approved..................................................................................................................... 1 1.1 Overview of Ground Source Heat Pump Systems.............................................. 1 1

  7. Source selection of agricultural journalists in Texas

    E-Print Network [OSTI]

    Banks, Penelope Jean

    1998-01-01T23:59:59.000Z

    Journalists rely on sources in their daily routines, and the sources they choose affect news content over time. Agricultural journalists are no exception. Eleven agricultural journalists in Texas were studied to determine what types of sources...

  8. Major Source Permits (District of Columbia)

    Broader source: Energy.gov [DOE]

    The District reviews designs for new pollution sources and design modifications for existing sources. Permits are issued to allow sources to emit limited and specified amounts of pollution as...

  9. Advanced Light Source Activity Report 2005

    E-Print Network [OSTI]

    Tamura Ed., Lori S.

    2010-01-01T23:59:59.000Z

    upgrade on the Advanced Light Source," Nucl. Instrum. Meth.n photoemission at the Advanced Light Source," Radiât. Phys.high-pressure studies at the Advanced Light Source w i t h a

  10. Compact portable electric power sources

    SciTech Connect (OSTI)

    Fry, D.N.; Holcomb, D.E.; Munro, J.K.; Oakes, L.C.; Matson, M.J.

    1997-02-01T23:59:59.000Z

    This report provides an overview of recent advances in portable electric power source (PEPS) technology and an assessment of emerging PEPS technologies that may meet US Special Operations Command`s (SOCOM) needs in the next 1--2- and 3--5-year time frames. The assessment was performed through a literature search and interviews with experts in various laboratories and companies. Nineteen PEPS technologies were reviewed and characterized as (1) PEPSs that meet SOCOM requirements; (2) PEPSs that could fulfill requirements for special field conditions and locations; (3) potentially high-payoff sources that require additional R and D; and (4) sources unlikely to meet present SOCOM requirements. 6 figs., 10 tabs.

  11. Materials for spallation neutron sources

    SciTech Connect (OSTI)

    Sommer, W.F.; Daemen, L.L. [comps.

    1996-03-01T23:59:59.000Z

    The Workshop on Materials for Spallation Neutron Sources at the Los Alamos Neutron Science Center, February 6 to 10, 1995, gathered scientists from Department of Energy national laboratories, other federal institutions, universities, and industry to discuss areas in which work is needed, successful designs and use of materials, and opportunities for further studies. During the first day of the workshop, speakers presented overviews of current spallation neutron sources. During the next 3 days, seven panels allowed speakers to present information on a variety of topics ranging from experimental and theoretical considerations on radiation damage to materials safety issues. An attempt was made to identify specific problems that require attention within the context of spallation neutron sources. This proceedings is a collection of summaries from the overview sessions and the panel presentations.

  12. Miniature x-ray source

    DOE Patents [OSTI]

    Trebes, James E. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA)

    2000-01-01T23:59:59.000Z

    A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

  13. Miniature x-ray source

    DOE Patents [OSTI]

    Trebes, James E. (Livermore, CA); Stone, Gary F. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA); Chornenky, Victor I. (Minnetonka, MN)

    2002-01-01T23:59:59.000Z

    A miniature x-ray source capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature x-ray source comprises a compact vacuum tube assembly containing a cathode, an anode, a high voltage feedthru for delivering high voltage to the anode, a getter for maintaining high vacuum, a connection for an initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is highly x-ray transparent and made, for example, from boron nitride. The compact size and potential for remote operation allows the x-ray source, for example, to be placed adjacent to a material sample undergoing analysis or in proximity to the region to be treated for medical applications.

  14. SOURCE PHENOMENOLOGY EXPERIMENTS IN ARIZONA

    SciTech Connect (OSTI)

    Jessie L. Bonner; Brian Stump; Mark Leidig; Heather Hooper; Xiaoning (David) Yang; Rongmao Zhou; Tae Sung Kim; William R. Walter; Aaron Velasco; Chris Hayward; Diane Baker; C. L. Edwards; Steven Harder; Travis Glenn; Cleat Zeiler; James Britton; James F. Lewkowicz

    2005-09-30T23:59:59.000Z

    The Arizona Source Phenomenology Experiments (SPE) have resulted in an important dataset for the nuclear monitoring community. The 19 dedicated single-fired explosions and multiple delay-fired mining explosions were recorded by one of the most densely instrumented accelerometer and seismometer arrays ever fielded, and the data have already proven useful in quantifying confinement and excitation effects for the sources. It is very interesting to note that we have observed differences in the phenomenology of these two series of explosions resulting from the differences between the relatively slow (limestone) and fast (granodiorite) media. We observed differences at the two SPE sites in the way the rock failed during the explosions, how the S-waves were generated, and the amplitude behavior as a function of confinement. Our consortium's goal is to use the synergy of the multiple datasets collected during this experiment to unravel the phenomenological differences between the two emplacement media. The data suggest that the main difference between single-fired chemical and delay-fired mining explosion seismograms at regional distances is the increased surface wave energy for the latter source type. The effect of the delay-firing is to decrease the high-frequency P-wave amplitudes while increasing the surface wave energy because of the longer source duration and spall components. The results suggest that the single-fired explosions are surrogates for nuclear explosions in higher frequency bands (e.g., 6-8 Hz Pg/Lg discriminants). We have shown that the SPE shots, together with the mining explosions, are efficient sources of S-wave energy, and our next research stage is to postulate the possible sources contributing to the shear-wave energy.

  15. The International Large Detector: Letter of Intent

    E-Print Network [OSTI]

    The ILD Concept Group

    2010-06-17T23:59:59.000Z

    The International Large Detector (ILD) is a concept for a detector at the International Linear Collider, ILC. The ILC will collide electrons and positrons at energies of initially 500 GeV, upgradeable to 1 TeV. The ILC has an ambitious physics program, which will extend and complement that of the Large Hadron Collider (LHC). A hallmark of physics at the ILC is precision. The clean initial state and the comparatively benign environment of a lepton collider are ideally suited to high precision measurements. To take full advantage of the physics potential of ILC places great demands on the detector performance. The design of ILD is driven by these requirements. Excellent calorimetry and tracking are combined to obtain the best possible overall event reconstruction, including the capability to reconstruct individual particles within jets for particle ow calorimetry. This requires excellent spatial resolution for all detector systems. A highly granular calorimeter system is combined with a central tracker which stresses redundancy and efficiency. In addition, efficient reconstruction of secondary vertices and excellent momentum resolution for charged particles are essential for an ILC detector. The interaction region of the ILC is designed to host two detectors, which can be moved into the beam position with a push-pull scheme. The mechanical design of ILD and the overall integration of subdetectors takes these operational conditions into account.

  16. Review: Semiconductor Quantum Light Sources

    E-Print Network [OSTI]

    Andrew J Shields

    2007-04-03T23:59:59.000Z

    Lasers and LEDs display a statistical distribution in the number of photons emitted in a given time interval. New applications exploiting the quantum properties of light require sources for which either individual photons, or pairs, are generated in a regulated stream. Here we review recent research on single-photon sources based on the emission of a single semiconductor quantum dot. In just a few years remarkable progress has been made in generating indistinguishable single-photons and entangled photon pairs using such structures. It suggests it may be possible to realise compact, robust, LED-like semiconductor devices for quantum light generation.

  17. Positron Emission Tomography/Computed Tomography-Guided Intensity-Modulated Radiotherapy for Limited-Stage Small-Cell Lung Cancer

    SciTech Connect (OSTI)

    Shirvani, Shervin M.; Komaki, Ritsuko [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Heymach, John V.; Fossella, Frank V. [Department of Thoracic/Head and Neck Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Chang, Joe Y., E-mail: jychang@mdanderson.org [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

    2012-01-01T23:59:59.000Z

    Purpose: Omitting elective nodal irradiation from planning target volumes does not compromise outcomes in patients with non-small-cell lung cancer, but whether the same is true for those with limited-stage small-cell lung cancer (LS-SCLC) is unknown. Therefore, in the present study, we sought to determine the clinical outcomes and the frequency of elective nodal failure in patients with LS-SCLC staged using positron emission tomography/computed tomography and treated with involved-field intensity-modulated radiotherapy. Methods and Materials: Between 2005 and 2008, 60 patients with LS-SCLC at our institution underwent disease staging using positron emission tomography/computed tomography before treatment using an intensity-modulated radiotherapy plan in which elective nodal irradiation was intentionally omitted from the planning target volume (mode and median dose, 45 Gy in 30 fractions; range, 40.5 Gy in 27 fractions to 63.8 Gy in 35 fractions). In most cases, concurrent platinum-based chemotherapy was administered. We retrospectively reviewed the clinical outcomes to determine the overall survival, relapse-free survival, and failure patterns. Elective nodal failure was defined as recurrence in initially uninvolved hilar, mediastinal, or supraclavicular nodes. Survival was assessed using the Kaplan-Meier method. Results: The median age of the study patients at diagnosis was 63 years (range, 39-86). The median follow-up duration was 21 months (range, 4-58) in all patients and 26 months (range, 4-58) in the survivors. The 2-year actuarial overall survival and relapse-free survival rate were 58% and 43%, respectively. Of the 30 patients with recurrence, 23 had metastatic disease and 7 had locoregional failure. We observed only one isolated elective nodal failure. Conclusions: To our knowledge, this is the first study to examine the outcomes in patients with LS-SCLC staged with positron emission tomography/computed tomography and treated with definitive intensity-modulated radiotherapy. In these patients, elective nodal irradiation can be safely omitted from the planning target volume for the purposes of dose escalation and toxicity reduction.

  18. RECENT PROGRESS IN HEAVY ION SOURCES

    E-Print Network [OSTI]

    Clark, D.J.

    2010-01-01T23:59:59.000Z

    of hydrogen into thermonuclear fusion reactors. A summary ofFusion Plasma Sources Other sources of high charge state ions include the dense plasma in magnetic confinement thermonuclear

  19. California Nonpoint Source Program Strategy and Implementation...

    Open Energy Info (EERE)

    LibraryAdd to library Legal Document- OtherOther: California Nonpoint Source Program Strategy and Implementation Plan, 1998-2013Legal Abstract California Nonpoint Source Program...

  20. Alternative Energy Sources - An Interdisciplinary Module for...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Sources - An Interdisciplinary Module for Energy Education Alternative Energy Sources - An Interdisciplinary Module for Energy Education Below is information about the...

  1. Good Sources of Nutrients: Iron

    E-Print Network [OSTI]

    Scott, Amanda; Replogle, Jacqueline

    2008-08-28T23:59:59.000Z

    ENP-2881 08-08 Good Sources of Nutrients Iron Buenas fuentes de nutrientes Hierro La funci?n del hierro Transporta ox?geno en la sangre para que su ? cuerpo tenga energ?a Facilita crecimiento? Proporciona energ?a que ayuda a los ni?os a ? jugar y...

  2. Climate Change Major information sources

    E-Print Network [OSTI]

    ://www.ipcc.ch/ Vital Climate Graphics, at http://www.grida.no/climate/vital/ Climate Change Impacts on US, at http://www.gcrio.org/NationalAssessment/ Greenhouse Warming Prediction #12;Energy Predictions 2 Sources: Energy Information Administration (EIA); International Energy Agency (IEA) 2% growth per year, or doubling in 35 years (shortcut: 70/%=doubling) Fossil

  3. EAT SMART Sources: Heart Health

    E-Print Network [OSTI]

    -1- EAT SMART Sources: Heart Health American Dietetic Association Complete Food and Nutrition Guide and Promotion; Home and Garden Bulletin Number 252; August 1992. Heart Attach Signs, U.S. Department of Health and Human Services: National Institutes of Heart, Lung, and Blood Institute, NIH Publication No. 01

  4. Incrementally Deployable Source Address Validity

    E-Print Network [OSTI]

    Li, Jun

    ID-SAVE: Incrementally Deployable Source Address Validity Enforcement Toby Ehrenkranz ://netsec.cs.uoregon.edu #12;Ehrenkranz WiP ID-SAVE What's The Problem? While routers know which direction a packet should are unreliable ID-SAVE attacks this root cause! 1 #12;Ehrenkranz WiP ID-SAVE ID-SAVE Basics Create and maintain

  5. Focused X-ray source

    DOE Patents [OSTI]

    Piestrup, M.A.; Boyers, D.G.; Pincus, C.I.; Maccagno, P.

    1990-08-21T23:59:59.000Z

    Disclosed is an intense, relatively inexpensive X-ray source (as compared to a synchrotron emitter) for technological, scientific, and spectroscopic purposes. A conical radiation pattern produced by a single foil or stack of foils is focused by optics to increase the intensity of the radiation at a distance from the conical radiator. 8 figs.

  6. Reporting of Radioactive Sealed Sources

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2008-02-27T23:59:59.000Z

    To establish U.S. Department of Energy requirements for inventory reporting, transaction reporting, verification of reporting, and assign responsibilities for reporting of radioactive sealed sources. DOE N 251.86 extends this notice until 5-6-11. No cancellations. Canceled by DOE O 231.1B

  7. EXCEPTIONS TO IGNITION SOURCE CONTROLS

    SciTech Connect (OSTI)

    SCHLOSSER, R.L.

    2003-09-25T23:59:59.000Z

    This document provides a basis for acceptance of risks associated with equipment and materials that do not fully comply with the ignition source controls as they are applied by the Technical Safety Requirements prepared to implement the controls required by the documented safety analysis for tank farms facilities.

  8. National Synchrotron Light Source II

    ScienceCinema (OSTI)

    Steve Dierker

    2010-01-08T23:59:59.000Z

    The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

  9. Miniaturized cathodic arc plasma source

    DOE Patents [OSTI]

    Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA)

    2003-04-15T23:59:59.000Z

    A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  10. Annealing behaviors of vacancy-type defects near interfaces between metal contacts and GaN probed using a monoenergetic positron beam

    SciTech Connect (OSTI)

    Uedono, Akira, E-mail: uedono.akira.gb@u.tsukuba.ac.jp; Yoshihara, Nakaaki [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Fujishima, Tatsuya; Piedra, Daniel; Palacios, Tomás [Microsystems Technology Laboratories, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States); Ishibashi, Shoji [Nanosystem Research Institute “RICS,” National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan); Sumiya, Masatomo [Wide Bandgap Material Group, National Institute for Materials Science, Tsukuba 305-0044 (Japan); Laboutin, Oleg; Johnson, Wayne [IQE, 200 John Hancock Road, Taunton, Massachusetts 01581 (United States)

    2014-08-04T23:59:59.000Z

    Vacancy-type defects near interfaces between metal contacts and GaN grown on Si substrates by metal organic chemical vapor deposition have been studied using a monoenergetic positron beam. Measurements of Doppler broadening spectra of the annihilation radiation for Ti-deposited GaN showed that optically active vacancy-type defects were introduced below the Ti/GaN interface after annealing at 800?°C. Charge transition of those defects due to electron capture was observed and was found to correlate with a yellow band in the photoluminescence spectrum. The major defect species was identified as vacancy clusters such as three to five Ga-vacancies coupled with multiple nitrogen-vacancies. The annealing behaviors of vacancy-type defects in Ti-, Ni-, and Pt-deposited GaN were also examined.

  11. National Synchrotron Light Source annual report 1991

    SciTech Connect (OSTI)

    Hulbert, S.L.; Lazarz, N.N. (eds.)

    1992-04-01T23:59:59.000Z

    This report contains abstracts from research conducted at the national synchrotron light source. (LSP)

  12. Best Management Practice #14: Alternative Water Sources

    Broader source: Energy.gov [DOE]

    Many federal facilities may have water uses that can be met with non-potable water from alternative water sources. Potentially available alternative water sources for Federal sources include municipal-supplied reclaimed water, treated gray water from on-site sanitary sources, and storm water.

  13. National Synchrotron Light Source Activity Report 1998

    SciTech Connect (OSTI)

    Rothman, Eva

    1999-05-01T23:59:59.000Z

    National Synchrotron Light Source Activity Report for period October 1, 1997 through September 30, 1998

  14. X-ray lithography source

    DOE Patents [OSTI]

    Piestrup, Melvin A. (Woodside, CA); Boyers, David G. (Mountain View, CA); Pincus, Cary (Sunnyvale, CA)

    1991-01-01T23:59:59.000Z

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

  15. X-ray lithography source

    DOE Patents [OSTI]

    Piestrup, M.A.; Boyers, D.G.; Pincus, C.

    1991-12-31T23:59:59.000Z

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and eliminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an excellent moderate-priced X-ray source for lithography. 26 figures.

  16. Increased security through open source

    E-Print Network [OSTI]

    Jaap-Henk Hoepman; Bart Jacobs

    2008-01-25T23:59:59.000Z

    In this paper we discuss the impact of open source on both the security and transparency of a software system. We focus on the more technical aspects of this issue, combining and extending arguments developed over the years. We stress that our discussion of the problem only applies to software for general purpose computing systems. For embedded systems, where the software usually cannot easily be patched or upgraded, different considerations may apply.

  17. Far-infrared Point Sources

    E-Print Network [OSTI]

    B. Guiderdoni

    1999-03-08T23:59:59.000Z

    The analysis of the submm anisotropies that will be mapped by the forthcoming MAP and PLANCK satellites requires careful foreground subtraction before measuring CMB fluctuations. Among these, the foreground due to IR/submm thermal radiation from dusty sources was poorly known until recent observational breakthroughs began unveiling the properties of these objects. We hereafter briefly review the observational evidence for a strong evolution of IR/submm sources with respect to the local universe explored by IRAS. We present the basic principles of a new modeling effort where consistent spectral energy distributions of galaxies are implemented into the paradigm of hierarchical clustering with the fashionable semi-analytic approach. This model provides us with specific predictions in IR/submm wavebands, that seem to reproduce the current status of the observations and help assessing the capabilities of forthcoming instruments to pursue the exploration of the deep universe at IR/submm wavelengths. Finally, the ability of the PLANCK High Frequency Instrument all-sky survey to produce a catalogue of dusty sources at submm wavelengths is briefly described.

  18. Compact x-ray source and panel

    DOE Patents [OSTI]

    Sampayon, Stephen E. (Manteca, CA)

    2008-02-12T23:59:59.000Z

    A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

  19. Detecting fission from special nuclear material sources

    DOE Patents [OSTI]

    Rowland, Mark S. (Alamo, CA); Snyderman, Neal J. (Berkeley, CA)

    2012-06-05T23:59:59.000Z

    A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source. The system includes a graphing component that displays the plot of the neutron distribution from the unknown source over a Poisson distribution and a plot of neutrons due to background or environmental sources. The system further includes a known neutron source placed in proximity to the unknown source to actively interrogate the unknown source in order to accentuate differences in neutron emission from the unknown source from Poisson distributions and/or environmental sources.

  20. Multigamma-ray calibration sources

    SciTech Connect (OSTI)

    Meyer, R.A.; Massey, T.N.

    1983-05-01T23:59:59.000Z

    We have calibrated a self-consistent set of multigamma-ray standards using the automated multi-spectrometry ..gamma..-ray counting facility at LLNL's Nuclear Chemistry Division. Pure sources of long-lived activity were produced by mass separation and/or chemical purification. The sources were counted individually and in combination on several different calibrated spectrometer systems. These systems utilize various detectors ranging from small (x-ray) detectors to large volume high-purity Ge detectors. This has allowed the use of the most ideal individual detector-efficiency characteristics for the determination of the relative ..gamma..-ray intensities. Precise energy measurements, reported earlier (Meyer, 1976) have been performed by an independent method. Both the energy and ..gamma..-ray-emission probabilities determined compare well with independently established values such as the recent ICRM intercomparison of /sup 152/Eu. We discuss our investigations aimed at resolving the shape of the efficiency response function up to 10 MeV for large volume Ge(Li) and high-purity Ge detectors. Recent results on the ..gamma..-ray-emission probabilities per decay for /sup 149/Gd and /sup 168/Tm multigamma-ray sources are discussed. For /sup 168/Tm, we deduce a 0.01% ..beta../sup -/ branch to the 87.73-keV level in /sup 168/Yb rather than the previous value which was a factor of 200 greater. In addition, we describe current cooperative efforts aimed at establishing a consistent set of data for short-lived fission products. Included are recent measurements on the bromine fission products with ..gamma.. rays up to 7 MeV.

  1. Repatriation of US sources from Brazil

    SciTech Connect (OSTI)

    Tompkins, Andrew J [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    IAEA's interest in excess and unwanted sealed sources extends back to when radium sources were a problem throughout the world. Sta11ing in 1994, world wide IAEA member states inventoried and consolidated radium (Ra)-226 sources. IAEA then trained Regional Teams in the conditioning of Ra-226 sealed sources for long term storage, which resulted in the Regional Teams conditioning about 14,000 radium sources. These sources remained in their respective IAEA member state locations. Regional teams were seen as a way to encourage member state (local) management of a world wide problem, as well as a more cost effective solution.

  2. Thulium heat sources for space power applications

    SciTech Connect (OSTI)

    Alderman, C.J.

    1992-05-01T23:59:59.000Z

    Reliable power supplies for use in transportation and remote systems will be an important part of space exploration terrestrial activities. A potential power source is available in the rare earth metal, thulium. Fuel sources can be produced by activating Tm-169 targets in the space station reactor. The resulting Tm-170 heat sources can be used in thermoelectric generators to power instrumentation and telecommunications located at remote sites such as weather stations. As the heat source in a dynamic Sterling or Brayton cycle system, the heat source can provide a lightweight power source for rovers or other terrestrial transportation systems.

  3. Gamma source for active interrogation

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Lou, Tak Pui; Barletta, William A.

    2012-10-02T23:59:59.000Z

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  4. Charge exchange molecular ion source

    DOE Patents [OSTI]

    Vella, Michael C.

    2003-06-03T23:59:59.000Z

    Ions, particularly molecular ions with multiple dopant nucleons per ion, are produced by charge exchange. An ion source contains a minimum of two regions separated by a physical barrier and utilizes charge exchange to enhance production of a desired ion species. The essential elements are a plasma chamber for production of ions of a first species, a physical separator, and a charge transfer chamber where ions of the first species from the plasma chamber undergo charge exchange or transfer with the reactant atom or molecules to produce ions of a second species. Molecular ions may be produced which are useful for ion implantation.

  5. CHINA SPALLATION NEUTRON SOURCE DESIGN.

    SciTech Connect (OSTI)

    WEI,J.

    2007-01-29T23:59:59.000Z

    The China Spallation Neutron Source (CSNS) is an accelerator-based high-power project currently in preparation under the direction of the Chinese Academy of Sciences (CAS). The complex is based on an H- linear accelerator, a rapid cycling proton synchrotron accelerating the beam to 1.6 GeV, a solid tungsten target station, and five initial instruments for spallation neutron applications. The facility will operate at 25 Hz repetition rate with a phase-I beam power of about 120 kW. The major challenge is to build a robust and reliable user's facility with upgrade potential at a fractional of ''world standard'' cost.

  6. Relating to monitoring ion sources

    DOE Patents [OSTI]

    Orr, Christopher Henry (Calderbridge, GB); Luff, Craig Janson (Calderbridge, GB); Dockray, Thomas (Calderbridge, GB); Macarthur, Duncan Whittemore (Los Alamos, NM); Bounds, John Alan (Los Alamos, NM)

    2002-01-01T23:59:59.000Z

    The apparatus and method provide techniques for monitoring the position on alpha contamination in or on items or locations. The technique is particularly applicable to pipes, conduits and other locations to which access is difficult. The technique uses indirect monitoring of alpha emissions by detecting ions generated by the alpha emissions. The medium containing the ions is moved in a controlled manner frog in proximity with the item or location to the detecting unit and the signals achieved over time are used to generate alpha source position information.

  7. Gamma source for active interrogation

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA); Lou, Tak Pui (Berkeley, CA); Barletta, William A. (Oakland, CA)

    2009-09-29T23:59:59.000Z

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  8. Ion Sources - 88-Inch Cyclotron

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > The Energy Materials Center atdiffusivities in mesoporesSources The

  9. ARM - Sources of Atmospheric Carbon

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP :ProductsVaisalaAlaskaInstruments NSA Related LinksHomeroomSiteSources

  10. Manhattan Project: Sources and Notes

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy, science, and technology-- Energy,Science In the LaboratorySOURCES AND

  11. E Source | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualPropertyd8c-a9ae-f8521cbb8489 No revision| Open EnergyProjectDraper,NCNH)E ON Jump to:Source

  12. SourceRank: Relevance and Trust Assessment for Deep Web Sources Based on Inter-Source Agreement

    E-Print Network [OSTI]

    Kambhampati, Subbarao

    SourceRank: Relevance and Trust Assessment for Deep Web Sources Based on Inter-Source Agreement. Existing methods have two deficiencies for applying to the open col- lections like the deep web. First query in the deep web, the agreements between theses an- swer sets are likely to be helpful in assessing

  13. SourceRank: Relevance and Trust Assessment for Deep Web Sources Based on Inter-Source Agreement

    E-Print Network [OSTI]

    Kambhampati, Subbarao

    SourceRank: Relevance and Trust Assessment for Deep Web Sources Based on Inter-Source Agreement Tempe AZ USA 85287 rajub@asu.edu, rao@asu.edu ABSTRACT One immediate challenge in searching the deep web-similarity-based relevance assess- ment. When applied to the deep web these methods have two deficiencies. First

  14. Fluid jet electric discharge source

    DOE Patents [OSTI]

    Bender, Howard A. (Ripon, CA)

    2006-04-25T23:59:59.000Z

    A fluid jet or filament source and a pair of coaxial high voltage electrodes, in combination, comprise an electrical discharge system to produce radiation and, in particular, EUV radiation. The fluid jet source is composed of at least two serially connected reservoirs, a first reservoir into which a fluid, that can be either a liquid or a gas, can be fed at some pressure higher than atmospheric and a second reservoir maintained at a lower pressure than the first. The fluid is allowed to expand through an aperture into a high vacuum region between a pair of coaxial electrodes. This second expansion produces a narrow well-directed fluid jet whose size is dependent on the size and configuration of the apertures and the pressure used in the reservoir. At some time during the flow of the fluid filament, a high voltage pulse is applied to the electrodes to excite the fluid to form a plasma which provides the desired radiation; the wavelength of the radiation being determined by the composition of the fluid.

  15. Multi-source ion funnel

    DOE Patents [OSTI]

    Tang, Keqi; Belov, Mikhail B.; Tolmachev, Aleksey V.; Udseth, Harold R.; Smith, Richard D.

    2005-12-27T23:59:59.000Z

    A method for introducing ions generated in a region of relatively high pressure into a region of relatively low pressure by providing at least two electrospray ion sources, providing at least two capillary inlets configured to direct ions generated by the electrospray sources into and through each of the capillary inlets, providing at least two sets of primary elements having apertures, each set of elements having a receiving end and an emitting end, the primary sets of elements configured to receive a ions from the capillary inlets at the receiving ends, and providing a secondary set of elements having apertures having a receiving end and an emitting end, the secondary set of elements configured to receive said ions from the emitting end of the primary sets of elements and emit said ions from said emitting end of the secondary set of elements. The method may further include the step of providing at least one jet disturber positioned within at least one of the sets of primary elements, providing a voltage, such as a dc voltage, in the jet disturber, thereby adjusting the transmission of ions through at least one of the sets of primary elements.

  16. Air Permitting for Stationary Sources (New Hampshire)

    Broader source: Energy.gov [DOE]

    The permitting system implements the permitting requirements of RSA 125-C and 125-I to regulate the operation and modification of new and existing stationary sources, area sources, and devices to...

  17. Problems with packaged sources in foreign countries

    SciTech Connect (OSTI)

    Abeyta, Cristy L [Los Alamos National Laboratory; Matzke, James L [Los Alamos National Laboratory; Zarling, John [Los Alamos National Laboratory; Tompkin, J. Andrew [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    The Global Threat Reduction Initiative's (GTRI) Off-Site Source Recovery Project (OSRP), which is administered by the Los Alamos National Laboratory (LANL), removes excess, unwanted, abandoned, or orphan radioactive sealed sources that pose a potential threat to national security, public health, and safety. In total, GTRI/OSRP has been able to recover more than 25,000 excess and unwanted sealed sources from over 825 sites. In addition to transuranic sources, the GTRI/OSRP mission now includes recovery of beta/gamma emitting sources, which are of concern to both the U.S. government and the International Atomic Energy Agency (IAEA). This paper provides a synopsis of cooperative efforts in foreign countries to remove excess and unwanted sealed sources by discussing three topical areas: (1) The Regional Partnership with the International Atomic Energy Agency; (2) Challenges in repatriating sealed sources; and (3) Options for repatriating sealed sources.

  18. Science Highlights 2012 | Advanced Photon Source

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Argonne Advanced Photon Source and two other U.S. Department of Energy Office of Science synchrotron light sources. Their breakthrough results pave the way for development of...

  19. Science Highlights 2013 | Advanced Photon Source

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    from experiments carried out using x-rays from two U.S. Department of Energy Office of Science light sources including the Advanced Photon Source at Argonne National Laboratory...

  20. Dairy Biomass as a Renewable Fuel Source

    E-Print Network [OSTI]

    Mukhtar, Saqib; Goodrich, Barry; Engler, Cady; Capareda, Sergio

    2008-03-19T23:59:59.000Z

    biomass. This publication explains the properties of dairy manure that could make it an excellent source of fuel....

  1. North Village Ground Source Heat Pumps

    Broader source: Energy.gov [DOE]

    Overview: Installation of Ground Source Heat Pumps. Replacement of Aging Heat Pumps. Alignment with Furmans Sustainability Goals.

  2. Dairy Biomass as a Renewable Fuel Source 

    E-Print Network [OSTI]

    Mukhtar, Saqib; Goodrich, Barry; Engler, Cady; Capareda, Sergio

    2008-03-19T23:59:59.000Z

    biomass. This publication explains the properties of dairy manure that could make it an excellent source of fuel....

  3. Source integrals of asymptotic multipole moments

    E-Print Network [OSTI]

    Norman Gürlebeck

    2013-02-28T23:59:59.000Z

    We derive source integrals for multipole moments that describe the behaviour of static and axially symmetric spacetimes close to spatial infinity. We assume isolated non-singular sources but will not restrict the matter content otherwise. Some future applications of these source integrals of the asymptotic multipole moments are outlined as well.

  4. Nonlinear structures of the Korteweg-de Vries and modified Korteweg-de Vries equations in non-Maxwellian electron-positron-ion plasma: Solitons collision and rogue waves

    SciTech Connect (OSTI)

    El-Tantawy, S. A., E-mail: samireltantawy@yahoo.com [Department of Physics, Faculty of Science, Port Said University, Port Said 42521 (Egypt); Moslem, W. M., E-mail: wmmoslem@hotmail.com [Department of Physics, Faculty of Science, Port Said University, Port Said 42521 (Egypt); Centre for Theoretical Physics, The British University in Egypt (BUE), El-Shorouk City, Cairo (Egypt)

    2014-05-15T23:59:59.000Z

    Solitons (small-amplitude long-lived waves) collision and rogue waves (large-amplitude short-lived waves) in non-Maxwellian electron-positron-ion plasma have been investigated. For the solitons collision, the extended Poincaré-Lighthill-Kuo perturbation method is used to derive the coupled Korteweg-de Vries (KdV) equations with the quadratic nonlinearities and their corresponding phase shifts. The calculations reveal that both positive and negative polarity solitons can propagate in the present model. At critical value of plasma parameters, the coefficients of the quadratic nonlinearities disappear. Therefore, the coupled modified KdV (mKdV) equations with cubic nonlinearities and their corresponding phase shifts have been derived. The effects of the electron-to-positron temperature ratio, the ion-to-electron temperature ratio, the positron-to-ion concentration, and the nonextensive parameter on the colliding solitons profiles and their corresponding phase shifts are examined. Moreover, generation of ion-acoustic rogue waves from small-amplitude initial perturbations in plasmas is studied in the framework of the mKdV equation. The properties of the ion-acoustic rogue waves are examined within a nonlinear Schrödinger equation (NLSE) that has been derived from the mKdV equation. The dependence of the rogue wave profile on the relevant physical parameters has been investigated. Furthermore, it is found that the NLSE that has been derived from the KdV equation cannot support the propagation of rogue waves.

  5. Solenoid and monocusp ion source

    DOE Patents [OSTI]

    Brainard, J.P.; Burns, E.J.T.; Draper, C.H.

    1997-10-07T23:59:59.000Z

    An ion source which generates hydrogen ions having high atomic purity incorporates a solenoidal permanent magnets to increase the electron path length. In a sealed envelope, electrons emitted from a cathode traverse the magnetic field lines of a solenoid and a monocusp magnet between the cathode and a reflector at the monocusp. As electrons collide with gas, the molecular gas forms a plasma. An anode grazes the outer boundary of the plasma. Molecular ions and high energy electrons remain substantially on the cathode side of the cusp, but as the ions and electrons are scattered to the aperture side of the cusp, additional collisions create atomic ions. The increased electron path length allows for smaller diameters and lower operating pressures. 6 figs.

  6. Top Quark Physics at the ILC: Methods and Meanings

    E-Print Network [OSTI]

    Zack Sullivan

    2009-03-06T23:59:59.000Z

    The physics case for studying top-quark physics at the International Linear Collider is well established. This summary places in context the top-quark physics goals, examines the current state-of-the art in understanding of the top-quark mass, and identifies some areas in which the study of the top-quark mass enhances our understanding of new techniques.

  7. Research on Field Emission and Dark Current in ILC Cavities

    SciTech Connect (OSTI)

    Liu, Kexin; Li, Yongming; Palczewski, Ari; Geng, Rongli

    2013-09-01T23:59:59.000Z

    Field emission and dark current are issues of concern for SRF cavity performance and SRF linac operation. Complete understanding and reliable control of the issue are still needed, especially in full-scale multi-cell cavities. Our work aims at developing a generic procedure for finding an active field emitter in a multi-cell cavity and benchmarking the procedure through cavity vertical test. Our ultimate goal is to provide feedback to cavity preparation and cavity string assembly in order to reduce or eliminate filed emission in SRF cavities. Systematic analysis of behaviors of field emitted electrons is obtained by ACE3P developed by SLAC. Experimental benchmark of the procedure was carried out in a 9-cell cavity vertical test at JLab. The energy spectrum of Bremsstrahlung X-rays is measured using a NaI(Tl) detector. The end-point energy in the X-ray energy spectrum is taken as the highest kinetic electron energy to predict longitudinal position of the active field emitter. Angular location of the field emitter is determined by an array of silicon diodes around irises of the cavity. High-resolution optical inspection was conducted at the predicted field emitter location.

  8. Fast Ferroelectric L-Band Tuner for ILC Cavities

    SciTech Connect (OSTI)

    Hirshfield, Jay L

    2010-03-15T23:59:59.000Z

    Design, analysis, and low-power tests are described on a 1.3 GHz ferroelectric tuner that could find application in the International Linear Collider or in Project X at Fermi National Accelerator Laboratory. The tuner configuration utilizes a three-deck sandwich imbedded in a WR-650 waveguide, in which ferroelectric bars are clamped between conducting plates that allow the tuning bias voltage to be applied. Use of a reduced one-third structure allowed tests of critical parameters of the configuration, including phase shift, loss, and switching speed. Issues that were revealed that require improvement include reducing loss tangent in the ferroelectric material, development of a reliable means of brazing ferroelectric elements to copper parts of the tuner, and simplification of the mechanical design of the configuration.

  9. Comparison of LHC and ILC Capabilities for Higgs Boson Coupling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power Administration would like submit the followingthMeasurements | SciTech Connect Journal

  10. ILC Treatment of JLab Cavity Garners Exciting Result | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh School footballHydrogen andHypernuclei in Hall link

  11. ILC Treatment of JLab Cavity Garners Exciting Result | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh School footballHydrogen andHypernuclei in Hall linkTreatment of JLab

  12. About Fermilab | Fermilab and the Community | ILC Citizens' Task Force

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProducts (VAP) VAP7-0973 1 Introduction In the design This page

  13. Ion source based on the cathodic arc

    DOE Patents [OSTI]

    Sanders, D.M.; Falabella, S.

    1994-02-01T23:59:59.000Z

    A cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated, is described. An array of electrically isolated rings positioned in the source serves the dual purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles. 3 figures.

  14. Source depth for solar p-modes

    E-Print Network [OSTI]

    Pawan Kumar; Sarbani Basu

    2000-06-15T23:59:59.000Z

    Theoretically calculated power spectra are compares with observed solar p-mode velocity power spectra over a range of mode degree and frequency. The depth for the sources responsible for exciting p-modes of frequency 2.0 mHz is determined from the asymmetry of their power spectra and found to be about 800 km below the photosphere for quadrupole sources and 150 km if sources are dipole. The source depth for high frequency oscillations of frequency greater than about 6 mHz is 180 (50) km for quadrupole (dipole) sources.

  15. Effect of nonthermal electrons on the propagation characteristics and stability of two-dimensional nonlinear electrostatic coherent structures in relativistic electron positron ion plasmas

    SciTech Connect (OSTI)

    Masood, W. [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); National Centre for Physics (NCP), Shahdara Valley Road, 44000 Islamabad (Pakistan); Rizvi, H. [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan)

    2011-06-15T23:59:59.000Z

    Two-dimensional propagation of nonlinear ion acoustic shock and solitary waves in an unmagnetized plasma consisting of nonthermal electrons, Boltzmannian positrons, and singly charged hot ions streaming with relativistic velocities are investigated. The system of fluid equations is reduced to Kadomtsev-Petviashvili-Burgers and Kadomtsev-Petviashvili (KP) equations in the limit of small amplitude perturbation. The dependence of the ion acoustic shock and solitary waves on various plasma parameters are explored in detail. Interestingly, it is observed that increasing the nonthermal electron population increases the wave dispersion which enervates the strength of the ion acoustic shock wave; however, the same effect leads to an enhancement of the soliton amplitude due to the absence of dissipation in the KP equation. The present investigation may be useful to understand the two-dimensional propagation characteristics of small but finite amplitude localized shock and solitary structures in planetary magnetospheres and auroral plasmas where nonthermal populations of electrons have been observed by several satellite missions.

  16. International workshop on cold neutron sources

    SciTech Connect (OSTI)

    Russell, G.J.; West, C.D. (comps.) (Los Alamos National Lab., NM (United States)) [comps.; Los Alamos National Lab., NM (United States)

    1991-08-01T23:59:59.000Z

    The first meeting devoted to cold neutron sources was held at the Los Alamos National Laboratory on March 5--8, 1990. Cosponsored by Los Alamos and Oak Ridge National Laboratories, the meeting was organized as an International Workshop on Cold Neutron Sources and brought together experts in the field of cold-neutron-source design for reactors and spallation sources. Eighty-four people from seven countries attended. Because the meeting was the first of its kind in over forty years, much time was spent acquainting participants with past and planned activities at reactor and spallation facilities worldwide. As a result, the meeting had more of a conference flavor than one of a workshop. The general topics covered at the workshop included: Criteria for cold source design; neutronic predictions and performance; energy deposition and removal; engineering design, fabrication, and operation; material properties; radiation damage; instrumentation; safety; existing cold sources; and future cold sources.

  17. Blind source separation in the presence of weak sources J.-P. Nadala

    E-Print Network [OSTI]

    Aires, Filipe

    Blind source separation in the presence of weak sources J.-P. Nadala , E. Korutchevab,*, F. Airesa" as compared to the other ones, the "weak" sources. We find that it is preferable to perform blind source simulations. 2000 Elsevier Science Ltd. All rights reserved. Keywords: Independent component analysis; Blind

  18. Blind Source Separation 2 Understanding Two Simultaneous Speeches by Blind Source Separation

    E-Print Network [OSTI]

    Ikeda, Shiro

    Blind Source Separation 2 Understanding Two Simultaneous Speeches by Blind Source Separation) to segregate speech streams from a mixture of sounds, while the other ex- ploits Blind Source Separation the performance of Blind Source Separation by using the same three benchmarks of 500 mix- ture of two speeches

  19. Source-to-Source Architecture Transformation for Performance Optimization in BIP

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Source-to-Source Architecture Transformation for Performance Optimization in BIP Marius Bozga of composition operators: inter- actions and priorities. In this paper we present a method that transforms of the interconnection of components [14]. Source-to-source transformations have been considered as a powerful means

  20. The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part 1: Overview

    E-Print Network [OSTI]

    Billing, M G

    2015-01-01T23:59:59.000Z

    Cornell's electron/positron storage ring (CESR) was modified over a series of accelerator shutdowns beginning in May 2008, which substantially improves its capability for research and development for particle accelerators. CESR's energy span from 1.8 to 5.6 GeV with both electrons and positrons makes it ideal for the study of a wide spectrum of accelerator physics issues and instrumentation related to present light sources and future lepton damping rings. Additionally a number of these are also relevant for the beam physics of proton accelerators. This paper outlines the motivation, design and conversion of CESR to a test accelerator, CesrTA, enhanced to study such subjects as low emittance tuning methods, electron cloud (EC) effects, intra-beam scattering, fast ion instabilities as well as general improvements to beam instrumentation. While the initial studies of CesrTA focussed on questions related to the International Linear Collider (ILC) damping ring design, CesrTA is a very flexible storage ring, capabl...