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1

ILC Positron source simualtion  

NLE Websites -- All DOE Office Websites (Extended Search)

(DOE Review 2007) (DOE Review 2007) Wanming Liu, Haitao Wang, Sergey Antipov, Wei Gai, Kwang-Je Kim HEP, ANL 04/27/2007 Where we are making contribution * Undulator radiation modeling * Adiabatic Matching Device modeling * Keep alive source simulation * Thermal dynamic study on windows * Eddy current simulation * Laser compton scheme positron production simulation for KEK/CLIC Where we are making contributions Outline Undulator and e+ yield OMD/AMD modeling and designing Thermal dynamic of target chamber window Energy deposition profile of target Collaboration with KEK/CLIC Comparison of positron yield from different undulators High K Devices Low K Devices BCD UK I UK II UK III Cornell I Cornell II Cornell III Period (mm) 10.0 11.5 11.0 10.5 10.0 12.0 7 0.3 0.46 28 ~0.54 Yield(Low Pol, 500m drift) ~2.13

2

Heat Deposition in Positron Sources for ILC  

Science Conference Proceedings (OSTI)

In the International Linear Collider (ILC) positron source, multi-GeV electrons or multi-MeV photons impinge on a metal target to produce the needed positrons in the resulting electromagnetic showers. The incoming beam power is hundreds of kilowatts. Various computer programs -- such as FLUKA or MARS -- can calculate how the incoming beam showers in the target and can track the particle showers through the positron source system. Most of the incoming energy ends up as heat in the various positron source elements. This paper presents results from such calculations and their impact on the design of a positron source for the ILC.

Bharadwaj, V.; Pitthan, R.; Sheppard, J.; Vincke, H.; Wang, J.W.; /SLAC

2006-03-15T23:59:59.000Z

3

Update on ILC Positron Source Study at ANL  

NLE Websites -- All DOE Office Websites (Extended Search)

USA Abstract As the new ILC baseline has moved the positron production to the end of electron main linac, both the drive beam energy and beamline layouts have also been changed...

4

On the Polarization Upgrade of ILC Undulator-based Positron Source  

NLE Websites -- All DOE Office Websites (Extended Search)

paper. INTRODUCTION The ILC SB2009 base line positron source is located at the end of electron main linac and it is still using the RDR undulator with K0.92 and u1.15cm1....

5

Studies of Room Temperature Accelerator Structures for the ILC Positron Source  

SciTech Connect

There are many challenges in the design of the normal-conducting portion of the ILC positron injector system such as achieving adequate cooling with the high RF and particle loss heating, and sustaining high accelerator gradients during millisecond-long pulses in a strong magnetic field. The proposed design for the positron injector contains both standing-wave and traveling-wave L-band accelerator structures for high RF efficiency, low cost and ease of fabrication. This paper presents results from several studies including particle energy deposition for both undulator based and conventional positron sources, cooling system design, accelerator structure optimization, RF pulse heating, cavity frequency stabilization, and RF feed system design.

Wang, J.W.; Adolphsen, C.; Bharadwaj, V.; Bowden, G.B.; Dolgashev, V.A.; Jones, R.M.; Jongewaard, E.N.; Lewandowski, J.R.; Li, Z.; Miller, R.H.; /SLAC

2006-03-15T23:59:59.000Z

6

Update on the ILC Positron Source Study at ANL  

NLE Websites -- All DOE Office Websites (Extended Search)

GeV THPEC036 Proceedings of IPAC'10, Kyoto, Japan 4134 03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques T02 Lepton Sources beam will lose less energy...

7

Prototyping of the ILC Baseline Positron Target  

SciTech Connect

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.

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

2012-02-29T23:59:59.000Z

8

ILC Positron source simualtion  

NLE Websites -- All DOE Office Websites (Extended Search)

capture studies: how well does this work? Essentially want zero field on target Energy deposition calculations for RAL material optimization: start with 5-D acceptance...

9

Polarized positrons for the ILC - update on simulations  

E-Print Network (OSTI)

To achieve the extremely high luminosity for colliding electron-positron beams at the future International Linear Collider (ILC) an undulator-based source with about 230 meters helical undulator and a thin titanium-alloy target rim rotated with tangential velocity of about 100 meters per second are foreseen. The very high density of heat deposited in the target has to be analyzed carefully. The energy deposited by the photon beam in the target has been calculated in FLUKA. The resulting stress in the target material after one bunch train has been simulated in ANSYS.

Staufenbiel, F

2012-01-01T23:59:59.000Z

10

ILC Electron Source Injector Simuations  

SciTech Connect

As part of the global project aimed at proposing an efficient design for the ILC (International Linear Collider), we simulated possible setups for the electron source injector, which will provide insight into how the electron injector for the ILC should be designed in order to efficiently accelerate the electron beams through the bunching system. This study uses three types of software: E-Gun to simulate electron beam emission, Superfish to calculate solenoidal magnetic fields, and GPT (General Particle Tracer) to trace charged particles after emission through magnetic fields and subharmonic bunchers. We performed simulations of the electron source injector using various electron gun bias voltages (140kV - 200kV), emitted beam lengths (500ps - 1ns) and radii (7mm - 10mm), and electromagnetic field strengths of the first subharmonic buncher (5 - 20 MV/m). The results of the simulations show that for the current setup of the ILC, a modest electron gun bias voltage ({approx}140kV) is sufficient to achieve the required bunching of the beam in the injector. Extensive simulations of parameters also involving the second subharmonic buncher should be performed in order to gain more insight into possible efficient designs for the ILC electron source injector.

Lakshmanan, Manu; /Cornell U., LNS /SLAC

2007-08-29T23:59:59.000Z

11

ILC Polarized Electron Source Design and R&D Program  

Science Conference Proceedings (OSTI)

The R and D program for the ILC electron focuses on three areas. These are the source drive laser system, the electron gun and photo cathodes necessary to produce a highly polarized electron beam. Currently, the laser system and photo cathode development take place at SLAC's 'ILC Injector Test facility', which is an integrated lab (laser and gun) that allows the production of the electron beam and is equipped with a set of diagnostics, necessary to characterize the source performance. Development of the ILC electron gun takes place at Jefferson Lab, where advanced concepts and technologies for HV DC electron guns for polarized beams are being developed. The goal is to combine both efforts at one facility to demonstrate an electron beam with ILC specifications, which are electron beam charge and polarization as well as the cathode's lifetime. The source parameters are summarized in Table 1. The current schematic design of the ILC central complex is depicted in Figure 1. The electron and positron sources are located and laid out approximately symmetric on either side of the damping rings.

Brachmann, A.; Sheppard, J.; Zhou, F.; Poelker, M.; /SLAC

2012-04-06T23:59:59.000Z

12

ILC cryogenic systems reference design  

SciTech Connect

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.

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

2008-01-01T23:59:59.000Z

13

Design of An 18 MW Beam Dump for 500 GeV Electron/Positron Beams at An ILC  

SciTech Connect

This article presents a report on the progress made in designing 18 MW water based Beam Dumps for electrons or positrons for an International Linear Collider (ILC). Multi-dimensional technology issues have to be addressed for the successful design of the Beam Dump. They include calculations of power deposition by the high energy electron/positron beam bunch trains, computational fluid dynamic analysis of turbulent water flow, mechanical design, process flow analysis, hydrogen/oxygen recombiners, handling of radioactive 7Be and 3H, design of auxiliary equipment, provisions for accident scenarios, remote window exchanger, radiation shielding, etc. The progress made to date is summarized, the current status, and also the issues still to be addressed.

Amann, John; /SLAC; Arnold, Ray; /SLAC; Seryi, Andrei; /SLAC; Walz, Dieter; /SLAC; Kulkarni, Kiran; /Bhabha Atomic Res. Ctr.; Rai, Pravin; /Bhabha Atomic Res. Ctr.; Satyamurthy, Polepalle; /Bhabha Atomic Res. Ctr.; Tiwari, Vikar; /Bhabha Atomic Res. Ctr.; Vincke, Heinz; /CERN

2012-07-05T23:59:59.000Z

14

Design of an 18 MW Beam Dump for 500 GeV Electron/Positron Beams at an ILC  

E-Print Network (OSTI)

This article presents a report on the progress made in designing 18 MW water based Beam Dumps for electrons or positrons for an International Linear Collider (ILC). Multi-dimensional technology issues have to be addressed for the successful design of the Beam Dump. They include calculations of power deposition by the high energy electron/positron beam bunch trains, computational fluid dynamic analysis of turbulent water flow, mechanical design, process flow analysis, hydrogen/oxygen recombiners, handling of radioactive 7Be and 3H, design of auxiliary equipment, provisions for accident scenarios, remote window exchanger, radiation shielding, etc. The progress made to date is summarized, the current status, and also the issues still to be addressed

Amann, John; Seryi, Andrei; Walz, Dieter; Kulkarni, Kiran; Rai, Pravin; Satyamurthy, Polepalle; Tiwari, Vikar; Vincke, Heinz

2010-01-01T23:59:59.000Z

15

Positron source position sensing detector and electronics  

DOE Patents (OSTI)

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.

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

16

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

SciTech Connect

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.

Serkan Golge

2010-08-31T23:59:59.000Z

17

An Undulator Based Polarized Positron Source for CLIC  

Science Conference Proceedings (OSTI)

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.

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

2012-07-02T23:59:59.000Z

18

Cosmic-Ray Positrons: Are There Primary Sources?  

E-Print Network (OSTI)

Cosmic rays at the Earth include a secondary component originating in collisions of primary particles with the diffuse interstellar gas. The secondary cosmic rays are relatively rare but carry important information on the Galactic propagation of the primary particles. The secondary component includes a small fraction of antimatter particles, positrons and antiprotons. In addition, positrons and antiprotons may also come from unusual sources and possibly provide insight into new physics. For instance, the annihilation of heavy supersymmetric dark matter particles within the Galactic halo could lead to positrons or antiprotons with distinctive energy signatures. With the High-Energy Antimatter Telescope (HEAT) balloon-borne instrument, we have measured the abundances of positrons and electrons at energies between 1 and 50 GeV. The data suggest that indeed a small additional antimatter component may be present that cannot be explained by a purely secondary production mechanism. Here we describe the signature of the effect and discuss its possible origin.

Stephane Coutu; Steven W. Barwick; James J. Beatty; Amit Bhattacharyya; Chuck R. Bower; Christopher J. Chaput; Georgia A. de Nolfo; Michael A. DuVernois; Allan Labrador; Shawn P. McKee; Dietrich Muller; James A. Musser; Scott L. Nutter; Eric Schneider; Simon P. Swordy; Gregory Tarle; Andrew D. Tomasch; Eric Torbet

1999-02-10T23:59:59.000Z

19

Status of the ILC Crab Cavity Development  

SciTech Connect

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.

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

20

Executive Summary of the Workshop on Polarization and Beam Energy Measurements at the ILC  

SciTech Connect

This note summarizes the results of the 'Workshop on Polarization and Beam Energy Measurements at the ILC', held at DESY (Zeuthen) April 9-11 2008. The topics for the workshop included (1) physics requirements, (2) polarized sources and low energy polarimetry, (3) BDS polarimeters, (4) BDS energy spectrometers, and (5) physics-based measurements of beam polarization and beam energy from collider data. Discussions focused on the current ILC baseline program as described in the Reference Design Report (RDR), which includes physics runs at beam energies between 100 and 250 GeV, as well as calibration runs on the Z-pole. Electron polarization of P{sub e{sup -}} {approx}> 80% and positron polarization of P{sub e{sup +}} {approx}> 30% are part of the baseline configuration of the machine. Energy and polarization measurements for ILC options beyond the baseline, including Z-pole running and the 1 TeV energy upgrade, were also discussed.

Aurand, B.; Bailey, I.; Bartels, C.; Blair, G.; Brachmann, A.; Clarke, J.; Deacon, L.; Duginov, V.; Ghalumyan, A.; Hartin, A.; Hauptman, J.; Helebrant, C.; Hesselbach, S.; Kafer, D.; List, J.; Lorenzon, W.; Lyapin, A.; Marchesini, I.; Melikian, R.; Monig, K.; Moeit, K.C.; /Bonn U. /Cockcroft Inst. Accel. Sci. Tech. /DESY /DESY, Zeuthen /Royal Holloway, U. of London /SLAC /Daresbury /Dubna, JINR /Yerevan Phys. Inst /Oxford U., JAI /Iowa State U. /Durham U., IPPP /Michigan U. /University Coll. London /Novosibirsk, IYF /Minsk, Inst. Phys. /Oregon U.

2008-07-25T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Conceptual design of a high-intensity positron source for the Advanced Neutron Source  

SciTech Connect

The Advanced Neutron Source (ANS) is a planned new basic and applied research facility based on a powerful steady-state research reactor that provides neutrons for measurements and experiments in the fields of materials science and engineering, biology, chemistry, materials analysis, and nuclear science. The useful neutron flux will be at least five times more than is available in the world`s best existing reactor facility. Construction of the ANS provides a unique opportunity to build a positron spectroscopy facility (PSF) with very-high-intensity beams based on the radioactive decay of a positron-generating isotope. The estimated maximum beam current is 1000 to 5000 times higher than that available at the world`s best existing positron research facility. Such an improvement in beam capability, coupled with complementary detectors, will reduce experiment durations from months to less than one hour while simultaneously improving output resolution. This facility will remove the existing barriers to the routine use of positron-based analytical techniques and will be a giant step toward realization of the full potential of the application of positron spectroscopy to materials science. The ANS PSF is based on a batch cycle process using {sup 64}Cu isotope as the positron emitter and represents the status of the design at the end of last year. Recent work not included in this report, has led to a proposal for placing the laboratory space for the positron experiments outside the ANS containment; however, the design of the positron source is not changed by that relocation. Hydraulic and pneumatic flight tubes transport the source material between the reactor and the positron source where the beam is generated and conditioned. The beam is then transported through a beam pipe to one of several available detectors. The design presented here includes all systems necessary to support the positron source, but the beam pipe and detectors have not been addressed yet.

Hulett, L.D.; Eberle, C.C.

1994-12-01T23:59:59.000Z

22

Engineering basis for selection of positron source material  

Science Conference Proceedings (OSTI)

This note describes the engineering basis for the selection of the positron source material. It assumes the approximate physics parameters have already been chosen (i.e. a high Z material of 6 radiation lengths thickness). As part of this study a basic heat transfer analysis of the target was performed and is discussed. It is concluded that Ta-10W is the most likely material to meet required physics parameters and not fail structurally.

Feerick, B.

1983-10-10T23:59:59.000Z

23

HIGH INTENSITY LOW-ENERGY POSITRON SOURCE AT JEFFERSON  

SciTech Connect

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.

Serkan Golge, Bogdan Wojtsekhowski, Branislav Vlahovic

2012-07-01T23:59:59.000Z

24

Delayed ILC Roadmap  

NLE Websites -- All DOE Office Websites (Extended Search)

ILCTA plans and opportunities ILCTA plans and opportunities ILCTA plans and opportunities November 27, 2007 Sergei Nagaitsev FNAL S. Nagaitsev 2 ILC ILC Cryomodule Cryomodule Cryomodules are complex 8 or 9 Cavities, ultra clean surfaces Operate in 2K superfluid He Quad Focusing magnets Couplers feed RF energy to cavities Tuners adjust cavity resonant frequency to match klystron 1200 parts ! Cryomodules are expensive Single most expensive component of the ILC About 2000 are needed for the ILC, 40 for Project X FNAL leads an international team working to improve the TESLA CM design for ILC (DESY, INFN, KEK, CERN, SLAC, India, etc ILC must industrialize cavities, components, & maybe assembly Developing the extensive infrastructure to build and test CM's

25

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

Science Conference Proceedings (OSTI)

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.

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

26

ILC Higgs White Paper  

E-Print Network (OSTI)

The ILC Higgs White Paper is a review of Higgs Boson theory and experiment at the International Linear Collider (ILC). Theory topics include the Standard Model Higgs, the two-Higgs doublet model, alternative approaches to electroweak symmetry breaking, and precision goals for Higgs boson experiments. Experimental topics include the measurement of the Higgs cross section times branching ratio for various Higgs decay modes at ILC center of mass energies of 250, 500, and 1000 GeV, and the extraction of Higgs couplings and the total Higgs width from these measurements. Luminosity scenarios based on the ILC TDR machine design are used throughout. The gamma-gamma collider option at the ILC is also discussed.

D. M. Asner; T. Barklow; C. Calancha; K. Fujii; N. Graf; H. E. Haber; A. Ishikawa; S. Kanemura; S. Kawada; M. Kurata; A. Miyamoto; H. Neal; H. Ono; C. Potter; J. Strube; T. Suehara; T. Tanabe; J. Tian; K. Tsumura; S. Watanuki; G. Weiglein; K. Yagyu; H. Yokoya

2013-10-02T23:59:59.000Z

27

PSU-PAL-99-1 Cosmic-Ray Positrons: Are There Primary Sources?  

E-Print Network (OSTI)

Galactic cosmic rays consist of primary and secondary particles. Primary cosmic rays are thought to be energized by first order Fermi acceleration processes at supernova shock fronts within our Galaxy. The cosmic rays that eventually reach the Earth from this source are mainly protons and atomic nuclei, but also include electrons. Secondary cosmic rays are created in collisions of primary particles with the diffuse interstellar gas. They are relatively rare but carry important information on the Galactic propagation of the primary particles. The secondary component includes a small fraction of antimatter particles, positrons and antiprotons. In addition, positrons and antiprotons may also come from unusual sources and possibly provide insight into new physics. For instance, the annihilation of heavy supersymmetric dark matter particles within the Galactic halo could lead to positrons or antiprotons with distinctive energy signatures. With the High-Energy

Stéphane Coutu; Steven W. Barwick; James J. Beatty; Amit Bhattacharyya; R. Bower; Christopher J. Chaput; Georgia A. De Nolfo; Michael A. Duvernois; Shawn P. Mckee; Dietrich Müller; James A. Musser; Scott L. Nutter; Simon P. Swordy; Gregory Tarlé; Andrew D. Tomasch; Eric Torbet

1999-01-01T23:59:59.000Z

28

ILC Citizens' Task Force  

NLE Websites -- All DOE Office Websites (Extended Search)

the Fermilab ILC Citizens' Task Force June 2008 Report of the Fermilab ILC Citizens' Task Force 3 Contents 1 Executive Summary 3 Chapter 1 Purpose 7 Chapter 2 Origins and Purpose of the Fermilab Citizens' Task Force 15 Chapter 3 Setting the Stage 19 Chapter 4 Current Status of High Energy Physics Research 25 Chapter 5 Bringing the Next-Generation Accelerator to Fermilab 31 Chapter 6 Learning from Past Projects 37 Chapter 7 Location, Construction and Operation of Facilities Beyond Fermilab's Borders 45 Chapter 8 Health and Safety 49 Chapter 9 Environment 53 Chapter 10 Economics 59 Chapter 11 Political Considerations 65 Chapter 12 Community Engagement 77 Chapter 13 Summary 81 Appendices Appendix A. Task Force Members Appendix B. Task Force Meetings and Topics

29

Wake potentials of the ILC Interaction Region  

SciTech Connect

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.

Novokhatski, A.; /SLAC

2011-08-16T23:59:59.000Z

30

Physics Benchmarks for the ILC Detectors  

E-Print Network (OSTI)

This note presents a list of physics processes for benchmarking the performance of proposed ILC detectors. This list gives broad coverage of the required physics capabilities of the ILC experiments and suggests target accuracies to be achieved. A reduced list of reactions, which capture within a very economical set the main challenges put by the ILC physics program, is suggested for the early stage of benchmarking of the detector concepts.

M. Battaglia; T. Barklow; M. Peskin; Y. Okada; S. Yamashita; P. Zerwas

2006-03-06T23:59:59.000Z

31

Round Robin (Interlaboratory Comparison, ILC) Tools  

Science Conference Proceedings (OSTI)

... (Ref. NISTIR 7214, sections 1.0 & 1.6.) OWM Policy & Quality System. ... Form 3: PT/ILC Training & Qualifications Revision Date: March 2005 DOC; ...

2013-07-15T23:59:59.000Z

32

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

E-Print Network (OSTI)

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.

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

33

Design of the ILC Crab Cavity System  

SciTech Connect

The International Linear Collider (ILC) has a 14 mrad crossing angle in order to aid extraction of spent bunches. As a result of the bunch shape at the interaction point, this crossing angle at the collision causes a large luminosity loss which can be recovered by rotating the bunches prior to collision using a crab cavity. The ILC baseline crab cavity is a 9-cell superconducting dipole cavity operating at a frequency of 3.9 GHz. In this paper the design of the ILC crab cavity and its phase control system, as selected for the RDR in February 2007 is described in fuller detail.

Adolphsen, C.; Beard, C.; Bellantoni, L.; Burt, G.; Carter, R.; Chase, B.; Church, M.; Dexter, A.; Dykes, M.; Edwards, H.; Goudket, P; Jenkins, R.; Jones, R.M.; Kalinin, A.; Khabiboulline, T.; Ko, K.; Latina, A.; Li, Z.; Ma, L.; McIntosh, P.; Ng, C.; /SLAC /Daresbury /Fermilab /Cockcroft Inst. Accel. Sci. Tech. /CERN

2007-08-15T23:59:59.000Z

34

Availability and Reliability Issues for ILC  

SciTech Connect

The International Linear Collider (ILC) will be the largest most complicated accelerator ever built. For this reason extensive work is being done early in the design phase to ensure that it will be reliable enough. This includes gathering failure mode data from existing accelerators and simulating the failures and repair times of the ILC. This simulation has been written in a general fashion using MATLAB and could be used for other accelerators. Results from the simulation tool have been used in making some of the major ILC design decisions and an unavailability budget has been developed.

Himel, T.; Nelson, J.; Phinney, N.; /SLAC; Ross, M.; /Fermilab

2007-06-27T23:59:59.000Z

35

Muon ID at the ILC  

SciTech Connect

This paper describes a new way to reconstruct and identify muons with high efficiency and high pion rejection. Since muons at the ILC are often produced with or in jets, for many of the physics channels of interest [1], an efficient algorithm to deal with the identification and separation of particles within jets is important. The algorithm at the core of the method accounts for the effects of the magnetic field and for the loss of energy by charged particles due to ionization in the detector. We have chosen to develop the analysis within the setup of one of the Linear Collider Concept Detectors adopted by the US. Within b-pair production jets, particles cover a wide range in momenta; however {approx}80% of the particles have a momentum below 30 GeV[2]. Our study, focused on bbar-b jets, is preceded by a careful analysis of single energy particles between 2 and 50 GeV. As medium energy particles are a substantial component of the jets, many of the particles lose part of their energy in the calorimeters and the solenoid coil before reaching the muon detector where they may have energy below 2 GeV. To deal with this problem we have implemented a Runge-Kutta correction of the calculated trajectory to better handle these lower energy particles. The multiple scattering and other stochastic processes, more important at lower energy, is addressed by a Kalman-filter integrated into the reconstruction algorithm. The algorithm provides a unique and powerful separation of muons from pions. The 5 Tesla magnetic field from a solenoid surrounds the hadron calorimeter and allows the reconstruction and precision.

Milstene, C.; Fisk, G.; Para, A.; /Fermilab

2006-09-01T23:59:59.000Z

36

About Fermilab | Fermilab and the Community | ILC Citizens' Task Force |  

NLE Websites -- All DOE Office Websites (Extended Search)

Meeting Materials Meeting Materials January 27, 2007 Retreat and Tour Agenda (pdf) Presentation by Judy Jackson, Fermilab Director of Communication (pdf) Photos Video March 1, 2007 Introduction to Particle Physics Agenda (pdf) Presentation by Pier Oddone, Fermilab Director (ppt - 13.5M) Presentation by Fermilab Physicist Chris Quigg (pdf - 12M) Photos March 27, 2007 Introduction to the ILC Agenda (pdf) Fermilab Area map with outlines (jpg) ILC by the Numbers (pdf) How does the ILC work? (pdf) ILC Reference Design Companion Document (pdf) Results of Task Force Dialogue on Community Values(pdf) May 1, 2007 The ILC Global Design Effort Agenda (pdf) Presentation by GDE Director Barry Barish (pdf) Photos Video: Part 1 | Part 2 May 22, 2007 Locating the ILC at Fermilab Agenda (pdf) Maps of potential locations for the ILC:

37

Positron microscopy  

Science Conference Proceedings (OSTI)

The negative work function property that some materials have for positrons make possible the development of positron reemission microscopy (PRM). Because of the low energies with which the positrons are emitted, some unique applications, such as the imaging of defects, can be made. The history of the concept of PRM, and its present state of development will be reviewed. The potential of positron microprobe techniques will be discussed also.

Hulett, L.D. Jr.; Xu, J.

1995-02-01T23:59:59.000Z

38

Proposed ILC Parameters T.O. Raubenheimer  

NLE Websites -- All DOE Office Websites (Extended Search)

-05-98 -05-98 Proposed ILC Parameters T.O. Raubenheimer and K. Yokoya Introduction In this note, we describe the proposed working parameter set for the KEK-SLAC ILC linear collider and discuss the reasons leading to the values listed; more ex- tensive discussion of the optimization process will be found in subsequent notes. The parameter set is listed in Table 1 and is compared with the JLC 3-97 parameters and the NLC ZDR parameters in Table 2. The new parameter set has an operating plane which ranges from low IP emittances and high luminosity (cases A) to large IP emittances and smaller luminosity (cases C). Over this range, the bunch charge, bunch length, and IP beta functions are varied, however, the parameters have been chosen so that the tolerances on the accelerating structures are roughly constant. The collider must be designed to operate over the entire parameter range. In all cases,

39

Exploring Quantum Physics at the ILC  

E-Print Network (OSTI)

We review the ILC capabilities to explore the electroweak (EW) sector of the SM at high precision and the prospects of unveiling signals of BSM physics, either through the presence of new particles in higher-order corrections or via direct production of extra EW gauge bosons. This includes electroweak precision observables, global fits to the SM Higgs boson mass as well as triple and quartic gauge boson couplings.

A. Freitas; K. Hagiwara; S. Heinemeyer; P. Langacker; K. Moenig; M. Tanabashi; G. W. Wilson

2013-07-15T23:59:59.000Z

40

Exploring Quantum Physics at the ILC  

E-Print Network (OSTI)

We review the ILC capabilities to explore the electroweak (EW) sector of the SM at high precision and the prospects of unveiling signals of BSM physics, either through the presence of new particles in higher-order corrections or via direct production of extra EW gauge bosons. This includes electroweak precision observables, global fits to the SM Higgs boson mass as well as triple and quartic gauge boson couplings.

Freitas, A; Heinemeyer, S; Langacker, P; Moenig, K; Tanabashi, M; Wilson, G W

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Glossary Term - Positron  

NLE Websites -- All DOE Office Websites (Extended Search)

Pluto Previous Term (Pluto) Glossary Main Index Next Term (Prometheus) Prometheus Positron A Positron The antimatter counterpart of the electron, positrons were discovered in 1932...

42

Elektron/Positron Annihilation  

NLE Websites -- All DOE Office Websites (Extended Search)

ElectronPositron Annihilation Teilchenzerfall und -vernichtung ElektronPositron Annihilation Wenn ein Elektron mit einem Positron (Antielektron) mit grosser Energie kollidiert,...

43

Photon Induced Positron Annihilation (PIPA) - Energy ...  

The photon source is directed toward a target to create positrons within it, ... Biomass and Biofuels; Building Energy Efficiency; Electricity Transmission;

44

About Fermilab | Fermilab and the Community | ILC Citizens' Task Force |  

NLE Websites -- All DOE Office Websites (Extended Search)

Expected Topics of the ILC Citizens' Task Force Topic Informal Input Community Concerns Formal Recomm. Orientation of the ILC Location of the underground tunnel X Community issues related to locating an underground tunnel X Potential impacts on groundwater and the environment X X Issues relating to property rights X X X Surface Structures off Fermilab property Locations X X Aesthetic issues X X Environmental impacts X X Features that could be included to benefit communities X X Construction of the ILC Timing of activities X X Safety X X Mitigating noise, traffic, environmental, and other impacts X X Fermilab-Community Relationships Maximizing economic benefits to the region X X

45

About Fermilab | Fermilab and the Community | ILC Citizens' Task Force |  

NLE Websites -- All DOE Office Websites (Extended Search)

2007 Meeting Calendar and Topics 2007 Meeting Calendar and Topics January 27, 2007 - Retreat and Tour March 1, 2007 - Particle Physics Overview of Particle Physics and Fermilab's contribution Introduction of Meeting Calendar March 27, 2007 - The ILC Introduction to the ILC May 1, 2007 - The Global Design Effort Conversation with GDE Director Barry Barish May 22, 2007 - Property Rights and Locating the ILC at Fermilab Understanding legal implications of property rights Identify criteria for siting Best orientations for the tunnel June 26, 2007 - Environmental Issues Managing potential environmental impacts of the ILC July 24, 2007 - Construction-Related Issues Timing Safety Mitigating impacts September 25, 2007 - Surface Structures Facility sizes and needs Aesthetic issues Features that could be included to benefit communities

46

ILC Marx Modulator Development Program Status  

DOE Green Energy (OSTI)

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.

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

2009-03-04T23:59:59.000Z

47

Coaxial Coupling Scheme for TESLA/ILC-type Cavities  

Science Conference Proceedings (OSTI)

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 TESLA/ILC operation conditions.

J.K. Sekutowicz, P. Kneisel

2010-05-01T23:59:59.000Z

48

Development Status of The ILC Marx Modulator  

SciTech Connect

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.

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

2010-06-07T23:59:59.000Z

49

Development Status of the ILC Marx Modulator  

DOE Green Energy (OSTI)

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.

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

2008-06-16T23:59:59.000Z

50

Experimental Aspects of Higgs Physics at the ILC  

SciTech Connect

Recent progress in Higgs boson studies for the International e{sup +}e{sup -} Linear Collider (ILC) is reported. These studies include extended simulations of the measurement of the Higgs mass, measurements of the Higgs boson branching ratios at higher center-of-mass energies, and methods for extracting the Higgs boson self-coupling. Also, the interplay between the LHC and the ILC in the measurement of the top Yukawa coupling and in the extraction of the supersymmetric Higgs sector parameters is discussed.

Barklow, T.

2004-11-16T23:59:59.000Z

51

Nondestructive examination using neutron activated positron annihilation  

SciTech Connect

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.

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

2001-01-01T23:59:59.000Z

52

Post LHC8 SUSY benchmark points for ILC physics  

E-Print Network (OSTI)

We re-evaluate prospects for supersymmetry at the proposed International Linear e^+e^- Collider (ILC) in light of the first two years of serious data taking at LHC: LHC7 with ~5 fb^{-1} of pp collisions at sqrt{s}=7 TeV and LHC8 with ~20 fb^{-1} at \\sqrt{s}=8 TeV. Strong new limits from LHC8 SUSY searches, along with the discovery of a Higgs boson with m_h~125 GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. After a review of the current status of supersymmetry, we present a variety of new ILC benchmark models, including: natural SUSY, radiatively-driven natural SUSY (RNS), NUHM2 with low m_A, a focus point case from mSUGRA/CMSSM, non-universal gaugino mass (NUGM) model, stau-coannihilation, Kallosh-Linde/spread SUSY model, mixed gauge-gravity mediation, normal scalar mass hierarchy (NMH), and one example with the recently discovered Higgs boson being the heavy CP-even state H. While all these models at present elude the latest LHC8 limits, they do offer intriguing case study possibilities for ILC operating at \\sqrt{s}~0.25-1 TeV. The benchmark points also present a view of the widely diverse SUSY phenomena which might still be expected in the post LHC8 era at both LHC and ILC.

Howard Baer; Jenny List

2013-07-02T23:59:59.000Z

53

Calorimetry for ILC Experiments: CALICE Collaboration R&D  

E-Print Network (OSTI)

The CALICE Collaboration is carrying out research and development into calorimetry for a detector at the International Linear Collider (ILC). CALICE is investigating a range of technologies for both electromagnetic and hadronic calorimetry. An overview of the prototypes and selected test-beam results are presented.

D. S. Bailey; for the CALICE Collaboration

2008-10-20T23:59:59.000Z

54

Design of the ILC RTML Extraction Lines  

SciTech Connect

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.

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

2011-10-17T23:59:59.000Z

55

ILC TARGET WHEEL RIM FRAGMENT/GUARD PLATE IMPACT ANALYSIS  

SciTech Connect

A positron source component is needed for the International Linear Collider Project. The leading design concept for this source is a rotating titanium alloy wheel whose spokes rotate through an intense localized magnetic field. The system is composed of an electric motor, flexible motor/drive-shaft coupling, stainless steel drive-shaft, two Plumber's Block tapered roller bearings, a titanium alloy target wheel, and electromagnet. Surrounding the target wheel and magnet is a steel frame with steel guarding plates intended to contain shrapnel in case of catastrophic wheel failure. Figure 1 is a layout of this system (guard plates not shown for clarity). This report documents the FEA analyses that were performed at LLNL to help determine, on a preliminary basis, the required guard plate thickness for three potential plate steels.

Hagler, L

2008-07-17T23:59:59.000Z

56

Triple $Z^0$-boson production in large extra dimensions model at ILC  

E-Print Network (OSTI)

We investigate the effects induced by the interactions of the Kaluza-Klein (KK) graviton with the standard model (SM) particles on the triple $Z^0$-boson production process at the ILC in the framework of the large extra dimension (LED) model. We present the dependence of the integrated cross sections on the electron-positron colliding energy $\\sqrt{s}$, and various kinematic distributions of final $Z^0$ bosons and their subsequential decay products in both the SM and the LED model. We also provide the relationship between the integrated cross section and the fundamental scale $M_S$ by taking the number of the extra dimensions ($d$) as 3, 4, 5, and 6, respectively. The numerical results show that the LED effect can induce a observable relative discrepancy for the integrated cross section ($\\delta_{LED}$), which can reach the value of $13.11% (9.27%)$ when $M_S = 3.5 (3.8) TeV$ and the colliding energy $\\sqrt{s} = 1 TeV$. We find the relative discrepancy of LED effect can even reach few dozen percent in the high transverse momentum area or the central rapidity region of the final $Z^0$-bosons and muons.

Jiang Ruo-Cheng; Li Xiao-Zhou; Ma Wen-Gan; Guo Lei; Zhang Ren-You

2012-11-29T23:59:59.000Z

57

High Availability Instrumentation Packaging Standards for the ILC and Detectors  

Science Conference Proceedings (OSTI)

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.

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

2006-11-30T23:59:59.000Z

58

Positron Emission Tomography (PET) and Positron Scanning  

Office of Scientific and Technical Information (OSTI)

DOE R&D Accomplishments DOE R&D Accomplishments Search All Database Web Pages for Go The Basics Home About What's New FAQ Contact Us Laureates Nobel Laureates Fermi Laureates Nobel Physicists Nobel Chemists Medicine Nobels Explore Insights SC Stories Snapshots R&D Nuggets Database Search Browse Reports Database Help Finding Aids Site Map A - Z Index Menu Synopsis Blog Archive QR Code RSS Archive Tag Cloud Videos Widget XML Bookmark and Share Positron Emission Tomography (PET) and Positron Scanning Resources with Additional Information Positron Emission Tomography (PET) Scanner Courtesy Lawrence Berkeley National Laboratory 'Positron Emission Tomography ... [is a medical imaging technique that] can track chemical reactions in living tissues and merges chemistry with biological imaging. Its strength has been in studies of the brain where there has been significant progress in investigations of drug addiction, aging, mental illness, and neurogenic disorders. Positron Emission Tomography (PET) had its genesis in hot-atom chemical research supported by the Chemical Sciences Division of the Office of Basic Energy Sciences. Through this research it was learned, over many years, how to prepare short-lived positron emitters such as 18F whose half-life is 110 minutes. In 1975, the molecule [18F]fluorodeoxyglucose was successfully synthesized at Brookhaven National Laboratory (BNL) and set the stage for Positron Emission Tomography of the human brain.'

59

Update on APS Upgrade Planning  

NLE Websites -- All DOE Office Websites (Extended Search)

Initiative Leader (via CARA). Activities spanned numerous Argonne divisions. This seed funding has led to direct ILC funding - FY06, Damping Ring, Positron Source - FY07,...

60

Coaxial Coupling Scheme for TESLA/ILC-type Cavities  

SciTech Connect

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.

J.K. Sekutowicz, P. Kneisel

2010-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

About Fermilab | Fermilab and the Community | ILC Citizens' Task Force |  

NLE Websites -- All DOE Office Websites (Extended Search)

Member Commitments Member Commitments It is anticipated that serving on the Task Force will require a commitment of 8-10 hours per month throughout 2007. Activities will include: Attend monthly meetings with a maximum of two excused absences Participate fully in meetings and work with all members to identify shared values and interests and strive for consensus on important issues Read all provided materials in preparation for meetings Read all materials and summaries for any meetings missed Stay in contact with neighbors and associates to bring broader community perspectives to the discussion and inform the community about the ILC Ground Rules This is a safe place to share ideas We will attack issues, never individuals Openness is the rule, not the exception Everyone participates

62

Configuration Studies and Recommendations for the ILC DampingRings  

Science Conference Proceedings (OSTI)

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.

Wolski, Andrzej; Gao, Jie; Guiducci, Susanna

2006-02-04T23:59:59.000Z

63

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

Science Conference Proceedings (OSTI)

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.

Harrison, M.

2011-04-30T23:59:59.000Z

64

Making Relativistic Positrons Using Ultra-Intense Short Pulse Lasers  

Science Conference Proceedings (OSTI)

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.

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

65

Making relativistic positrons using ultraintense short pulse lasers  

Science Conference Proceedings (OSTI)

This paper describes a new positron source using ultraintense short pulse lasers. Although it has been theoretically studied since 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 the Lawrence Livermore National Laboratory, a large number of positrons were observed after shooting a millimeter thick solid gold target. Up to 2x10{sup 10} positrons/s ejected at the back of approximately millimeter thick gold targets were detected. The targets were illuminated with short (approx1 ps) ultraintense (approx1x10{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 complement the existing sources based on radioactive isotopes and accelerators.

Chen Hui; Wilks, S. C.; Bonlie, J. D.; Chen, S. N.; Cone, K. V.; Elberson, L. N.; Price, D. F.; Schneider, M. B.; Shepherd, R.; Stafford, D. C.; Tommasini, R.; Van Maren, R.; Beiersdorfer, P. [Lawrence Livermore National Laboratory, Livermore, California 94550-9234 (United States); Gregori, G. [Clarendon Laboratory, University of Oxford, Oxford OX1 3PU (United Kingdom); Meyerhofer, D. D.; Myatt, J. [Laser Laboratory for Energetics, University of Rochester, Rochester, New York 14623 (United States)

2009-12-15T23:59:59.000Z

66

Optimization of the Low Loss SRF Cavity for the ILC  

SciTech Connect

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.

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

67

An Architecture Proposal for the ILC Test Beam Silicon Telescope at Fermilab  

SciTech Connect

The requirements for an ILC Test Beam silicon telescope system are foreseen to be very stringent. Resolution, noise, and throughput must be carefully managed in order to provide a useful instrument for the high energy physics community to develop detector technologies for the ILC. Since the ILC Test Beam is meant to test a wide variety of different detectors, it must employ universally accepted software techniques, hardware standards and protocols as well as easy integration of hardware and software with the various clients using the system. In this paper, we describe an open modular architecture to achieve these goals, including an analysis of the entire chain of software and hardware needed to meet the requirements.

Turqueti, M.A.; /Fermilab

2007-04-01T23:59:59.000Z

68

SIMULATION OF THE HIGGS BOSON PRODUCTION AT LHC, ILC AND PHOTON LINEAR COLLIDER ?  

E-Print Network (OSTI)

Prospects for precise determination of the Higgs boson couplings from a combined analysis of LHC, ILC and the Photon Linear Collider data are studied in detail for the CP-conserving Two Higgs Doublet Model (II). LHC, ILC and the Photon Collider measurements are complementary, being sensitive to different coupling combinations. For the mass of the heavy scalar Higgs boson between 200 and 350 GeV, where ZZ and W + W ? decaychannels dominate, only the combined analysis of the LHC, ILC and the Photon Collider data allows for unique determination of the basic Higgs boson couplings and for establishing evidence for the possible CP violation in 2HDM. Additional constraints on the model parameters can be obtained by combining available data for the production and decays of the heavy Higgs boson H with the corresponding measurements for the light Higgs boson h. PACS numbers: 11.15.Ex, 11.30.Er, 12.60.Fr, 14.80.Cp 1.

P. Nie?urawski; A. F. ?arnecki; M. Krawczyk

2006-01-01T23:59:59.000Z

69

Cosmic Ray Positrons at High Energies: A New Measurement  

E-Print Network (OSTI)

We present a new measurement of the cosmic-ray positron fraction e+/(e+ + e-) obtained from the first balloon flight of the High Energy Antimatter Telescope (HEAT). Using a magnet spectrometer combined with a transition radiation detector, an electromagnetic calorimeter, and time-of-flight counters we have achieved a high degree of background rejection. Our results do not indicate a major contribution to the positron flux from primary sources. In particular, we see no evidence for the significant rise in the positron fraction at energies above ~10 GeV previously reported.

HEAT Collaboration

1995-05-30T23:59:59.000Z

70

Anti-hydrogen production with positron beam ion trap  

Science Conference Proceedings (OSTI)

In low-energy antiproton physics, it is advantageous to be able to manipulate anti-particles as freely as normal particles. A robust production and storage system for high-quality positrons and antiprotons would be a substantial advance for the development of anti-matter science. The idea of electron beam ion trap could be applied for storage of anti-particle when the electron beam could be replaced by the positron beam. The bright positron beam would be brought about using synchrotron radiation source with a superconducting wiggler. The new scheme for production of anti-particles is proposed by using new accelerator technologies.

Itahashi, Takahisa [Department of Physics, Graduate School of Science, Osaka University 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan)

2008-08-08T23:59:59.000Z

71

Measuring the Magnetic Center Behavior of an ILC Superconducting Quadrupole Prototype  

SciTech Connect

The main linacs of the proposed International Linear Collider (ILC) consist of superconducting cavities operated at 2K. The accelerating cavities are contained in a contiguous series of cryogenic modules that also house the main linac quadrupoles, thus the quadrupoles also need to be superconducting. In an early ILC design, these magnets are about 0.6 m long, have cos (2{theta}) coils, and operate at constant field gradients up to 60 T/m. In order to preserve the small beam emittances in the ILC linacs, the e+ and e- beams need to traverse the quadrupoles near their magnetic centers. A quadrupole shunting technique is used to measure the quadrupole alignment with the beams; this process requires the magnetic centers move by no more than about 5 micrometers when their strength is changed. To determine if such tight stability is achievable in a superconducting quadrupole, we at SLAC measured the magnetic center motions in a prototype ILC quadrupole built at CIEMAT in Spain. A rotating coil technique was used with a better than 0.1 micrometer precision in the relative field center position, and less than a 2 micrometer systematic error over 30 minutes. This paper describes the warm-bore cryomodule that houses the quadrupole in its Helium vessel, the magnetic center measurement system, the measured center data and strength and harmonics magnetic data.

Spencer, Cherrill M.; Adolphsen, Chris; Berndt, Martin; Jensen, David R.; Rogers, Ron; Sheppard, John C.; Lorant, Steve St; Weber, Thomas B.; Weisend, John, II; /SLAC; Brueck, Heinrich; /DESY; Toral, Fernando; /Madrid, CIEMAT

2011-02-07T23:59:59.000Z

72

Positron Emission Tomography (PET)  

DOE R&D Accomplishments (OSTI)

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.

Welch, M. J.

1990-01-00T23:59:59.000Z

73

Sources  

NLE Websites -- All DOE Office Websites (Extended Search)

SOURCES Microsoft Corporation. "Gasohol," Microsoft Encarta Online Encyclopedia 2001, http:encarta.msn.com. U.S. Department of Transportation, Federal Highway Administration, A...

74

International linear collider reference design report  

E-Print Network (OSTI)

c) Radiation Safety System, SLAC, April, 2006. (d) FermilabPolarized Electron Sources”, SLAC-Pub 12249 (2006). DR [10]ILC Positron Source”, PAC05, SLAC-PUB-11767 (2005). [24] A.

Aarons, G.

2008-01-01T23:59:59.000Z

75

Positron Scanner for Locating Brain Tumors  

DOE R&D Accomplishments (OSTI)

A system is described that makes use of positron emitting isotopes for locating brain tumors. This system inherently provides more information about the distribution of radioactivity in the head in less time than existing scanners which use one or two detectors. A stationary circular array of 32 scintillation detectors scans a horizontal layer of the head from many directions simultaneously. The data, consisting of the number of counts in all possible coincidence pairs, are coded and stored in the memory of a Two-Dimensional Pulse-Height Analyzer. A unique method of displaying and interpreting the data is described that enables rapid approximate analysis of complex source distribution patterns. (auth)

Rankowitz, S.; Robertson, J. S.; Higinbotham, W. A.; Rosenblum, M. J.

1962-03-00T23:59:59.000Z

76

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

Science Conference Proceedings (OSTI)

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.

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

77

Controls, LLRF, and instrumentation systems for ILC test facilities at Fermilab  

Science Conference Proceedings (OSTI)

The major controls and instrumentation systems for the ILC test areas and the NML test accelerator at Fermilab are discussed. The test areas include 3 separate areas for Vertical Superconducting RF Cavity Testing, Horizontal Cavity Testing, and NML RF and beam test area. A common control infrastructure for the test areas including a controls framework, electronic logbook and cavity database will be provided, while supporting components supplied by collaborators with diverse areas of expertise (EPICS, DOOCS, LabVIEW, and Matlab). The discussions on the instrumentation systems are focused on overview and requirements.

Chase, B.; Votava, M.; Wendt, M.; /Fermilab

2007-06-01T23:59:59.000Z

78

Microsoft Word - Emittance Evolution of the Drive Electron Beam...  

NLE Websites -- All DOE Office Websites (Extended Search)

WF-NOTE-237 Dec. 21, 2007 Emittance Evolution of the Drive Electron Beam in Helical Undulator for ILC Positron Source Wanming Liu, Wei Gai, Michael Borland, Aimin Xiao, and...

79

Positron emitter labeled enzyme inhibitors  

DOE Patents (OSTI)

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.

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

80

Positron emitter labeled enzyme inhibitors  

DOE Patents (OSTI)

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.

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

1987-05-22T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

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

SciTech Connect

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.

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

2011-12-15T23:59:59.000Z

82

Electroweakino Searches: A Comparative Study for LHC and ILC (A Snowmass White Paper)  

E-Print Network (OSTI)

We make a systematic and comparative study for the LHC and ILC for the electroweakino searches in the Minimal Supersymmetric Standard Model. We adopt a general bottom-up approach and scan over the parameter regions for all the three cases of the lightest supersymmetric particle being Bino-, Wino-, and Higgsino-like. The electroweakino signal from pair production and subsequent decay to Wh (h to b\\bar b) final state may yield a sensitivity of 95% C.L. exclusion (5sigma discovery) to the mass scale M_2, mu ~ 250-400 GeV (200-250 GeV) at the 14 TeV LHC with an luminosity of 300 fb^{-1}. Combining with all the other decay channels, the 95% C.L. exclusion (5sigma discovery) may be extended to M_2, mu ~ 480-700 GeV (320-500 GeV). At the ILC, the electroweakinos could be readily discovered once the kinematical threshold is crossed, and their properties could be thoroughly studied.

Mikael Berggren; Tao Han; Jenny List; Sanjay Padhi; Shufang Su; Tomohiko Tanabe

2013-09-27T23:59:59.000Z

83

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

SciTech Connect

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.

Seletskiy, S.; Solyak, N.

2011-03-28T23:59:59.000Z

84

A comparative study of non-Gaussianity in ILC-7yr CMB map  

E-Print Network (OSTI)

A detection or non detection of primordial non--Gaussianity (NG) by using the cosmic microwave background radiation (CMB) is a possible way to break the degeneracy of early universe models. Since a single statistical estimator hardly can be sensitive to all possible forms of NG which may be present in the data, it is important to use different statistical estimators to study NG in CMB. Recently, two new large-angle NG indicators based on skewness and kurtosis of spherical caps or spherical cells of CMB sky have been proposed and used in both CMB data and simulated maps. Here, we make a comparative study of these two different procedures by examining the NG in the WMAP seven years ILC map. We show that the spherical cells procedure detects a higher level of NG than that obtained by the method with overlapping spherical caps.

W. A. Cardona; A. Bernui; M. J. Reboucas

2013-05-25T23:59:59.000Z

85

R&D for Very Forward Calorimeters at the ILC Detector  

E-Print Network (OSTI)

Special calorimeters are needed to instrument the very forward region of an ILC detector. These devices will improve the hermeticity being important for new particle searches. A luminometer is foreseen to measure the rate of low angle Bhabha scattering with a precision better than 10-3. A calorimeter adjacent to the beam-pipe will be hit by a large amount of beamstrahlung remnants. The amount and shape of these depositions will allow a fast luminosity estimate and the determination of beam parameters. However, the sensors must be extremely radiation hard. Finely segmented and very compact calorimeters will match the requirements. Due to the high occupancy fast FE electronics is needed. A possible design of the calorimeters is presented and an overview on the R&D status is given

W. Lohmann

2009-02-19T23:59:59.000Z

86

Projections for Two Higgs Doublet Models at the LHC and ILC: A Snowmass White Paper  

E-Print Network (OSTI)

The discovery of the 125 GeV Higgs boson and the measurement of its branching ratios has initiated the exploration of the electroweak symmetry breaking sector. There have been numerous studies exploring the restrictions these results place on the parameter space of two Higgs doublet models. We extend these results to include the full data set and study the expected sensitivity that can be obtained with 300 and 3000 inverse femtobarn of integrated luminosity. In addition, searches for a heavy Standard Model Higgs boson are also considered. It is shown that the nonobservation of such a Higgs boson can substantially narrow the allowed regions of parameter space in two Higgs doublet models. Finally, projections for the ILC at the center of mass energy 250, 500, and 1000 GeV are investigated.

Chien-Yi Chen

2013-08-15T23:59:59.000Z

87

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

Science Conference Proceedings (OSTI)

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.

Wang, Lanfa; Pivi, Mauro; /SLAC

2012-05-30T23:59:59.000Z

88

Longitudinal Single-Bunch Instability in the ILC Damping Rings: Estimate of Current Threshold  

SciTech Connect

Characterization of single-bunch instabilities in the International Linear Collider (ILC) damping rings (DRs) has been indicated as a high-priority activity toward completion of an engineering design. In this paper we report on a first estimate ofthe current thresholds for the instability using numerical and analytical models of the wake potentials associated with the various machine components. The numerical models were derived (upon appropriate scaling) from designs of the correspondingcomponents installed in existing machines. The current thresholds for instabilities were determined by numerical solution of the Vlasov equation for the longitudinal dynamics. For the DR baseline lattice as of Feb. 2007 we find the critical current forinstability to be safely above the design specifications leaving room for further optimization of the choice of the momentum compaction.

Venturini, Marco; Venturini, Marco

2008-06-25T23:59:59.000Z

89

Constraining the origin of the rising cosmic ray positron fraction with the boron-to-carbon ratio  

E-Print Network (OSTI)

The rapid rise in the cosmic ray positron fraction above 10 GeV, as measured by PAMELA and AMS, suggests the existence of nearby primary sources of high energy positrons, such as pulsars or annihilating/decaying dark matter. In contrast, the spectrum of secondary positrons produced through the collisions of cosmic rays in the interstellar medium is predicted to fall rapidly with energy, and thus is unable to account for the observed rise. It has been proposed, however, that secondary positrons could be produced and then accelerated in nearby supernova remnants, potentially explaining the observed rise, without the need of primary positron sources. Yet, if secondary positrons are accelerated in such shocks, other secondary cosmic ray species (such as boron nuclei, and antiprotons) will also be accelerated, leading to rises in the boron-to-carbon and antiproton-to-proton ratios. The measurements of the boron-to-carbon ratio by the PAMELA and AMS collaborations, however, show no sign of such a rise. With this new data in hand, we revisit the secondary acceleration scenario for the rising positron fraction. Assuming that the same supernova remnants accelerate both light nuclei (protons, helium) and heavier cosmic ray species, we find that no more than ~25% of the observed rise in the positron fraction can result from this mechanism (at the 95% confidence level)

Ilias Cholis; Dan Hooper

2013-12-10T23:59:59.000Z

90

The Energy Spectra and Relative Abundances of Electrons and Positrons in the Galactic Cosmic Radiation  

E-Print Network (OSTI)

Observations of cosmic-ray electrons and positrons have been made with a new balloon-borne detector, HEAT (the "High-Energy Antimatter Telescope"), first flown in 1994 May from Fort Sumner, NM. We describe the instrumental approach and the data analysis procedures, and we present results from this flight. The measurement has provided a new determination of the individual energy spectra of electrons and positrons from 5 GeV to about 50 GeV, and of the combined "all-electron" intensity (e+ + e-) up to about 100 GeV. The single power-law spectral indices for electrons and positrons are alpha = 3.09 +/- 0.08 and 3.3 +/- 0.2, respectively. We find that a contribution from primary sources to the positron intensity in this energy region, if it exists, must be quite small.

S. W. Barwick; J. J. Beatty; C. R. Bower; C. J. Chaput; S. Coutu; G. A. de Nolfo; M. A. DuVernois; D. Ellithorpe; D. Ficenec; J. Knapp; D. M. Lowder; S. McKee; D. Muller; J. A. Musser; S. L. Nutter; E. Schneider; S. P. Swordy; G. Tarle; A. D. Tomasch; E. Torbet

1997-12-24T23:59:59.000Z

91

Conventional Positron Target for a Tesla Formatted Beam  

NLE Websites -- All DOE Office Websites (Extended Search)

3 3 SLAC-TN-03-072 November 2003 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Conventional Positron Target for a Tesla Formatted Beam John C. Sheppard Stanford Linear Accelerator Center

92

Electron and positron pair production of compact stars  

E-Print Network (OSTI)

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.

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

2011-10-04T23:59:59.000Z

93

Induced Positron Annihiliation Investigation of Cadmium Zinc Telluride Crystal Microstructures  

Science Conference Proceedings (OSTI)

Cadmium-Zinc-Telluride (CZT) crystals are used in semiconductor radiation detectors for the detection of x-ray and gamma radiation. However, production of detector grade crystals is difficult as small variations in compositional uniformity and primarily the zinc content can significantly affect the ability of the CZT crystal to function as a radiation detector. Currently there are no known nondestructive methods that can be used to identify detector grade crystals. The current test method is to fabricate and test the detector to determine if the crystal is sufficiently uniform and of the correct composition to be considered a detector grade crystal. Consequently, nondestructive detection methods are needed to identify detector grade crystals prior to the fabrication process. The purpose of this feasibility study was to perform a preliminary assessment of the ability of several new, nondestructive technologies based on Induced Positron Annihilation (IPA) to determine if detector grade CZT crystals can be identified. Results of measurements performed on specimens from Fisk University and EV Products, Inc. indicate that both the near surface Distributed Source Positron Annihilation (up to 3 mm penetration) and the volumetric Photon Induced Positron Annihilation methods may be suitable for determining CZT crystal quality. Further work on CZT crystals with a broader range of compositions and detector characteristics is needed to provide a well defined, calibrated, method for assessing CZT crystal quality.

D. W. Akers

2005-06-01T23:59:59.000Z

94

Optimization of the Low-Loss SRF Cavity for the ILC  

SciTech Connect

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.

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

95

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

SciTech Connect

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

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

96

Study of electron-positron interactions  

SciTech Connect

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.

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

1990-09-15T23:59:59.000Z

97

Intense low energy positron beams  

Science Conference Proceedings (OSTI)

Intense positron beams are under development or being considered at several laboratories. Already today a few accelerator based high intensity, low brightness e{sup +} beams exist producing of the order of 10{sup 8} {minus} 10{sup 9} e{sup +}/sec. Several laboratories are aiming at high intensity, high brightness e{sup +} beams with intensities greater than 10{sup 9} e{sup +}/sec and current densities of the order of 10{sup 13} {minus} 10{sup 14} e{sup +} sec{sup {minus}} {sup 1}cm{sup {minus}2}. Intense e{sup +} beams can be realized in two ways (or in a combination thereof) either through a development of more efficient B{sup +} moderators or by increasing the available activity of B{sup +} particles. In this review we shall mainly concentrate on the latter approach. In atomic physics the main trust for these developments is to be able to measure differential and high energy cross-sections in e{sup +} collisions with atoms and molecules. Within solid state physics high intensity, high brightness e{sup +} beams are in demand in areas such as the re-emission e{sup +} microscope, two dimensional angular correlation of annihilation radiation, low energy e{sup +} diffraction and other fields. Intense e{sup +} beams are also important for the development of positronium beams, as well as exotic experiments such as Bose condensation and Ps liquid studies.

Lynn, K.G.; Jacobsen, F.M.

1993-12-31T23:59:59.000Z

98

Positron-diffraction experiments with a brightness-enhanced slow positron beam  

Science Conference Proceedings (OSTI)

The construction of a high brightness slow positron beam has enabled us to extend Low Energy Positron Diffraction (LEPD) measurements well beyond the previously accessible range of energies. Details of the design and construction of this beam, which utilizes two stages of reflection remoderation for a 500-fold increase in brightness-per-volt, are presented, with emphasis on the positron optics. The positron beam is maintained in an ultra-high vacuum environment. This, together with the inclusion of facilities for display LEED and Auger Electron Spectroscopy, make the apparatus well suited for surface studies. Two sets of experiments performed with this new apparatus are described. Measurements of the specularly diffracted intensity from Cu(001) and Cu(111) single crystals show large peaks in the previously inaccessible 10-30 volt range. These peaks are well displaced from the kinematic Bragg positions and may be influenced by the emergence of non-specular diffraction beams, but the sharp series of features characteristic of beam threshold effects has not been observed. In the second set of experiments neutral positronium atom production is measured as a function of incident positron energy. The observed positronium production is correlated to the intensity vs. energy spectrum for diffracted positrons, suggesting that positronium formation is an important channel for elastically scattered positrons. The angular distribution of positronium formed changes with incident beam energy and may contain information on the details of the potential in the surface region.

Lippel, P.H.

1988-01-01T23:59:59.000Z

99

An Undulator based Polarized Positron Source for CLIC  

NLE Websites -- All DOE Office Websites (Extended Search)

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...

100

Discriminators of 2 Higgs Doublets at the LHC14, ILC and MuonCollider(125): A Snowmasss White Paper  

E-Print Network (OSTI)

The historic LHC discovery of the 125 GeV particle with properties that closely resemble the Standard Model (SM) Higgs boson verifies our understanding of electroweak symmetry breaking, but solidifies the need for a resolution to the hierarchy problem. Many extensions of the SM that address the hierarchy problem contain a non-minimal Higgs sector. Therefore, as a benchmark alternative to the SM Higgs mechanism, we study a general 2 Higgs doublet model (2HDM-G) framework for evaluating future sensitivity to Higgs couplings. We study how well it can be distinguished from the SM Higgs boson by future measurements at LHC14, ILC (250, 500,1000 GeV) and a Muon Collider (125 GeV). Additionally, our study bears on singlet Higgs extensions of two Higgs doublet models through predicted coupling relationships.

Vernon Barger; Lisa L. Everett; Heather E. Logan; Gabe Shaughnessy

2013-07-13T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Advanced Instrumentation for Positron Emission Tomography [PET  

DOE R&D Accomplishments (OSTI)

This paper summarizes the physical processes and medical science goals that underlay modern instrumentation design for Positron Emission Tomography. The paper discusses design factors such as detector material, crystalphototube coupling, shielding geometry, sampling motion, electronics design, time-of-flight, and the interrelationships with quantitative accuracy, spatial resolution, temporal resolution, maximum data rates, and cost.

Derenzo, S. E.; Budinger, T. F.

1985-04-00T23:59:59.000Z

102

Relativistic Positron Creation Using Ultraintense Short Pulse Lasers  

Science Conference Proceedings (OSTI)

We measure up to 2x10{sup 10} positrons per steradian ejected out the back of {approx}mm thick gold targets when illuminated with short ({approx}1 ps) ultraintense ({approx}1x10{sup 20} W/cm{sup 2}) laser pulses. Positrons are 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. Modeling based on the measurements indicate the positron density to be {approx}10{sup 16} positrons/cm{sup 3}, the highest ever created in the laboratory.

Chen Hui; Wilks, Scott C.; Bonlie, James D.; Price, Dwight F.; Beiersdorfer, Peter [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Liang, Edison P. [Rice University, Houston, Texas 77005 (United States); Myatt, Jason; Meyerhofer, David D. [University of Rochester, Rochester, New York 14623 (United States)

2009-03-13T23:59:59.000Z

103

Positron Beam Propagation in a Meter Long Plasma Channel  

SciTech Connect

Recent experiments and simulations have shown that positron beams propagating in plasmas can be focused and also create wakes with large accelerating gradients. For similar parameters, the wakes driven by positron beams are somewhat smaller compared to the case of an electron beam. Simulations have shown that the wake amplitude can be increased if the positron beam is propagated in a hollow plasma channel (Ref. 1). This paper, compares experimentally, the propagation and beam dynamics of a positron beam in a meter scale homogeneous plasma, to a positron beam hollow channel plasma. The results show that positron beams in hollow channels are less prone to distortions and deflections. Hollow channels were observed to guide the positron beam onto the channel axis. Beam energy loss was also observed implying the formation of a large wake amplitude. The experiments were carried out as part of the E-162 plasma wakefield experiments at SLAC.

Marsh, K.A.; Blue, B.E.; Clayton, C.E.; Joshi, C.; Mori, W.B.; /UCLA; Decker, F.-J.; Hogan, M.J.; Iverson, R.; O' Connell, C.; Raimondi, P.; Siemann, Robert H.; Walz, D.; /SLAC; Katsouleas, T.C.; Muggli, P.; /Southern California U.

2008-03-17T23:59:59.000Z

104

Qualification of the Second Batch Production 9-Cell Cavities Manufactured by AES and Validation of the First US Industrial Cavity Vendor for ILC  

SciTech Connect

One of the major goals of ILC SRF cavity R&D is to develop industrial capabilities of cavity manufacture and processing in all three regions. In the past several years, Jefferson Lab, in collaboration with Fermi National Accelerator Laboratory, has processed and tested all the 9-cell cavities of the first batch (4 cavities) and second batch (6 cavities) production cavities manufactured by Advanced Energy Systems Inc. (AES). Over the course, close information feedback was maintained, resulting in changes in fabrication and processing procedures. A light buffered chemical polishing was introduced, removing the weld splatters that could not be effectively removed by heavy EP alone. An 800 Celsius 2 hour vacuum furnace heat treatment procedure replaced the original 600 Celsius 10 hour procedure. Four out of the six 9-cell cavities of the second production bath achieved a gradient of 36-41 MV/m at a Q0 of more than 8·109 at 35 MV/m. This result validated AES as the first “ILC certified” industrial vendor in the US for ILC cavity manufacture.

Geng, R L; Golden, B A; Kushnick, P; Overton, R B; Calderaro, M; Peterson, E; Rathke, J; Champion, M S; Follkie, J

2011-07-01T23:59:59.000Z

105

Low-energy electron and low-energy positron holography  

Science Conference Proceedings (OSTI)

We demonstrate holographic reconstruction using low-energy electron-diffraction (LEED) and low-energy positron-diffraction (LEPD) intensity spectra. Calculated LEED and LEPD intensity spectra from a multiple-scattering method are inverted to produce high-fidelity images of near-neighbor atoms whose positions are measured from an adatom. We show that low-energy positron diffraction is better suited for holographic reconstruction because positron scattering in solids is weaker than that of electrons.

Tong, S.Y.; Huang, H.; Guo, X.Q. (Laboratory for Surface Studies and Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201 (United States))

1992-12-21T23:59:59.000Z

106

Extragalactic Point Source Search in Five-year WMAP 41, 61 and 94 GHz Maps  

E-Print Network (OSTI)

We present the results of an extragalactic point source search using the five-year WMAP 41, 61 and 94 GHz (Q-, V- and W-band) temperature maps. This work is an extension of our point source search in the WMAP maps applying a CMB-free technique. An internal linear combination (ILC) map has been formed from the three-band maps, with the weights chosen to remove the CMB anisotropy signal as well as to favor a selection of flat-spectrum sources. We find 381 sources at the > 5 sigma level outside the WMAP point source detection mask in the ILC map, among which 89 are "new" (i.e., not present in the WMAP catalog). Source fluxes have been calculated and corrected for the Eddington bias. We have solidly identified 367 (96.3%) of our sources. The 1 sigma positional uncertainty is estimated to be 2'. The 14 unidentified sources could be either extended radio structure or obscured by Galactic emission. We have also applied the same detection process on simulated maps and found 364+/-21 detections on average. The recovered source distribution N(>S) agrees well with the simulation input, which proves the reliability of this method.

Xi Chen; Edward L. Wright

2008-09-23T23:59:59.000Z

107

Pair production of Higgs bosons associated with $Z$ boson in the left-right twin Higgs model at the ILC  

E-Print Network (OSTI)

The left-right twin Higgs(LRTH) model predicts the existence of three additional Higgs bosons: one neutral Higgs $\\phi^{0}$ and a pair of charged Higgs bosons $\\phi^{\\pm}$. In this paper, we studied the production of a pair of charged and neutral Higgs bosons associated with standard model gauge boson $Z$ at the ILC, i.e., $e^{+}e^{-}\\rightarrow Z\\phi^{+}\\phi^{-}$ and $e^{+}e^{-}\\rightarrow Z\\phi^{0}\\phi^{0}$. We calculate the production rate and present the distributions of the various observables, such as, the distributions of the energy and the transverse momenta of final $Z$-boson and charged Higgs boson $\\phi^{-}$, the differential cross section of the invariant mass of charged Higgs bosons pair, the distribution of the angle between charged Higgs bosons pair and the production angle distributions of $Z$-boson and charged Higgs boson $\\phi^{-}$. Our numerical results show that, for the process $e^{+}e^{-}\\rightarrow Z\\phi^{+}\\phi^{-}$, the production rates are at the level of $10^{-1} fb$ with reasonable parameter values. For the process of $e^{+}e^{-}\\rightarrow Z\\phi^{0}\\phi^{0}$, we find that the production cross section are smaller than $6\\times 10^{-3} fb$ in most of parameter space. However, the resonance production cross section can be significantly enhanced.

Yao-Bei Liu; Xue-Lei Wang

2010-06-23T23:59:59.000Z

108

Supersymmetry and the Cosmic Ray Positron Excess  

SciTech Connect

We explore several supersymmetric alternatives to explain predictions for the cosmic ray positron excess. Light sneutrino or neutralino LSP's, and a fine-tuned model designed to provide a delta-function input, can give adequate statistical descriptions of the reported HEAT data if non-thermal production of the relic cold dark matter density dominates and/or if"boost factors" (that could originate in uncertainties from propagation or local density fluctuations) to increase the size of the signal are included. All the descriptions can be tested at the Tevatron or LHC, and some in other WIMP detecting experiments.

Kane, Gordon L.; Wang, Lian-Tao; Wang, Ting T.

2002-02-15T23:59:59.000Z

109

High Energy Positrons From Annihilating Dark Matter  

E-Print Network (OSTI)

Recent preliminary results from the PAMELA experiment indicate the presence of an excess of cosmic ray positrons above 10 GeV. In this letter, we consider possibility that this signal is the result of dark matter annihilations taking place in the halo of the Milky Way. Rather than focusing on a specific particle physics model, we take a phenomenological approach and consider a variety of masses and two-body annihilation modes, including W+W-, ZZ, b bbar, tau+ tau-, mu+ mu-, and e+e. We also consider a range of diffusion parameters consistent with current cosmic ray data. We find that a significant upturn in the positron fraction above 10 GeV is compatible with a wide range of dark matter annihilation modes, although very large annihilation cross sections and/or boost factors arising from inhomogeneities in the local dark matter distribution are required to produce the observed intensity of the signal. We comment on constraints from gamma rays, synchrotron emission, and cosmic ray antiproton measurements.

Ilias Cholis; Lisa Goodenough; Dan Hooper; Melanie Simet; Neal Weiner

2008-09-10T23:59:59.000Z

110

Positron emission tomography of the heart  

SciTech Connect

Positron emission computed tomography (PCT) represents an important new tool for the noninvasive evaluation and, more importantly, quantification of myocardial performance. Most currently available techniques permit assessment of only one aspect of cardiac function, i.e., myocardial perfusion by gamma scintillation camera imaging with Thallium-201 or left ventricular function by echocardiography or radionuclide angiocardiography. With PCT it may become possible to study all three major segments of myocardial performance, i.e., regional blood flow, mechanical function and, most importantly, myocardial metabolism. Each of these segments can either be evaluated separately or in combination. This report briefly describes the principles and technological advantages of the imaging device, reviews currently available radioactive tracers and how they can be employed for the assessment of flow, function and metabolism; and, lastly, discusses possible applications of PCT for the study of cardiac physiology or its potential role in the diagnosis of cardiac disease.

Schelbert, H.R.; Phelps, M.E.; Kuhl, D.E.

1979-01-01T23:59:59.000Z

111

Positive muon and the positron as probes of defects  

SciTech Connect

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.

Lynn, K G

1980-01-01T23:59:59.000Z

112

Positron Computed Tomography: Current State, Clinical Results and Future Trends  

DOE R&D Accomplishments (OSTI)

An overview is presented of positron computed tomography: its advantages over single photon emission tomography, its use in metabolic studies of the heart and chemical investigation of the brain, and future trends. (ACR)

Schelbert, H. R.; Phelps, M. E.; Kuhl, D. E.

1980-09-00T23:59:59.000Z

113

PhytoBeta imager: a positron imager for plant biology  

SciTech Connect

Several positron emitting radioisotopes such as 11C and 13N can be used in plant biology research. The 11CO2 tracer is used to facilitate plant biology research toward optimization of plant productivity, biofuel development and carbon sequestration in biomass. Positron emission tomography (PET) imaging has been used to study carbon transport in live plants using 11CO2. Because plants typically have very thin leaves, little medium is present for the emitted positrons to undergo an annihilation event. The emitted positrons from 11C (maximum energy 960 keV) could require up to approximately 4 mm of water equivalent material for positron annihilation. Thus many of the positrons do not annihilate inside the leaf, resulting in limited sensitivity for PET imaging. To address this problem we have developed a compact beta-positive, beta-minus particle imager (PhytoBeta imager) for 11CO2 leaf imaging. The detector is based on a Hamamatsu H8500 position sensitive photomultiplier tube optically coupled via optical grease to a 0.5 mm thick Eljen EJ-212 plastic scintillator. The detector is equipped with a flexible arm to allow its placement and orientation over or under the leaf to be studied while maintaining the leaf's original orientation. To test the utility of the system the detector was used to measure carbon translocation in a leaf of the spicebush (Lindera benzoin) under two transient light conditions.

Weisenberger, Andrew G; Lee, Seungjoon; McKisson, John; McKisson, J E; Xi, Wenze; Zorn, Carl; Reid, Chantal D; Howell, Calvin R; Crowell, Alexander S; Cumberbatch, Laurie; Fallin, Brent; Stolin, Alexander

2012-06-01T23:59:59.000Z

114

Dissecting cosmic-ray electron-positron data with Occam's Razor: the role of known Pulsars  

E-Print Network (OSTI)

We argue that both the positron fraction measured by PAMELA and the peculiar spectral features reported in the total electron-positron (e+e-) flux measured by ATIC have a very natural explanation in electron-positron pairs produced by nearby pulsars. While this possibility was pointed out a long time ago, the greatly improved quality of current data potentially allow to reverse-engineer the problem: given the regions of pulsar parameter space favored by PAMELA and by ATIC, are there known pulsars that explain the data with reasonable assumptions on the injected e+e- pairs? In the context of simple benchmark models for estimating the e+e- output, we consider all known pulsars, as listed in the most complete available catalogue. We find that it is unlikely that a single pulsar be responsible for both the PAMELA e+ fraction anomaly and for the ATIC excess, although two single sources are in principle enough to explain both experimental results. The PAMELA excess e+ likely come from a set of mature pulsars (age ~ 10^6 yr), with a distance of 0.8-1 kpc, or from a single, younger and closer source like Geminga. The ATIC data require a larger (and less plausible) energy output, and favor an origin associated to powerful, more distant (1-2 kpc) and younger (age ~ 10^5$ yr) pulsars. We list several candidate pulsars that can individually or coherently contribute to explain the PAMELA and ATIC data. Although generally suppressed, we find that the contribution of pulsars more distant than 1-2 kpc could contribute for the ATIC excess. Finally, we stress the multi-faceted and decisive role that Fermi-LAT will play in the very near future by (1) providing an exquisite measurement of the e+e- flux, (2) unveiling the existence of as yet undetected pulsars, and (3) searching for anisotropies in the arrival direction of high-energy e+e-.

Stefano Profumo

2008-12-23T23:59:59.000Z

115

Status of the advanced photon source  

SciTech Connect

This report presents general information on the Advanced Photon Source (APS) and then breaks down the APS project into three categories: accelerator systems, experimental facilities, and conventional facilities. The accelerator systems consist of the 7 GeV APS positron storage ring and a 7 GeV positron injector. The experimental facilities include 20 undulator radiation sources and the x-ray beamline components necessary to transport their extraordinarily intense x-ray beams outside the accelerator enclosure. Also included are x-ray beamline components for 20 bending magnet radiation sources. The conventional facilities consist of the accelerator enclosures, a 35,300 m{sup 2} experimental hall to house the x-ray beamlines, an office building for the APS staff and lab/office facilities for the research groups which will construct and operate the first 40 beamlines. APS users are described, and the properties of synchrotron radiation are discussed.

Galayda, J.

1996-12-31T23:59:59.000Z

116

Delayed ILC Roadmap  

NLE Websites -- All DOE Office Websites (Extended Search)

Comments: both Argonne and FNAL had and have summer students openings to work on accelerators E.g. FNAL has an International Program (accelerators only, 8-10 yr) and...

117

Positron Accumulator Ring (PAR) power supply  

SciTech Connect

The Positron Accumulator Ring (PAR) consists of 8 dipole magnets connected in series. These magnets are energized via one 12-pulse dc power supply. The power supply consists of four phase controlled half-wave wye group converters. Each of the two half-wave converters are connected through an interphase transformer to obtain a full-wave converter with 120{degrees} conduction. The input voltage for these two half-wave converters are 180{degrees} apart. The two full-wave converters are connected in parallel through a third interphase transformer. This type of connection of the converters not only provides the required output current, it also improves the input power factor of the power supply. The output of the wye group converters is filtered through a passive L-R-C filter to reduce the ripple content of the output current. At low current values of the power supply the current ripple is high, thus a large filter is needed, which adds to the cost of the power supply, however at high output current levels, the current ripple is less severe. The large size of the filter can be reduced by adding an anti-parallel rectifier diode(D1) to the output of the power supply. A freewheeling diode(D2) is connected before the choke to circulate the current once the power supply is turned off. In order to measure the current in the magnet a high precision, low drift, zero flux current transductor is used. This transductor senses the magnet current which provides a feedback signal to control the gating of the converter`s thyristors. A true 14 bit Digital to Analog Converter (DAC) is programmed by the control computer for the required current value, providing a reference for the current regulator. Fast correction of the line transients is provided by a relatively fast voltage loop controlled by a high gain slow response current loop.

Fathizadeh, M.

1995-08-01T23:59:59.000Z

118

Compact Beta Particle/Positron Imager for Plant Biology  

Science Conference Proceedings (OSTI)

The 11CO2 tracer is used to facilitate plant biology research towards optimization of plant productivity, biofuel development and carbon sequestration in biomass. Positron emission tomography (PET) imaging has been used to study carbon transport in live plants using 11CO2. Plants typically have very thin leaves resulting in little medium for the emitted positrons to undergo an annihilation event. For the emitted positron from 11C decay approximately 1mm of water equivalent material is needed for positron annihilation. Thus most of the positrons do not annihilate inside the leaf, resulting in limited sensitivity for PET imaging. To address this problem we have developed a compact beta-positive beta-minus particle (BPBM) imager for 11CO2 leaf imaging. The detector is based on a Hamamatsu H8500 position sensitive photomultiplier tube optically coupled via optical grease and a 3mm thick glass plate to a 0.5mm thick Eljin EJ-212 plastic scintillator. The detector is equipped with a flexible arm to allow its placement and orientation on the leaf of the plant of interest while maintaining the leaf's original orientation. We are planning to utilize the imaging device at the Duke University Phytotron to investigate dynamic carbon transport differences between invasive and native species.

Weisenberger, Andrew; Lee, Seung Joon; McKisson, John; Xi, Wenze; Zorn, Carl; Stolin, Alexander; Majewski, Stan; Majewski, Stanislaw; Howell, Calvin; Crowell, Alec

2011-06-01T23:59:59.000Z

119

Recent progress in tailoring trap-based positron beams  

SciTech Connect

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.

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

120

Inelastic cross sections for positron scattering from atomic hydrogen  

DOE Green Energy (OSTI)

Positronium formation (Ps) cross sections for positrons impinging on atomic hydrogen were measured in the impact energy range from 13eV to 255eV at the High Intensity Positron (HIP) beam at Brookhaven National Laboratory (BNL). The Ps-formation cross section was found to rise rapidly from the threshold at 6.8eV to a maximum value of (2.98 {plus_minus} 0.18) {times} 10{sup {minus}16} cm{sup 2} for {approx} 15eV positrons. By 75eV it drops below the detection limit of 0.17 {times} 10{sup {minus}16} cm{sup 2} which is the present level of statistical uncertainty. The experiment was modified to enable the measurement of doubly differential scattering cross sections.

Weber, M.; Hofmann, A.; Raith, W.; Sperber, W. [Bielefeld Univ. (Germany). Fakultaet fuer Physik; Jacobsen, F.; Lynn, K.G. [Brookhaven National Lab., Upton, NY (United States)

1994-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Annihilating dark matter and the galactic positron excess  

E-Print Network (OSTI)

The possibility that the Galactic dark matter is composed of neutralinos that are just above half the $Z^o$ mass is examined, in the context of the Galactic positron excess. In particular, we check if the anomalous bump in the cosmic ray positron to electron ratio at $10~GeV$ can be explained with the ``decay'' of virtual $Z^o$ bosons produced when the neutralinos annihilate. We find that the low energy behaviour of our prediction fits well the existing data. Assuming the neutralinos annihilate primarily in the distant density concentration in the Galaxy and allowing combination of older, diffused positrons with young free-streaming ones, produces a fit which is not satisfactory on its own but is significantly better than the one obtained with homogeneous injection.

Irit Maor

2006-02-20T23:59:59.000Z

122

Electron-positron pairs production in a macroscopic charged core  

E-Print Network (OSTI)

Classical and semi-classical energy states of relativistic electrons bounded by a massive and charged core with the charge-mass-radio Q/M and macroscopic radius R_c are discussed. We show that the energies of semi-classical (bound) states can be much smaller than the negative electron mass-energy (-mc^2), and energy-level crossing to negative energy continuum occurs. Electron-positron pair production takes place by quantum tunneling, if these bound states are not occupied. Electrons fill into these bound states and positrons go to infinity. We explicitly calculate the rate of pair-production, and compare it with the rates of electron-positron production by the Sauter-Euler-Heisenberg-Schwinger in a constant electric field. In addition, the pair-production rate for the electro-gravitational balance ratio Q/M = 10^{-19} is much larger than the pair-production rate due to the Hawking processes.

Ruffini, Remo

2011-01-01T23:59:59.000Z

123

Electron-positron pairs production in a macroscopic charged core  

E-Print Network (OSTI)

Classical and semi-classical energy states of relativistic electrons bounded by a massive and charged core with the charge-mass-radio Q/M and macroscopic radius R_c are discussed. We show that the energies of semi-classical (bound) states can be much smaller than the negative electron mass-energy (-mc^2), and energy-level crossing to negative energy continuum occurs. Electron-positron pair production takes place by quantum tunneling, if these bound states are not occupied. Electrons fill into these bound states and positrons go to infinity. We explicitly calculate the rate of pair-production, and compare it with the rates of electron-positron production by the Sauter-Euler-Heisenberg-Schwinger in a constant electric field. In addition, the pair-production rate for the electro-gravitational balance ratio Q/M = 10^{-19} is much larger than the pair-production rate due to the Hawking processes.

Remo Ruffini; She-Sheng Xue

2011-06-24T23:59:59.000Z

124

Low-energy positron diffraction from GaAs(110)  

Science Conference Proceedings (OSTI)

Intensities of 16 beams of near normal incidence positrons have been measured at {ital T}=120 K and analyzed using a multiple scattering model of the low-energy positron diffraction (LEPD) process. Excellent correspondence between the measured and calculated intensities is obtained for a reconstruction that is primarily a bond-length-conserving rotation of the top layer, with As relaxed outward and Ga inward with a tilt angle {omega}{sub 1} = 28.6 {plus minus} 3{degree}, confirming the results of previous structure analyses for this surface. The quality of the description of the measured intensities, as measured by the x-ray {ital R} factor, is significantly better for LEPD than for low-energy electron diffraction. This result is attributed to the repulsive character of the positron-ion core potential and a resulting more surface sensitive diffraction process for LEPD.

Lessor, D.L. (Pacific Northwest Laboratory, K5-17 ISB-1, Richland, Washington 99352 (United States)); Duke, C.B. (Xerox Webster Research Center, 800 Phillips Road, 0114-38D, Webster, New York 14580 (United States)); Chen, X.M.; Brandes, G.R.; Canter, K.F. (Department of Physics, Brandeis University, Waltham, Massachusetts 02254 (United States)); Ford, W.K. (Advanced Materials Center and Department of Physics, Montana State University, Bozeman, Montana 59717 (United States))

1992-07-01T23:59:59.000Z

125

Slow positron beam techniques for solids and surfaces. Fifth international workshop  

Science Conference Proceedings (OSTI)

These proceedings represent the contributions of leading scientists in the study of solids and surfaces using positron beams as probes. The papers presented at the workshop covered a range of topics including positron beam techniques, positron microscopy, defect depth profiling, Low Energy Positron Diffraction (LEPD), etc. There were sixty nine papers presented at the workshop, out of these, nine have been abstracted for the Energy Science and Technology database. (AIP)

Ottewitte, E. (ed.) (Idaho National Engineering Laboratory (United States)); Weiss, A.H. (ed.) (Physics Department, University of Texas at Arlington, Box 19059, Arlington, TX 76019 (United States))

1994-01-01T23:59:59.000Z

126

Temporal and spatial blood information estimation using Bayesian ICA in dynamic cerebral positron emission tomography  

Science Conference Proceedings (OSTI)

Positron emission tomography (PET) is a nuclear medicine technique that provides tomographic images of the distribution of positron-emitting radiopharmaceuticals. We have previously proposed a method for estimating an input blood curve based on a standard ... Keywords: Arterial blood sampling, Blood volume image, Ensemble learning, Independent component analysis, Positron emission tomography

Mika Naganawa; Yuichi Kimura; Kenji Ishii; Keiichi Oda; Kiichi Ishiwata

2007-09-01T23:59:59.000Z

127

Antimatter as an Energy Source  

SciTech Connect

Antiprotons and positrons are constantly generated in space, and periodically manufactured by humans here on Earth. Harvesting of these particles in space and forming stable antimatter atoms and molecules would create a significant energy source for power and propulsion. Though dedicated fabrication of these particles on Earth consumes much more energy than could be liberated upon annihilation, manufactured antimatter represents a high-density energy storage mechanism well suited for spacecraft power and propulsion. In this paper the creation, storage, and utilization of antimatter is introduced. Specific examples of electrical energy generation and deep-space propulsion based on antimatter are also reviewed.

Jackson, Gerald P. [Hbar Technologies LLC, 1275 W. Roosevelt Road, Suite 130 West Chicago, IL 60185 USA 630-231-7077 (United States)

2009-03-16T23:59:59.000Z

128

Positron annihilation spectroscopy study of materials for reactor vessels  

Science Conference Proceedings (OSTI)

Steels used in the nuclear industry have been experimentally studied by positron annihilation spectroscopy. Analysis of the experimental results and their comparison with the existing data make it possible to reveal vacancy defects, in particular, those caused by neutron radiation, and to determine their size.

Grafutin, V. I.; Prokop'ev, E. P. [Institute for Theoretical and Experimental Physics (Russian Federation); Krsjak, V.; Burcl, R.; Haehner, P.; Zeman, A. [Joint Research Centre of the European Commission, Institute for Energy (Netherlands); Ilyukhina, O. V., E-mail: ilyukhina@itep.ru [Institute for Theoretical and Experimental Physics (Russian Federation); Erak, D. [Russian Research Centre Kurchatov Institute (Russian Federation); Mogilevskyi, M. A.; Myasischeva, G. G.; Funtikov, Yu. V. [Institute for Theoretical and Experimental Physics (Russian Federation)

2011-02-15T23:59:59.000Z

129

ORIGINAL ARTICLE Biodistribution and radiation dosimetry of a positron  

E-Print Network (OSTI)

. Radiation-absorbed doses were estimated by the Medical Internal Radiation Dose scheme. Results After injecting 18 F-SP203, the two organs with highest radiation exposure were urinary bladder wallORIGINAL ARTICLE Biodistribution and radiation dosimetry of a positron emission tomographic ligand

Shen, Jun

130

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

SciTech Connect

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.

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

131

Accelerator Operations and Physics - Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Research Topics Search APS Upgrade* (old) APS-U Technical Meetings* ILC Damping Ring Calculations SR Orbit Drift Characterization* Long Straight Section (for IXS-CAT)* Storage-Ring...

132

Differences between positrons and electrons in elastic and inelastic processes at surfaces  

Science Conference Proceedings (OSTI)

The elastic scattering of positrons of 30 to 300 eV differs significantly from electrons, i.e., a lack of an exchange interaction and ion core repulsion, instead of attraction. Inelastic scattering also differs because there are no final scattering states for the positron which are excluded by the Pauli principle, thus resulting in a shorter positron elastic mean free path. The resulting advantages of LEPD over LEED will be discussed. When a positron is implanted and thermalizes in a solid, many possible fates occur which differs from electrons. The dominant processes for positrons occurring at a metallic surface are (i) localization in a surface state, and (ii) direct reemission from the metal into the vacuum in those systems which exhibit a negative positron work function; during this reemission process the positrons can loose energy by exciting molecular vibrations, (iii) reemission into the vacuum with an electron, thus forming positronium. 47 references.

Canter, K.F.; Lynn, K.G.

1983-09-01T23:59:59.000Z

133

Differences between positrons and electrons in elastic and inelastic processes at surfaces  

Science Conference Proceedings (OSTI)

The elastic scattering of 30--300 eV positrons differs significantly from electrons, i.e., a lack of an exchange interaction and ion core repulsion, instead of attraction. Inelastic scattering also differs because there are no final scattering states for the positron which are excluded by the Pauli principle, thus resulting in a shorter positron elastic mean free path. The resulting advantages of LEPD over LEED will be discussed. When a positron is implanted and thermalizes in a solid, many possible fates occur which differs from electrons. The dominant processes for positrons occurring as a metallic surface are (i) localization in a surface state, (ii) direct reemission from the metal into the vacuum in those systems which exhibit a negative positron work function; during this reemission process the positrons can loose energy by exciting molecular vibrations, and (iii) reemission into the vacuum with an electron, thus forming positronium.

Canter, K.F.; Lynn, K.G.

1984-04-01T23:59:59.000Z

134

Sub-millimeter nuclear medical imaging with reduced dose application in positron emission tomography using beta-gamma coincidences  

E-Print Network (OSTI)

Positron emission tomography (PET) permits a functional understanding of the underlying causes of many diseases. Modern whole-body PET systems reach a spatial resolution of 2-6 mm (FWHM). A limitation of this technique occurs from the thermalization and diffusion of the positron before its annihilation, typically within the mm range. We present a nuclear medical imaging technique, able to reach sub-millimeter spatial resolution in 3 dimensions with a reduced effective dose application compared to conventional PET. This 'gamma-PET' technique draws on specific medical isotopes, simultaneously emitting an additional photon accompanying the beta^+ decay. Exploiting the triple coincidence between the positron annihilation and the third photon, it is possible to separate the reconstructed 'true' events from background. In order to characterize the potential of this technique, MC simulations and image reconstructions have been performed. The achievable spatial resolution has been found to reach ca. 0.4 mm (FWHM) in each direction for the visualization of a 22Na point source. Starting with a source activity of only 1.48 MBq for 89Zr, corresponding to ca. 130 - 270 times less compared to a conventional PET examination using 18F-FDG, about 40 intersections (sufficient for a reliable image reconstruction of a point source) can be identified after a typical examination time of 900 seconds. This results in a strongly reduced effective dose of, e.g., 0.785 mSv for 89Zr-cmAb-U36, compared to the applied effective dose in a typical human PET examination with 18F-FDG of about 7.5 mSv. Increasing the applied effective dose to 7.5 mSv, the examination time will be reduced to 94 s for only 14.2 MBq of 89Zr-cmAb-U36. The reduced effective dose, or, the reduced examination time, surpass the performance of a conventional PET device by more than one order of magnitude.

C. Lang; D. Habs; K. Parodi; P. G. Thirolf

2013-05-18T23:59:59.000Z

135

Low-energy positron and electron diffraction and positron-stimulated secondary electron emission from Cu(100)  

Science Conference Proceedings (OSTI)

The results of two series of experiments are reported. In the first, an electrostatically guided beam of low-energy (40-400 eV) positrons, delta/sub p/ was used to study low-energy positron diffraction (LEPD) from a Cu(100) surface under ultrahigh-vacuum conditions. Low-energy electron diffraction (LEED) data were obtained from the same sample in the same apparatus. Comparison of LEPD and LEED intensity versus energy data with model calculations made using computer programs developed by C.B. Duke and collaborators indicated that: LEPD data is adequately modeled using potentials with no exchange-correlation term. The inelastic mean free path, lambda/sub ee/, is shorter for positrons than for electrons at low (LEPD at making a determination of the first-layer spacing of Cu(100) for the particular data set reported. In the second set of experiments, the same apparatus and sample were used to compare positron- and electron-stimulated secondary-electron emission (PSSEE and ESSEE). The results were found to be consistent with existing models of secondary-electron production for metals. The energy distributions of secondary-electrons had broad low-energy (<10 eV) peaks for both positron and electron stimulation. But the PSEE distribution showed no elastic peak. Measurements of secondary-electron angular distributions, found to be cosine-like in both the PSSEE and ESSEE case, were used to obtain total secondary yield ratios, delta, at four beam energies ranging from 40-400 eV. The secondary yield ratio for primary positrons and the yield for primary electrons, delta/sub e/, were similar at these energies. For 400-eV primary particles the secondary yields were found to be delta/sub p/ = 0.94 +/- 0.12 and delta/sub e/ = 0.94 +/- 0./12, giving a ratio of unity for positron-stimulated secondary yield to electron-stimulated secondary yield.

Weiss, A.H.

1983-01-01T23:59:59.000Z

136

LITHIUM LENS (I)  

E-Print Network (OSTI)

Abstract. Technical/Engineering aspects of Lithium Lens (LL) considered. LL dimensions and parameters adopted for undulator based positron source for International Linear Collider. Sealing technique for windows represented in this publication also. This publication is a part of preparation work for numerical modeling of LL. OVERVIEW Usage of Lithium Lens (LL) for positron collection was suggested years ago [1]-[4]. Lithium lens with solid Lithium is in exploitation for decades now. Usage of LL for antiproton collection is also a well developed topic [5]-[11]. Naturally, usage of LL for positron collection in a scheme with undulator [13], developed in Novosibirsk, included LL from the very beginning [14]-[15]. From the other hand usage of LL for positron collection still not a widely accepted idea, so Novosibirsk lens remains the only one in operation. In resent times we applied some efforts to implement LL into ILC positron source [16]-[21]. Development of positron source for ILC as it is now in baseline design described in [22]. Latest results on practical test undulator-based positron source demonstrated positron polarization ~ 80 % and electron polarization ~90% respectively obtained with Tungsten target [23]. Also interesting looks a possibility for implementation of LL for muon collider [24]-[25]. System with Liquid Lithium is under consideration for Fusion Materials Irradiation studies [26]. Current publication is the first one in series dedicated to demonstration of benefits from potential usage of LL in International Linear Collider. Support for this investigation obtained from ILC GDE Regional Directorship of America.

unknown authors

2009-01-01T23:59:59.000Z

137

Storing Electrons Instead of Positrons Without Trapping of Positive Ions  

NLE Websites -- All DOE Office Websites (Extended Search)

Electrons Instead of Positrons Without Electrons Instead of Positrons Without Trapping of Positive Ions LS-75 T. K. Khoe October, 1986 In this note, a procedure to inject and store electrons in the ring without trapping ions will be described. The minimum injection current per bunch below which ion trapping occur will be determined. Since the vertical beam size is smaller than the horizontal beam size, we will consider the vertical motion only. The following assumptions are made: 1. The bunch period is much longer than the bunch length. This assumption allow us to use the thin lens approximation for the focusing effect of the electron bunch. 2. The bunch length is much larger than the transverse dimensions of the beam. A two-dimensional calculation can then be used to obtain the

138

Clinical cardiac positron emission tomography: State of the art  

SciTech Connect

Cardiac positron emission tomography (PET) has evolved rapidly from a relatively esoteric research tool into clinical applications providing unique, quantitative information on myocardial perfusion, metabolism, and cell membrane function and having a potentially significant impact on cardiovascular medicine. Although there are many different positron radionuclides for imaging diverse myocardial behavior, three radionuclides have reached accepted clinical utility. Cardiac PET using nitrogen-13-ammonia, rubidium-82, and fluoro-18-deoxyglucose has proved accurate and definitive in multiple university and private-practice sites for diagnosing and assessing severity and location of coronary artery disease in symptomatic or asymptomatic patients, for identifying injured but viable myocardium potentially salvageable by revascularization, and for ruling out clinically significant coronary artery stenosis with a high specificity in patients who might otherwise undergo coronary arteriography to document the absence of significant disease. 89 references.

Gould, K.L. (Division of Cardiology, University of Texas Health Science Center, Houston (United States))

1991-09-01T23:59:59.000Z

139

Magnetohydrodynamic spin waves in degenerate electron-positron-ion plasmas  

SciTech Connect

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.

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

140

Positronium formation in positron-hydrogen collisions with Debye potentials  

SciTech Connect

Positronium (Ps) formation cross sections (n = 1, 2) in positron-hydrogen collisions in Debye plasma environment are calculated using the screening approximation model for various Debye screening lengths from the Ps formation thresholds to 50 eV. The effect of the screened Coulomb potential on Ps formation process is investigated by using the Debye-Hueckel potential. The present results are compared with available theoretical calculations.

Ma, J.; Cheng, Y.; Wang, Y. C.; Zhou, Y. [Center for Theoretical Atomic and Molecular Physics, Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150080 (China)

2012-06-15T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Observations of discrete energy loss effects in spectra of positrons reflected from solid surfaces  

Science Conference Proceedings (OSTI)

Surfaces of tungsten and silicon have been bombarded with monoenergetic beams of positrons and electrons. Spectra of reflected particles show energy loss tails with discrete peaks at kinetic energies about 15 eV lower than that of the elastic peaks. In the higher energy loss range for tungsten, positron spectra show fine structure that is not apparent in the electron spectra. This suggests that the positrons are losing energy through mechanisms different from that of the electrons.

Dale, J.M.; Hulett, L.D.; Pendyala, S.

1980-01-01T23:59:59.000Z

142

Effects of Neutron Irradiation on Positron Lifetime and Micro-Vicker ...  

Science Conference Proceedings (OSTI)

Aug 1, 1999 ... Effects of Neutron Irradiation on Positron Lifetime and Micro-Vicker Hardness of Fe-Cu Model Alloys and Reactor Pressure Vessel Steel

143

Microsoft Word - WFnote-238_Summary of short pulse collider.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

electron-positron linear collider from the International Linear Collider (ILC) and Compact Linear Collider (CLIC) teams have been well established. Both proposed machines work...

144

Optical distortions in electron/positron storage rings  

SciTech Connect

We have studied the optical distortions in the PEP electron/positron storage ring for various optical configurations using the computer programs DIMAT, HARMON, PATRICIA, and TURTLE. The results are shown graphically by tracing several thousand trajectories from one interaction region to the next using TURTLE and by tracing a few selected rays several hundred turns using the programs DIMAT and PATRICIA. The results show an interesting correlation between the calculated optical cleanliness of a particular lattice configuration and the observed operating characteristics of the machine.

Brown, K.L.; Donald, M.; Servranckx, R.

1983-01-01T23:59:59.000Z

145

Positron emission tomography in the evaluation of subdural hematomas  

SciTech Connect

Fifteen patients with 21 subdural effusions were investigated both with transmission computer assisted tomography (CAT) and positron emission tomography (PET). The tracer in the emission studies was /sup 68/Ga-EDTA. Twelve lesions were visualized both with CAT and PET. Five lesions that were negative or doubtful on CAT were visualized with PET, whereas four lesions negative or doubtful on PET were demonstrated by CAT. The two methods complement each other due to the fact that they are based on different mechanisms: CAT mainly on attenuation of the fluid collection. PET on isotope accumulation, particularly in the hematoma membranes.

Ericson, K.; Bergstroem, M.; Eriksson, L.

1980-12-01T23:59:59.000Z

146

Low energy positron diffraction from Cu(111): Importance of surface loss processes at large angles of incidence  

Science Conference Proceedings (OSTI)

Intensities of positrons specularly diffracted from Cu(111) were measured at the Brandeis positron beam facility and analyzed in the energy range 8eV40{degree}. 30 refs., 5 figs., 1 tab.

Lessor, D.L. (Pacific Northwest Lab., Richland, WA (USA)); Duke, C.B. (Xerox Corp., Webster, NY (USA). Webster Research Center); Lippel, P.H.; Brandes, G.R.; Canter, K.F.; Horsky, T.N. (Brandeis Univ., Waltham, MA (USA). Dept. of Physics)

1990-10-01T23:59:59.000Z

147

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

SciTech Connect

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.

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

148

Convergent close-coupling calculations of positron-magnesium scattering  

SciTech Connect

The single-center convergent close-coupling method has been applied to positron-magnesium scattering at incident energies from 0.01 to 100 eV. Cross sections are presented for elastic scattering and excitation of 3 {sup 1}P, as well as for the total ionization and total scattering processes. We also provide an estimate of the positronium formation cross section. The results agree very well with the measurements of the total cross section by Stein et al. [Nucl. Instrum. Methods Phys. Res. Sect. B 143, 68 (1998)], and consistent with the positronium formation measurements of Surdutovich et al. [Phys. Rev. A 68, 022709 (2003)] for positron energies above the ionization threshold. For energies below the positronium formation threshold (0.8 eV) we find a large P-wave resonance at 0.17 eV. A similar resonance behavior was found by Mitroy and Bromley [Phys. Rev. Lett. 98, 173001 (2007)] at an energy of 0.1 eV.

Savage, Jeremy S.; Fursa, Dmitry V.; Bray, Igor [ARC Centre for Antimatter-Matter Studies, Curtin University of Technology, GPO Box U1987, Perth, WA 6845 (Australia)

2011-06-15T23:59:59.000Z

149

Sources - CECM  

E-Print Network (OSTI)

help · annotate · Contents Next: References Up: RamanujanModular Equations, Previous: Ramanujan's sum. Sources. [Annotate] · [Shownotes]. References [7] ...

150

Low-energy electron and positron diffraction measurements and analysis on Cu(100)  

Science Conference Proceedings (OSTI)

The results of an experimental study and quantitative analysis of the intensity versus energy (I-V) curves are reported for low-energy electron diffraction and low-energy positron diffraction (LEPD) with a brightness-enhanced electrostatically focused positron beam. In a close comparative study, the incident electrons and positrons scattered at a large incident polar angle (thetagreater than or equal to50/sup 0/) with respect to the surface normal off clean Cu(100) and the I-V spectra from six and seven diffraction beams were taken with electrons and positrons, respectively. The analysis of the experimental data from the electron studies indicates first- and second-layer relaxation that is consistent with earlier results. Use of the structure derived from the electron studies, analysis of the I-V curves from the LEPD studies suggests that the attenuation for positrons is greater than the value for electrons over the energy range 50--400 eV, possibly as a result of the enhanced electron-image cloud surrounding the positron. The real part of the inner potential is 0 eV for positrons compared with 11 eV for electrons, in rough agreement with predictions. Further, the best agreement between experiment and calculation for LEPD I-V curve analysis tends to favor the potential formed by changing of the sign of the Coulomb term (relative to electrons), eliminating the exchange, and retaining the correlation term.

Mayer, R.; Zhang, C.; Lynn, K.G.; Frieze, W.E.; Jona, F.; Marcus, P.M.

1987-03-01T23:59:59.000Z

151

Towards laboratory-produced relativistic electron-positron pair-plasmas  

Science Conference Proceedings (OSTI)

Relativistic pair-plasmas and jets are believed to exist in many astrophysical objects and are often invoked to explain energetic phenomena related to Gamma Ray Bursts and Black Holes. On earth, positrons from radioactive isotopes or accelerators are used extensively at low energies (sub-MeV) in areas related to surface science positron emission tomography and basic antimatter science. Experimental platforms capable of producing the high-temperature pair-plasma and high-flux jets required to simulate astrophysical positron conditions have so far been absent. In the last few years, we performed extensive experiments generating positrons with intense lasers where we found that relativistic electron and positron jets are produced by irradiating a solid gold target with an intense picosecond laser pulse. The positron temperatures in directions parallel and transverse to the beam both exceeded 0.5 MeV, and the density of electrons and positrons in these jets are of order 10{sup 16} cm{sup -3} and 10{sup 13} cm{sup -3}, respectively. With the advent of high-energy ultra-short laser pulses, we expect that a charge-neutral, relativistic pair-plasma is achievable, a novel regime of laboratory-produced hot dense matter. This talk will present some details of the laser-produced pair-plasma experiments.

Chen, H; Wilks, S C; Meyerhofer, D D; Beiersdorfer, P; Cauble, R; Dollar, F; Falk, K; Hazi, A; Murphy, C D; Park, J; Seely, J; Szabo, C I; Shepherd, R; Tommasini, R; Zulick, K

2010-08-31T23:59:59.000Z

152

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

SciTech Connect

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.

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

1995-06-01T23:59:59.000Z

153

Design Considerations for High Energy Electron -- Positron Storage Rings  

DOE R&D Accomplishments (OSTI)

High energy electron-positron storage rings give a way of making a new attack on the most important problems of elementary particle physics. All of us who have worked in the storage ring field designing, building, or using storage rings know this. The importance of that part of storage ring work concerning tests of quantum electrodynamics and mu meson physics is also generally appreciated by the larger physics community. However, I do not think that most of the physicists working tin the elementary particle physics field realize the importance of the contribution that storage ring experiments can make to our understanding of the strongly interacting particles. I would therefore like to spend the next few minutes discussing the sort of things that one can do with storage rings in the strongly interacting particle field.

Richter, B.

1966-11-00T23:59:59.000Z

154

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

SciTech Connect

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.

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

155

Ion source  

DOE Patents (OSTI)

A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

Leung, Ka-Ngo (Hercules, CA); Ehlers, Kenneth W. (Alamo, CA)

1984-01-01T23:59:59.000Z

156

Patient self-attenuation and technologist dose in positron emission tomography  

SciTech Connect

Positron emission tomography (PET), with 511-keV radiation and long patient-uptake times, presents unique radiation safety concerns. This two-part study considers aspects of PET radiation safety as they relate to PET suite design, dose to the public, and technologist occupational dose. In the first part of the study, the self-attenuation of radiation by patients' bodies was quantified. The radiation exposure was measured at three positions from 64 patients injected with fluorine-18 fluorodeoxyglucose (FDG) during the uptake period. Compared with an in vitro control used as a point source, a significant decrease in exposure (>40% at 1 m) was observed due to nonuniform distribution of FDG and attenuation within the patients. The attenuation data are consistent with results from simulations [M. E. Phelps, ''Comments and Perspectives,'' J. Nucl. Med. 45, 1601 (2004)] that treat the body as a uniform, water-filled cylinder. As distance is often the principal source of protection for 511-keV radiation, the considerable self-attenuation may allow for more compact PET suites. However, despite high patient self-attenuation, shielding, and standard precautionary measures, PET technologist occupational doses can remain quite high ({approx}12 mSv/year). The second part of this study tracked the daily dose received by PET technologists. Close technologist-patient interaction both during and following FDG administration, as much as 20 min/study, contribute to the high doses and point to the need for a more innovative approach to radiation protection for PET technologists.

Zeff, Benjamin W.; Yester, Michael V. [Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35233 (United States)

2005-04-01T23:59:59.000Z

157

Comparison of positron tomography and scintigraphy with $sup 201$Tl for delineation of the myocardium  

SciTech Connect

Recent advances in nuclear medicine instrumentation have led to the development of improved positron-imaging systems which exceed in performance the earlier systems which were limited mainly by low count rate capability. This has led to renewed interest in positron imaging in general, primarily because such devices offer better resolution and higher sensitivity than conventional, mechanically collimated gamma cameras, as well as tomographic capability which may provide additional and more accurate information for the clinician. Furthermore, the unique capabilities of positrons for use in reconstructive imaging are beginning to be exploited. In the present report, results are presented from a preliminary study in which longitudinal tomographic myocardial images, produced with $sup 81$Rb as the positron-emitting label using the double camera coincidence system are compared with conventional myocardial images obtained with $sup 201$Tl and a gamma camera. (auth)

Fill, H.; Buchin, M.; Harper, P.V.; Muehllehner, G.; Walsh, W.; Resnekov, L.; Mock, B.

1976-01-01T23:59:59.000Z

158

Hybrid Electron-Positron-Ion Shear Flows and Applications to Gamma-Ray Bursts  

E-Print Network (OSTI)

We present Particle-in-Cell simulation results of relativistic shear boundary layers for hybrid electron-positron-ion plasmas and discuss their potential applications to gamma-ray bursts.

Liang, Edison; Smith, Ian

2013-01-01T23:59:59.000Z

159

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

DOE Patents (OSTI)

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.

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

1993-04-06T23:59:59.000Z

160

Optimization of 2D image reconstruction for positron emission mammography using IDL  

Science Conference Proceedings (OSTI)

The Clear-PEM system is a prototype machine for Positron Emission Mammography (PEM) under development within the Portuguese PET-Mammography consortium. We have embedded 2D image reconstruction algorithms implemented in IDL within the prototype's image ... Keywords: ART, Computer implementation, Emission tomography, FDG, FOM, FOV, FWHM, GEANT, IDL, Image reconstruction, Iterative algorithms, LOR, MLEM, NCAT, NME, OSEM, PEM, PET, PSF, Positron emission mammography, ROI

N. Oliveira; N. Matela; R. Bugalho; N. Ferreira; P. Almeida

2009-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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161

Wave dispersion in a counterstreaming, relativistic thermal, magnetized, electron-positron plasma  

SciTech Connect

The dispersion equation is analyzed for waves in a strongly magnetized, electron-positron plasma in which counterstreaming electrons and positrons have a relativistic thermal distribution in their respective rest frames, for propagation parallel to the magnetic field. We derive the response tensor for the medium, demonstrate the dispersion curves for different temperatures, and discuss the differences from the cold-plasma case. Application to the case of pulsar magnetospheres is discussed.

Verdon, M. W.; Melrose, D. B. [School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia)

2011-05-15T23:59:59.000Z

162

Quench studies of ILC cavities  

SciTech Connect

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.

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

2011-07-01T23:59:59.000Z

163

LHC/ILC/cosmology interplay  

Science Conference Proceedings (OSTI)

[15] LEP Working Group on Higgs Boson Searches: R Barate et al, Phys. Lett. B565, 61. (2003), hep-ex/0306033. [16] A Pilaftsis, Phys. Lett. B435, 88 (1998) ...

164

Electron, Photon, and Positron Scattering Dynamics of Complex Molecular Targets  

E-Print Network (OSTI)

Electron scattering cross sections have been computed for pyridine and pyrimidine using the static-exchange approximation with model potential to account for dynamic electron correlation. To obtain well-converged orbitals, we have expanded all partial waves to a maximum angular momentum of l = 60 for both targets. We have obtained total cross sections for electron scattering energies to 20 eV. Both targets display similar features, namely a dipole-induced increase in the integrated cross section at scattering energies below 5 eV, and peaks corresponding to resonances in b1, a2, and b1 symmetries. These resonances were investigated through a Siegert eigenstate analysis and Breit-Wigner fit of the SECP eigenphase sums. They were also compared to the virtual orbitals obtained from a minimum basis set Hartree-Fock calculation on both targets. We consider electron scattering resonances from cis-diamminedichloroplatinum, [Pt(NH3)2Cl2], the ligand molecular species Cl2 (1Sigma+g ), and the isolated transition metal center Pt in a nondegenerate atomic state (1S) at the SECP level of theory. As a rigorous comparison to the single-state, single-configuration SECP level results of these smaller, yet electron dense targets, we have also considered scattering from ground state Cl2 and Pt in the 1S and 3D states in the multichannel configuration-interaction (MCCI) approximation originally developed for photoionization for scattering up to 10 eV. Photoionization cross sections and angular distributions in the recoil frame (RFPAD) and molecular frame (MFPAD) have been computed for inner-shell C 1s and Cl 2p ionization from the chloroalkanes chloromethane and chloroethane, with ionization leading to a variety of ionic fragment states. We have also computed valence level ionization from the nitro molecule nitromethane CH3NO2 leading to the dissociation of the CN bond. All of these calculations were performed in the frozen-core Hartree-Fock approximation. Even at this level of theory, we obtain computed results that compare well to the photoelectronphotoion coincidence measurements. The fullerene C20 is the smallest fullerene predicted to exist, with most relevant structural calculations suggesting the reduction of the icosahedral symmetry into one in which the target species possesses at maximum only a dihedral axis. We have computed positron scattering cross sections for the molecule in two low-symmetry structural isomers Ci and C2, within the HF approximation. Density functional expressions were used to incorporate important positron-electron interactions within the calculation. We have found similar cross sections and resonance features for both isomers, including a positron scattering resonance whose density is found within the framework of the fullerene cluster.

Carey, Ralph

2012-05-01T23:59:59.000Z

165

Competitive Sourcing  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

COMPETITIVE SOURCING COMPETITIVE SOURCING ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬ Report on Competitive Sourcing Results Fiscal Year 2006 May 2007 Executive Office of the President Office of Management and Budget TABLE OF CONTENTS Executive Summary ...................................................................................... 1 Introduction................................................................................................. 4 I. The big picture ......................................................................................... 4 II. How public-private competition was used in FY 2006 .................................... 6 A. Anticipated benefits from competition in FY 2006

166

NEUTRON SOURCES  

DOE Patents (OSTI)

A neutron source is obtained without employing any separate beryllia receptacle, as was formerly required. The new method is safer and faster, and affords a source with both improved yield and symmetry of neutron emission. A Be container is used to hold and react with Pu. This container has a thin isolating layer that does not obstruct the desired Pu--Be reaction and obviates procedures previously employed to disassemble and remove a beryllia receptacle. (AEC)

Richmond, J.L.; Wells, C.E.

1963-01-15T23:59:59.000Z

167

Novel detector systems for the Positron Emission Tomography  

E-Print Network (OSTI)

In this contribution we describe a novel solution for the construction of Positron Emission Tomograph. We present the device allowing for determination of the impact position as well as time and deph of interaction of the annihilation gamma quanta. The device is comprised of scintillation chamber consisting of organic scintillators surrounding the body of the patient. We discuss two possible solutions: (i) the tomograph built out of scintillator strips, and (ii) the tomograph built out of the scintillator plates. The application of the fast scintillators will enable to take advantage of the difference between time of the registration of the annihilation quanta. The invented method will permit to use a thick layers of detector material with the possibility of measuring the depth of the gamma quantum interaction (DOI) and the determination of their time of flight (TOF), and will allow for increasing the size of the diagnostic chamber without a significant increase of costs. The method is a subject of two patent applications which are based on the techniques used in the particle physics experiments.

P. Moskal; P. Salabura; M. Silarski; J. Smyrski; J. Zdebik; M. Zieli?ski

2013-05-22T23:59:59.000Z

168

Timelike Virtual Compton Scattering from Electron-Positron Radiative Annihilation  

SciTech Connect

We propose measurements of the deeply virtual Compton amplitude (DVCS) {gamma}* {yields} H{bar H}{gamma} in the timelike t = (p{sub H} + p{sub {bar H}}){sup 2} > 0 kinematic domain which is accessible at electron-positron colliders via the radiative annihilation process e{sup +}e{sup -} {yields} H{bar H}{gamma}. These processes allow the measurement of timelike deeply virtual Compton scattering for a variety of H{bar H} hadron pairs such as {pi}{sup +}{pi}{sup -}, K{sup +}K{sup -}, and D{bar D} as well as p{bar p}. As in the conventional spacelike DVCS, there are interfering coherent amplitudes contributing to the timelike processes involving C = - form factors. The interference between the amplitudes measures the phase of the C = + timelike DVCS amplitude relative to the phase of the timelike form factors and can be isolated by considering the forward-backward e{sup +} {leftrightarrow} e{sup -} asymmetry. The J = 0 fixed pole contribution which arises from the local coupling of the two photons to the quark current plays a special role. As an example we present a simple model.

Afanasev, Andrei; /Hampton U. /Jefferson Lab; Brodsky, Stanley J.; /SLAC; Carlson, Carl E.; /William-Mary Coll.; Mukherjee, Asmita; /Indian Inst. Tech., Mumbai

2009-03-31T23:59:59.000Z

169

Positron Emission Tomography Detector Development for Plant Biology  

Science Conference Proceedings (OSTI)

There are opportunities for the development of new tools to advance plant biology research through the use of radionuclides. Thomas Jefferson National Accelerator Facility, Duke University, West Virginia University and the University of Maryland are collaborating on the development of radionuclide imaging technologies to facilitate plant biology research. Biological research into optimizing plant productivity under various environmental constraints, biofuel and carbon sequestration research are areas that could potentially benefit from new imaging technologies. Using 11CO2 tracers, the investigators at Triangle University Nuclear Laboratory / Duke University Phytotron are currently researching the dynamical responses of plants to environmental changes forecasted from increasing greenhouse trace gases involved in global change. The biological research primary focus is to investigate the impact of elevated atmospheric CO2 and nutrients limitation on carbon and nitrogen dynamics in plants. We report here on preliminary results of 11CO2 plant imaging experiments involving barley plants using Jefferson Lab dual planar positron emission tomography detectors to image 11CO2 in live barley plants. New detector designs will be developed based on the preliminary studies reported here and further planned.

Weisenberger, A G; McKisson, J; Stolin, A; Zorn, C; Howell, C R; Crowell, A S; Reid, C D; Majewski, S

2010-01-01T23:59:59.000Z

170

A Moment-Preserving Single-Event Monte Carlo Model of Electron and Positron Energy-Loss Straggling.  

E-Print Network (OSTI)

??Analog simulation of energy straggling of electrons and positrons is computationally impractical because of long-range Coulomb forces resulting in highly peaked cross sections about small… (more)

Gonzales, Matthew

2013-01-01T23:59:59.000Z

171

Competitive Sourcing  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Competitive Sourcing Competitive Sourcing The Department of Energy's (DOE) Competitive Sourcing program is a management initiative aimed at improving DOE's performance and reducing the Department's operational costs. The program is governed by Office of Management and Budget (OMB) Circular A- 76, Performance of Commercial Activities, dated May 29, 2003. The commercial activities selected for review and competition include functions performed by government employees that are readily available in the private sector, and where the potential for efficiencies, regardless of the winning provider, are highly likely. The candidate functions are chosen from the Department's annual Federal Activities Inventory Reform (FAIR) Act Inventory and subjected to a feasibility review to determine if a prudent business case can be made to enter

172

Neutron source  

DOE Patents (OSTI)

A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap.

Cason, J.L. Jr.; Shaw, C.B.

1975-10-21T23:59:59.000Z

173

ION SOURCE  

DOE Patents (OSTI)

The ion source described essentially eliminater the problem of deposits of nonconducting materials forming on parts of the ion source by certain corrosive gases. This problem is met by removing both filament and trap from the ion chamber, spacing them apart and outside the chamber end walls, placing a focusing cylinder about the filament tip to form a thin collimated electron stream, aligning the cylinder, slits in the walls, and trap so that the electron stream does not bombard any part in the source, and heating the trap, which is bombarded by electrons, to a temperature hotter than that in the ion chamber, so that the tendency to build up a deposit caused by electron bombardment is offset by the extra heating supplied only to the trap.

Leland, W.T.

1960-01-01T23:59:59.000Z

174

RADIATION SOURCES  

DOE Patents (OSTI)

A novel long-lived source of gamma radiation especially suitable for calibration purposes is described. The source of gamma radiation is denoted mock iodine131, which comprises a naixture of barium-133 and cesium-137. The barium and cesium are present in a barium-cesium ratio of approximately 5.7/1 to 14/1, uniformly dispersed in an ion exchange resin and a filter surrounding the resin comprised of a material of atomic number below approximately 51, and substantially 0.7 to 0.9 millimeter thick.

Brucer, M.H.

1958-04-15T23:59:59.000Z

175

NEUTRON SOURCE  

DOE Patents (OSTI)

A neutron source of the antimony--beryllium type is presented. The source is comprised of a solid mass of beryllium having a cylindrical recess extending therein and a cylinder containing antimony-124 slidably disposed within the cylindrical recess. The antimony cylinder is encased in aluminum. A berylliunn plug is removably inserted in the open end of the cylindrical recess to completely enclose the antimony cylinder in bsryllium. The plug and antimony cylinder are each provided with a stud on their upper ends to facilitate handling remotely.

Reardon, W.A.; Lennox, D.H.; Nobles, R.G.

1959-01-13T23:59:59.000Z

176

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

NLE Websites -- All DOE Office Websites (Extended Search)

Injector For The ANL 7 Ge V Injector For The ANL 7 Ge V Advanced Photon Source A. Nassiri, W. Wesolowski, and G. Mavrogenes Argonne National Laboratory Submitted to the 1990 LINAC Conferece Albuquerque, New Mexico LS-154 9/28/90 TEE LINAC INJECTOR FOR TEE ANL 7 G<.iJ,V ADVANCED PHOTON SOORCE* A. Nassiri, W. Wesolowski, and G. Mavrogenes Argonne National Laboratory 9700 South Cass Avenue Argonne, IL 60439 USA Abstract The Argonne Advanced Photon Source (APS) linac system consists of a 200 MeV electron linac, a positron converter, and a 450 MeV positron linac. Design parameters and computer simulations of the two linac systems are presented. Introduction The Argonne Advanced Photon Source is a 7 GeV synchrotron X-Ray facility. The APS machine parameters have been described.

177

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

E-Print Network (OSTI)

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.

Kunihito Ioka

2008-12-30T23:59:59.000Z

178

COMPETITIVE SOURCING  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

COMPETITIVE SOURCING COMPETITIVE SOURCING EXECUTIVE STEERING GROUP MEETING PROCEEDINGS June 17, 2002 8:30 am - 11:00 am Room 5E-069 ATTENDEES John Gordon Robert Card Bruce Carnes Kathy Peery Brendan Danaher, AFGE Tony Lane Karen Evans Bill Sylvester Claudia Cross Brian Costlow Laurie Smith Helen Sherman Frank Bessera Rosalie Jordan Dennis O'Brien Mark Hively Robin Mudd Steven Apicella AGENDA 8:30 a.m. - 8:35 a.m. Opening Remarks 8:35a.m. - 8:55 a.m. Executive Steering Group roles and responsibilities, A-76 status, and talking points Team Briefings 8:55 a.m. - 9:20 a.m. Information Technology Study 9:20 a.m. - 9:45 a.m. Financial Services Study

179

ION SOURCE  

DOE Patents (OSTI)

An ion source is described and comprises an arc discharge parallel to the direction of and inside of a magnetic field. an accelerating electrode surrounding substantially all of the discharge except for ion exit apertures, and means for establishing an electric field between that electrode and the arc discharge. the electric field being oriented at an acute angle to the magnetic field. Ions are drawn through the exit apertures in the accelrating electrcde in a direction substantially divergent to the direction of the magnetic field and so will travel in a spiral orbit along the magnetic field such that the ions will not strike the source at any point in their orbit within the magnetic field.

Blue, C.W.; Luce, J.S.

1960-07-19T23:59:59.000Z

180

New Measurement of the Cosmic-Ray Positron Fraction from 5 to 15 GeV  

E-Print Network (OSTI)

We present a new measurement of the cosmic-ray positron fraction at energies between 5 and 15 GeV with the balloon-borne HEAT-pbar instrument in the spring of 2000. The data presented here are compatible with our previous measurements, obtained with a different instrument. The combined data from the three HEAT flights indicate a small positron flux of non-standard origin above 5 GeV. We compare the new measurement with earlier data obtained with the HEAT-e+- instrument, during the opposite epoch of the solar cycle, and conclude that our measurements do not support predictions of charge sign dependent solar modulation of the positron abundance at 5 GeV.

J. J. Beatty; A. Bhattacharyya; C. Bower; S. Coutu; M. A. DuVernois; S. McKee; S. A. Minnick; D. Muller; J. Musser; S. Nutter; A. W. Labrador; M. Schubnell; S. Swordy; G. Tarle; A. Tomasch

2004-12-09T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

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

SciTech Connect

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.

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

182

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

SciTech Connect

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.

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

183

Application of exterior complex scaling to positron-hydrogencollisions including rearrangement  

SciTech Connect

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.

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

2007-12-06T23:59:59.000Z

184

Acoustic double layer structures in dense magnetized electron-positron-ion plasmas  

SciTech Connect

The acoustic double layer structures are studied using quantum hydrodynamic model in dense magnetized electron-positron-ion plasmas. The extended Korteweg-de Vries is derived using reductive perturbation method. It is found that increase in the ion concentration in dense magnetized electron-positron plasmas increases the amplitude as well as the steepness of the double layer structure. However, increase in the magnetic field strength and decrease in the obliqueness of the nonlinear acoustic wave enhances only the steepness of the double layer structures. The numerical results have also been shown by using the data of the outer layer regions of white dwarfs given in the literature.

Akhtar, N.; 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)

2011-11-15T23:59:59.000Z

185

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

E-Print Network (OSTI)

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.

Grafutin, V I; Elnikova, L V

2012-01-01T23:59:59.000Z

186

Ion acoustic solitary waves and double layers in dense electron-positron-ion magnetoplasma  

Science Conference Proceedings (OSTI)

The existence of ion acoustic solitary waves is studied in a magnetized dense electron-positron-ion plasma. The ions are described by the hydrodynamic equations, and the electron and positron are assumed to follow the Thomas-Fermi density distribution. The pseudopotential is derived directly from the basic equations including Poisson's equation without assuming the quasineutrality condition. The effect of ion temperature on the solitary waves is studied, and the ranges of parameters for which solitary waves and double layers exist are also studied in detail using Sagdeev's technique.

Chatterjee, Prasanta [Department of Physics, Plasma Research Laboratory, University of Malaya, 50603 Kuala Lumpur (Malaysia); Department of Mathematics, Siksha Bhavana Visva Bharati University, Santiniketan-731235 (India); Saha, Taraknath [Department of Mathematics, Siksha Bhavana Visva Bharati University, Santiniketan-731235 (India); Muniandy, S. V.; Wong, C. S. [Department of Physics, Plasma Research Laboratory, University of Malaya, 50603 Kuala Lumpur (Malaysia); Roychoudhury, Rajkumar [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata-700108 (India)

2010-01-15T23:59:59.000Z

187

SHIELDING ESTIMATES FOR THE ANL 6.0 GeV SYNCHROTRON LIGHT SOURCE  

NLE Websites -- All DOE Office Websites (Extended Search)

SHIELDING ESTIMATES FOR THE ANL 6.0 GeV SHIELDING ESTIMATES FOR THE ANL 6.0 GeV SYNCHROTRON LIGHT SOURCE H. J. Moe V. R. Veluri LS-55-Revised Harch 1987 2 1.0 Introduction Shielding estimates for the linac, positron converter, booster synchrotron and the positron storage ring have been computed using preliminary design information. Calculations have been made of the resulting radiation for several types of operations involving normal beam loss, as well as, certain accidental beam losses. When available, experimental data from existing accelerator and light source facilities have been used in lieu of theoretical estimates. 2.0 Shielding Design Objective The Department of Energy's basic occupational exposure limit is 5 rem per year (DOE 81). However, in its guidance for maintaining exposures "as

188

COMPETITIVE SOURCING  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

EXECUTIVE STEERING GROUP Meeting Proceedings October 30, 2002 Room 6E-069, 10:30 - 12:00 Agenda Opening Remarks Bruce Carnes Competitive Sourcing Update Denny O'Brien Team Briefings Team Leads ESG Discussion/Wrap up Bruce Carnes Attendees Bruce Carnes, Acting Chair MaryAnn Shebek Robert Card Prentis Cook Ambassador Brooks Tony Lane Kyle McSlarrow Karen Evans Suzanne Brennan, NTEU Claudia Cross Brian Costlow Helen Sherman Frank Bessera Laurie Morman Denny O'Brien Travis McCrory Bill Pearce Jeff Dowl Mark Hively Steven Apicella Robin Mudd Bruce Carnes chaired the meeting and began with welcoming NTEU to the meeting. In regard to the OMB's Balanced Scorecard, the Department has achieved a Green on progress and we are close to achieving a yellow on status.

189

Gamma-ray spectra of methane in the positron-electron annihilation process  

E-Print Network (OSTI)

Bound electron contribution to the Doppler-shift of gamma-ray spectra in the positron-electron annihilation process of molecular methane has been studied in gas phase. Two accurate ab initio quantum mechanical schemes, i.e. the delocalized molecular orbital (MO) and the localized natural bond orbital (NBO) schemes, are applied to study the multi-centred methane molecule. The present ab initio calculations of methane indicate that the C-H bonds are polarized with the partial negative charge of -0.36 a.u. on the carbon atom and the partial positive charge of +0.09 a.u. on each of the hydrogen atoms. The positively charged hydrogen atoms produce repulsive Coulomb potentials to a positron. Both the MO and NBO schemes further reveal that the 2a1 electrons of methane, that is, the 2a1 electron component of the C-H bonds rather than the whole C-H bonds of methane, predominates the positron-electron annihilation gamma-ray spectra of the molecule. Electrons of a molecule which are dominant the positron-electron annihilation processes are called positrophilic electrons in the present study. It is further shown that the negative electrostatic potential (ESP) of methane facilitates with the density of the positrophilic 2a1 electrons of methane. Other valence electrons (e.g. 1t2) in the C-H bonds play a minor spectator role in the annihilation process of methane.

Xiaoguang Ma; Feng Wang

2012-11-02T23:59:59.000Z

190

Measurements of the Cosmic-Ray Positron Fraction From 1 to 50 GeV  

E-Print Network (OSTI)

Two measurements of the cosmic-ray positron fraction as a function of energy have been made using the High Energy Antimatter Telescope (HEAT) balloon-borne instrument. The first flight took place from Ft. Sumner, New Mexico in 1994, and yielded results above the geomagnetic cutoff energy of 4.5 GeV. The second flight from Lynn Lake, Manitoba in 1995 permitted measurements over a larger energy interval, from 1 GeV to 50 GeV. In this letter we present results on the positron fraction based on data from the Lynn Lake flight, and compare these with the previously published results from the Ft. Sumner flight. The results confirm that the positron fraction does not increase with energy above ~10 GeV, although a small excess above purely secondary production cannot be ruled out. At low energies the positron fraction is slightly larger than that reported from measurements made in the 1960's. This effect could possibly be a consequence of charge dependence in the level of solar modulation.

HEAT Collaboration; S. W. Barwick; E. Schneider; J. J. Beatty; G. A. de Nolfo; A. Bhattacharyya; C. R. Bower; J. A. Musser; C. J. Chaput; S. Coutu; S. McKee; G. Tarle; A. D. Tomasch; J. Knapp; D. M. Lowder; D. Muller; S. P. Swordy; E. Torbet; S. L. Nutter

1997-03-28T23:59:59.000Z

191

Low energy electron and positron diffraction from surfaces. What you learn. How they differ  

Science Conference Proceedings (OSTI)

An overview of similarities and differences between low-energy (30 Ev to 250 Ev) electron and positron diffraction as probes of material surfaces is given. LEPD may offer greater surface sensitivity, and also better spatial resolution for polyatomic materials. (AIP)

Lessor, D.L. (Pacific Northwest Laboratory, Richland, Washington 99352 (United States)); Canter, K.F. (Brandeis University, Waltham, Massachusetts 02254 (United States)); Duke, C.B. (Xerox Webster Research Center, Webster, New York 14580 (United States))

1994-06-15T23:59:59.000Z

192

Measurements of the Cosmic-Ray Positron Fraction From 1 to 50 GeV  

E-Print Network (OSTI)

Two measurements of the cosmic-ray positron fraction as a function of energy have been made using the High Energy Antimatter Telescope (HEAT) balloon-borne instrument. The first flight took place from Ft. Sumner, New Mexico in 1994, and yielded results above the geomagnetic cutoff energy of 4.5 GeV. The second flight from Lynn Lake, Manitoba in 1995 permitted measurements over a larger energy interval, from 1 GeV to 50 GeV. In this letter we present results on the positron fraction based on data from the Lynn Lake flight, and compare these with the previously published results from the Ft. Sumner flight. The results confirm that the positron fraction does not increase with energy above ~10 GeV, although a small excess above purely secondary production cannot be ruled out. At low energies the positron fraction is slightly larger than that reported from measurements made in the 1960's. This effect could possibly be a consequence of charge dependence in the level of solar modulation.

Barwick, S W; Beatty, J J; De Nolfo, G A; Bhattacharya, A; Bower, C; Musser, J A; Chaput, C J; Coutu, S; McKee, S; Tarlé, G; Tomasch, A D; Knapp, J; Lowder, D M; Müller, D; Swordy, S P; Torbet, E; Nutter, S L

1997-01-01T23:59:59.000Z

193

Radiation source  

DOE Patents (OSTI)

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.

Thode, Lester E. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

194

The SPRITE and POS-SPRITE user report: An extensible calculation of particle, positron and electron implantation in solids  

Science Conference Proceedings (OSTI)

SPRITE (Simulation of Particle Reemission, Implantation and Transmission--Extensible) is a Fortran computer program designed to model the transport of a stream of energetic particles as they scatter through a solid or multilayer. SPRITE is intended to be a user-friendly and easily-extensible engine for performing basic transport calculations, and SPRITE incorporates such physics as is required to simulate the transport process, but specifically omits the details of the scattering mechanisms. PSPRITE is a Fortran computer program, built around the SPRITE transport engine and incorporating physical information necessary for modeling the implantation and thermalization of a stream of positrons or electrons with a solid. This document is intended to be the primary source of information and the only operations manual for SPRITE and the POS-SPRITE family of programs. This information includes the mode of operation of SPRITE, the format of the required and optional file types, as well as information about the output and results of the calculation. Information about installing and running these programs on a variety of computer systems will not be addressed in this report. Such information is rapidly expanding as these programs are adapted to run on different platforms, and thus the user can expect such information to be contained with the source code distribution set. Detailed information about the calculations of the structure of the POS-SPRITE programs are provided in this report, but detailed benchmark comparisons between the output of these calculations and experimental data are an active topic of research, and they refer the reader to the published literature for this information.

Ritley, K.A. [Univ. of Illinois, Urbana, IL (United States); Ghosh, V.J.; Lynn, K.G.; McKewown, M.; Welch, D.O. [Brookhaven National Lab., Upton, NY (United States)

1997-10-20T23:59:59.000Z

195

Source Selection | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Source Selection Source Selection Source SelectionSource Selection Boards Source Evaluation Board (SEB) Monthly Status Reporting Requirement (pdf) Source Evaluation Board (SEB)...

196

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

SciTech Connect

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.

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

197

Bound-Free Electron-Positron Pair Production in Relativistic Heavy-Ion Collisions  

E-Print Network (OSTI)

The bound-free electron-positron pair production is considered for relativistic heavy ion collisions. In particular, cross sections are calculated for the pair production with the simultaneous capture of the electron into the 1s ground state of one of the ions and for energies that are relevant for the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Colliders (LHC). In the framework of perturbation theory, we applied Monte-Carlo integration techniques to compute the lowest-order Feynman diagrams amplitudes by using Darwin wave functions for the bound states of the elec- trons and Sommerfeld-Maue wave functions for the continuum states of the positrons. Calculations were performed especially for the collision of Au + Au at 100 GeV/nucleon and Pb + Pb at 3400 GeV/nucleon.

M. Y. Sengul; M. C. Guclu; S. Fritzsche

2009-07-30T23:59:59.000Z

198

Nonlinear screening effect in an ultrarelativistic degenerate electron-positron gas  

SciTech Connect

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.

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

199

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

SciTech Connect

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.

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

200

Assay of weathering effects on protective polymer coatings using positron annihilation spectroscopy  

Science Conference Proceedings (OSTI)

Polymer coatings, both with and without pigments, have been subjected to solar radiation and water spray weathering. The degrees of penetration of the weathering effects have been measured by injecting positrons of varying energy, i.e. to variable depths, into the films and observing the Doppler broadening of the annihilation radiation. The method is capable of detecting changes due to weathering effects at very early stages, long before visual examination reveals degradation. As little as one week of exposure caused measurable changes in the polymer structure, which were reflected in the Doppler broadening. Given further development, positron spectroscopy could possibly become a useful complement to the other methods of determining weatherabilities of protective polymer coatings.

Hulett, L.D. Jr.; Wallace, S.; Xu, Jun [Oak Ridge National Lab., TN (United States); Nielsen, B.; Szeles, Cs.; Lynn, K.G. [Brookhaven National Lab., Upton, NY (United States); Pfau, J.; Schaub, A.

1995-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Positron emission imaging device and method of using the same  

DOE Patents (OSTI)

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.

Bingham, Philip R.; Mullens, James Allen

2013-01-15T23:59:59.000Z

202

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

SciTech Connect

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.

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

203

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

E-Print Network (OSTI)

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)\

Kleinert, Hagen; Xue, She-Sheng

2008-01-01T23:59:59.000Z

204

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

E-Print Network (OSTI)

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)\

Hagen Kleinert; Remo Ruffini; She-Sheng Xue

2008-07-06T23:59:59.000Z

205

Dynamic Positron Emission Tomography [PET] in Man Using Small Bismuth Germanate Crystals  

DOE R&D Accomplishments (OSTI)

Primary considerations for the design of positron emission tomographs for medical studies in humans are the need for high imaging sensitivity, whole organ coverage, good spatial resolution, high maximum data rates, adequate spatial sampling with minimum mechanical motion, shielding against out of plane activity, pulse height discrimination against scattered photons, and timing discrimination against accidental coincidences. We discuss the choice of detectors, sampling motion, shielding, and electronics to meet these objectives.

Derenzo, S. E.; Budinger, T. F.; Huesman, R. H.; Cahoon, J. L.

1982-04-00T23:59:59.000Z

206

Diagnostic merits of current and potential applications of single photon and positron imaging: a perspective  

SciTech Connect

A brief review of the limitations of medical radionuclide imaging techniques in competition with x-ray CAT scanning and ultrasound suggest that the emphasis in this are should be on measurement of the physiologic uptake of tracer materials. Tomography greatly improves the possibilities of quantitation of this uptake - examples using positron and single photon techniques are presented for /sup 13/NH/sub 3/ and /sup 201/Tl in the heart.

Harper, P.V.

1978-01-01T23:59:59.000Z

207

Imaging atherosclerotic plaque inflammation with [18F]- fluorodeoxyglucose positron emission tomography  

E-Print Network (OSTI)

of tracer CI Confidence interval CO2 Carbon dioxide CRP C-reactive protein CT Computed tomography DPM Decays per minute eNOS Endothelial nitric oxide synthase EDTA Ethylene diamine tetra-acetic acid ETL Echo train... rabbit p Probability PBMC Peripheral blood mononuclear cells PBS Phosphate-buffered saline PDGF Platelet-derived growth factor PDW Proton density-weighted PET Positron emission tomography PK11195 1-(2-chlorophenyl...

Rudd, James H. F.

2003-10-07T23:59:59.000Z

208

Electron Positron Proton Spectrometer for use at Laboratory for Laser Energetics  

Science Conference Proceedings (OSTI)

The Electron Positron Proton Spectrometer (EPPS) is mounted in a TIM (Ten-Inch Manipulator) system on the Omega-60 or Omega-EP laser facilities at the University of Rochester, Laboratory for Laser Energetics (LLE), when in use, see Fig. 1. The Spectrometer assembly, shown in Fig. 2, is constructed of a steel box containing magnets, surrounded by Lead 6% Antimony shielding with SS threaded insert, sitting on an Aluminum 6061-T6 plate.

Ayers, S L

2010-04-07T23:59:59.000Z

209

Community petascale project for accelerator science and simulation: Advancing computational science for future accelerators and accelerator technologies  

E-Print Network (OSTI)

spallation neutron sources (SNS, LANSCE) and its synchrotronII, LHC, RHIC, NLC, ILC design, SNS, and LCLS [8]. They wereILC damping ring modeling, SNS, RIKEN cyclotron injector,

Spentzouris, Panagiotis

2008-01-01T23:59:59.000Z

210

Continuum gamma-ray emission from light dark matter positrons and electrons  

E-Print Network (OSTI)

The annihilation of light dark matter was recently advocated as a possible explanation of the large positron injection rate at the Galactic center deduced from observations by the SPI spectrometer aboard INTEGRAL. The modelling of internal Bremsstrahlung and in-flight annihilation radiations associated to this process drastically reduced the mass range of this light dark matter particle. We estimate critically the various energy losses and radiations involved in the propagation of the positron before its annihilation --in- flight or at rest. Using a simple model with mono-energetic positrons injected and confined to the Galactic bulge, we compute energy losses and gamma-ray radiations caused by ionization, Bremsstrahlung interactions as well as in-flight and at rest annihilation and compare these predictions to the available observations, for various injection energies. Confronting the predictions with observations by the CGRO/EGRET, CGRO/COMPTEL, INTEGRAL/SPI and INTEGRAL/IBIS/ISGRI instruments, we deduce a mass upper bound of 3 to 7.5 MeV/c^2 for the hypothetical light dark matter particle. The most restrictive limit is in agreement with the value previously found by Beacom and Yuksel and was obtained under similar assumptions, while the 7.5 MeV/c^2 value corresponds to more conservative choices and to a partially ionized propagation medium. We stress how the limit depends on the degree of ionization of the propagation medium and how its precision could be improved by a better appraisal of data uncertainties.

P. Sizun; M. Casse; S. Schanne

2006-07-17T23:59:59.000Z

211

Coulomb Distortion Effects for Electron or Positron Induced $(e,e')$ Reactions in the Quasielastic Region  

E-Print Network (OSTI)

In response to recent experimental studies we investigate Coulomb distortion effects on $(e,e')$ reactions from medium and heavy nuclei for the case of electrons and positrons. We extend our previously reported full DWBA treatment of Coulomb distortions to the case of positrons for the $^{208}Pb(e,e')$ reaction in the quasielastic region for a particular nuclear model. In addition, we use previously reported successful approaches to treating Coulomb corrections in an approximate way to calculate the Coulomb distortion effects for $(e,e')$ reactions for both electrons and positrons for the case of a simple nuclear model for quasielastic knock-out of nucleons. With these results in hand we develop a simple {\\em ad-hoc} approximation for use in analyzing experiments, and discuss methods of extracting the ``longitudinal structure function" which enters into evaluation of the Coulomb sum rule. These techniques are generally valid for lepton induced reactions on nuclei with momentum transfers greater than approximately 300 $MeV/c$.

K. S. Kim; L. E. Wright; D. A. Resler

2001-03-13T23:59:59.000Z

212

Cerebral imaging using $sup 68$Ga DTPA and the U.C.S.F. multiwire proportional chamber positron camera  

SciTech Connect

A multiwire proportional chamber positron camera consisting of four 48 x 48 cm$sup 2$ detectors linked to a small digital computer has been designed, constructed, and characterized. Initial clinical application to brain imaging using $sup 68$Ga DTPA in 10 patients with brain tumors is described. Tomographic image reconstruction is accomplished by an algorithm determining the intersection of the annihilation photon paths in planes of interest. Final image processing utilizes uniformity correction, simple thresholding, and smoothing. The positron brain images were compared to conventional scintillation brain scans and x-ray computerized axial tomograms (CAT) in each case. The positron studies have shown significant mitigation of confusing superficial activity resulting from craniotomy in comparison to conventional brain scans. Central necrosis of lesions observed in the positron images, but not in the conventional scans, has been confirmed in CAT. Modifications of the camera are being implemented to improve image quality, and these changes combined with the tomography inherent in the positron scans are anticipated to result in images superior in information content to conventional brain scans. (auth)

Hattner, R.S.; Lim, C.B.; Swann, S.J.; Kaufman, L.; Perez-Mendez, V.; Chu, D.; Huberty, J.P.; Price, D.C.; Wilson, C.B.

1975-12-01T23:59:59.000Z

213

Electrolytes for power sources  

DOE Patents (OSTI)

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

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

1995-01-01T23:59:59.000Z

214

Electrolytes for power sources  

DOE Patents (OSTI)

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.

Doddapaneni, N.; Ingersoll, D.

1995-01-03T23:59:59.000Z

215

Calibrated Neutron Sources  

Science Conference Proceedings (OSTI)

... NIST designed a compliant source. ... needed for new purposes and as old sources decay ... The figure shows a reprentative energy spectrum from such ...

2013-07-30T23:59:59.000Z

216

Electron-Positron Pair Production in Structured Pulses of Electric Fields  

E-Print Network (OSTI)

The non-perturbative electron-positron pair production in time-dependent electric fields is investigated. The quantum kinetic formalism is employed in order to calculate the electron density for various field configurations. The corresponding set of first order, ordinary differential equations is analyzed and numerically solved. The focus of this study lies on the dynamically assisted Schwinger effect in pulsed electric fields with at least two different time scales. Furthermore, interference effects arising in setups with multiple pulses are examined and first results for an optimization of the particle number yield by pulse-shaping are given.

Christian Kohlfürst

2012-12-04T23:59:59.000Z

217

Comoving acceleration of overdense electron-positron plasma by colliding ultra-intense laser pulses  

Science Conference Proceedings (OSTI)

Particle-in-cell (PIC) simulation results of sustained acceleration of electron-positron (e+e-) plasmas by comoving electromagnetic (EM) pulses are presented. When a thin slab of overdense e+e- plasma is irradiated with linear-polarized ultra-intense short laser pulses from both sides, the pulses are transmitted when the plasma is compressed to thinner than {approx}2 relativistic skin depths. A fraction of the plasma is then captured and efficiently accelerated by self-induced JxB forces. For 1 {mu}m laser and 10{sup 21} W cm{sup -2} intensity, the maximum energy exceeds GeV in a picosecond.

Liang, Edison [Rice University, P.O. Box 1892, Houston, Texas 77251 (United States)

2006-06-15T23:59:59.000Z

218

Dipolar vortices and collisional instability in rotating electron-positron-ion plasmas  

SciTech Connect

Linear dispersion relation of electrostatic waves is derived for rotating electron-positron-ion (e-p-i) plasmas. The role of the rotational plasma frequency on drift wave through Coriolis force in the pulsar magnetosphere is discussed. This wave can couple with acoustic mode. In the nonlinear regime, stationary solution in the form of dipolar vortices is obtained. At the end we have also found the collisional instability in the presence of neutral-ion collisions for this rotating e-p-i plasma. The importance of the study with respect to astrophysical plasmas is also pointed out.

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

2011-11-15T23:59:59.000Z

219

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

SciTech Connect

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.

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

220

Photo-degradation of Lexan polycarbonate studied using positron lifetime spectroscopy  

SciTech Connect

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.

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

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Sub-millimeter nuclear medical imaging with reduced dose application in positron emission tomography using beta-gamma coincidences  

E-Print Network (OSTI)

Positron emission tomography (PET) permits a functional understanding of the underlying causes of many diseases. Modern whole-body PET systems reach a spatial resolution of 2-6 mm (FWHM). A limitation of this technique occurs from the thermalization and diffusion of the positron before its annihilation, typically within the mm range. We present a nuclear medical imaging technique, able to reach sub-millimeter spatial resolution in 3 dimensions with a reduced effective dose application compared to conventional PET. This 'gamma-PET' technique draws on specific medical isotopes, simultaneously emitting an additional photon accompanying the beta^+ decay. Exploiting the triple coincidence between the positron annihilation and the third photon, it is possible to separate the reconstructed 'true' events from background. In order to characterize the potential of this technique, MC simulations and image reconstructions have been performed. The achievable spatial resolution has been found to reach ca. 0.4 mm (FWHM) in ...

Lang, C; Parodi, K; Thirolf, P G

2013-01-01T23:59:59.000Z

222

Source Selection Guide | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Source Selection Guide Source Selection Guide Source Selection Guide More Documents & Publications Source Selection Guide Source Selection Guide Source Selection...

223

September 2004  

NLE Websites -- All DOE Office Websites (Extended Search)

4 4 SLAC-TN-04-04 September 2004 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the ILC Conventional Positron Source: Long Drive Pulse Option V. Bharadwaj, Y. Batygin, D.C. Schultz, J.C. Sheppard

224

Generation of zonal flows by electrostatic drift waves in electron-positron-ion plasmas  

Science Conference Proceedings (OSTI)

Generation of large-scale zonal flows by comparatively small-scale electrostatic drift waves in electron-positron-ion plasmas is considered. The generation mechanism is based on the parametric excitation of convective cells by finite amplitude drift waves having arbitrary wavelengths (as compared with the ion Larmor radius of plasma ions at the plasma electron temperature). Temperature inhomogeneity of electrons and positrons is taken into account assuming ions to be cold. To describe the generation of zonal flow generalized Hasegawa-Mima equation containing both vector and two scalar (of different nature) nonlinearities is used. A set of coupled equations describing the nonlinear interaction of drift waves and zonal flows is deduced. Explicit expressions for the maximum growth rate as well as for the optimal spatial dimensions of the zonal flows are obtained. Enriched possibilities of zonal flow generation with different growth rates are revealed. The present theory can be used for interpretations of drift wave observations in laboratory and astrophysical plasmas.

Kaladze, T. D. [Department of Physics, Government College University, 54000 Lahore (Pakistan); I. Vekua Institute of Applied Mathematics, Tbilisi State University, 2 University Str., 0186 Tbilisi (Georgia); Shad, M. [Department of Physics, Government College University, 54000 Lahore (Pakistan); Tsamalashvili, L. V. [I. Vekua Institute of Applied Mathematics, Tbilisi State University, 2 University Str., 0186 Tbilisi (Georgia)

2010-02-15T23:59:59.000Z

225

Neutrino energy loss rates and positron capture rates on $^{55}$Co for presupernova and supernova physics  

E-Print Network (OSTI)

Proton-neutron quasi-particle random phase approximation (pn-QRPA) theory has recently being used for calculation of stellar weak interaction rates of $fp$-shell nuclide with success. Neutrino losses from proto-neutron stars play a pivotal role to decide if these stars would be crushed into black holes or explode as supernovae. The product of abundance and positron capture rates on $^{55}$Co is substantial and as such can play a role in fine tuning of input parameters of simulation codes specially in the presupernova evolution. Recently we introduced our calculation of capture rates on $^{55}$Co, in a luxurious model space of $7 \\hbar \\omega$, employing the pn-QRPA theory with a separable interaction. Simulators, however, may require these rates on a fine scale. Here we present for the first time an expanded calculation of the neutrino energy loss rates and positron capture rates on $^{55}$Co on an extensive temperature-density scale. These type of scale is appropriate for interpolation purposes and of greater utility for simulation codes. The pn-QRPA calculated neutrino energy loss rates are enhanced roughly up to two orders of magnitude compared with the large-scale shell model calculations and favor a lower entropy for the core of massive stars.

Jameel-Un Nabi; Muhammad Sajjad

2011-08-03T23:59:59.000Z

226

Evaluation of positron emission tomography as a method to visualize subsurface microbial processes  

Science Conference Proceedings (OSTI)

Positron emission tomography (PET) provides spatiotemporal monitoring in a nondestructive manner and has higher sensitivity and resolution relative to other tomographic methods. Therefore, this technology was evaluated for its application to monitor in situ subsurface bacterial activity. To date, however, it has not been used to monitor or image soil microbial processes. In this study, PET imaging was applied as a 'proof-of-principle' method to assess the feasibility of visualizing a radiotracer labeled subsurface bacterial strain (Rahnella sp. Y9602), previously isolated from uranium contaminated soils and shown to promote uranium phosphate precipitation. Soil columns packed with acid-purified simulated mineral soils were seeded with 2-deoxy-2-[{sup 18}F]fluoro-d-glucose ({sup 18}FDG) labeled Rahnella sp. Y9602. The applicability of [{sup 18}F]fluoride ion as a tracer for measuring hydraulic conductivity and {sup 18}FDG as a tracer to identify subsurface metabolically active bacteria was successful in our soil column studies. Our findings indicate that positron-emitting isotopes can be utilized for studies aimed at elucidating subsurface microbiology and geochemical processes important in contaminant remediation.

Kinsella K.; Schlyer D.; Kinsella, K.; Schlyer, D.J.; Fowler, J.S.; Martinez, R.J.; Sobecky, P.A.

2012-01-18T23:59:59.000Z

227

Source Tree Composition  

E-Print Network (OSTI)

Dividing software systems in components improves software reusability as well as software maintainability. Components live at several levels, we concentrate on the implementation level where components are formed by source files, divided over directory structures. Such source code components are usually strongly coupled in the directory structure of a software system. Their compilation is usually controlled by a single global build process. This entangling of source trees and build processes often makes reuse of source code components in different software systems difficult. It also makes software systems inflexible because integration of additional source code components in source trees and build processes is difficult. This paper's subject is to increase software reuse by decreasing coupling of source code components. It is achieved by automized assembly of software systems from reusable source code components and involves integration of source trees, build processes, and configuration processes. Application domains include generative programming, product-line architectures, and commercial off-the-shelf (COTS) software engineering.

Merijn De Jonge

2001-01-01T23:59:59.000Z

228

Frequency Scanned Interferometry for ILC Tracker Alignment  

E-Print Network (OSTI)

In this paper, we report high-precision absolute distance and vibration measurements performed with frequency scanned interferometry. Absolute distance was determined by counting the interference fringes produced while scanning the laser frequency. High-finesse Fabry-Perot interferometers were used to determine frequency changes during scanning. A dual-laser scanning technique was used to cancel drift errors to improve the absolute distance measurement precision. A new dual-channel FSI demonstration system is also presented which is an interim stage toward practical application of multi-channel distance measurement. Under realistic conditions, a precision of 0.3 microns was achieved for an absolute distance of 0.57 meters. A possible optical alignment system for a silicon tracker is also presented.

Hai-Jun Yang; Tianxiang Chen; Keith Riles

2011-09-12T23:59:59.000Z

229

Design and simulation of fast pulsed kicker/bumper units for the positron accumulator ring at APS  

Science Conference Proceedings (OSTI)

In the design of fast pulsed kicker/bumper units for a positron accumulator ring (PAR) at APS, different pulse forming networks (PFN) are considered and different structures for the magnet are studied and simulated. This paper describes some design considerations and computer simulation results of different designs. 4 refs., 6 figs.

Wang, J.; Volk, G.J.

1991-01-01T23:59:59.000Z

230

Simulation of a method for forming a laser-cooled positron plasma A. S. Newbury,* B. M. Jelenkovic,  

E-Print Network (OSTI)

axis at the same frequency as the 9 Be ions . Therefore, a centrifugal separation will occur, forcing beams of high brightness for a number of different ex- periments 4,6,18 . A dense gas of positrons-temperature buffer gas of N2 to provide trapping and cooling. By remov- ing the buffer gas, the base pressure

231

Sources of Thermodynamic Data  

Science Conference Proceedings (OSTI)

...The thermodynamic data summarized in Table 2 are collected from a variety of sources. The certainty with which

232

Next Generation Light Source  

•Next Generation Light Source – Super Thin Light Bulb, Energy Efficient, Long Life, Dimmable, and Uniform Illumination •High Entry Barrier – 71 ...

233

DC source assemblies  

SciTech Connect

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.

Campbell, Jeremy B; Newson, Steve

2013-02-26T23:59:59.000Z

234

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

SciTech Connect

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.

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

235

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

SciTech Connect

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.

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

236

Ion Sources - Cyclotron  

NLE Websites -- All DOE Office Websites (Extended Search)

Sources Sources The 88-Inch Cyclotron is fed by three Electron Cyclotron Resonance (ECR) high-charge-state ion sources, the ECR, the AECR, and VENUS, currently the most powerful ECR ion source in the world. Built to answer the demand for intense heavy ion beams, these high performance ion sources enable the 88-Inch Cyclotron to accelerate beams of ions from hydrogen to uranium. The ECR ion sources allow the efficient use of rare isotopes of stable elements, either from natural or enriched sources. A variety of metallic ion beams are routinely produced in our low temperature oven (up to 600°C) and our high temperature oven (up to 2100°C). Furthermore, the ability to produce "cocktails" (mixtures of beams) for the Berkeley Accelerator Space Effects (BASE) Facility adds tremendously to the flexibility of the 88-Inch Cyclotron.

237

Modulational instability of ion acoustic waves in e-p-i plasmas with electrons and positrons following a q-nonextensive distribution  

Science Conference Proceedings (OSTI)

The propagation of ion acoustic waves (IAWs) in plasmas composed of ions and nonextensive electrons and positrons is investigated. By means of the reduction perturbation technique, a nonlinear Schroedinger equation is derived and the modulation instability (MI) of ion acoustic waves is analyzed in detail. The effects of different ranges of the nonextensive parameter q on the MI are studied. The growth rate of the MI is also given for different values of the q parameter. It is also found that the ratio of the electron temperature to positron temperature and the ratio of the positron density to electron density modify the nature of IAWs instability and the solitary structures.

Eslami, Parvin [Department of Physics, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Mottaghizadeh, Marzieh [Department of Physics, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Pakzad, Hamid Reza [Department of Physics, Bojnourd Branch, Islamic Azad University, Bojnourd (Iran, Islamic Republic of)

2011-10-15T23:59:59.000Z

238

Microsoft PowerPoint - April_07_DOENSF_rev [Compatibility Mode]  

NLE Websites -- All DOE Office Websites (Extended Search)

Global Systems Global Systems John Carwardine, Claude Saunders, Frank Lenkszus 10 May 2007 Americas ILC Schematic Americas 11km SC linacs operating at 31.5 MV/m for 500 GeV Centralized injector j Circular damping rings for electrons and positrons Undulator-based positron source Single IR with 14 mrad crossing angle Dual tunnel configuration for safety and availability Global design effort 2007 DOE/NSF review Global design effort Slide 2 Americas RDR Design & "Value" Costs Americas Summary RDR "Value" Costs The reference design was "frozen" as of 1-Dec-06 for the RDR Value Costs T t l V l C t (FY07) purpose of producing the RDR, including costs. Total Value Cost (FY07) $4.87B Shared The RDR is a snapshot and the design will continue to evolve, due to results of the

239

Spallation Neutron Source, SNS  

NLE Websites -- All DOE Office Websites (Extended Search)

Spallation Neutron Source Spallation Neutron Source Providing the most intense pulsed neutron beams in the world... Accumulator Ring Commissioning Latest Step for Spallation Neutron Source The Spallation Neutron Source, located at Oak Ridge National Laboratory, has passed another milestone on the way to completion this year--the commissioning of the proton accumulator ring. Brookhaven led the design and construction of the accumulator ring, which will allow an order of magnitude more beam power than any other facility in the world. The Spallation Neutron Source (SNS) is an accelerator-based neutron source being built in Oak Ridge, Tennessee, by the U.S. Department of Energy. The figure on the right shows a schematic of the accumulator ring and transport beam lines that are being designed and built by Brookhaven

240

Source and replica calculations  

Science Conference Proceedings (OSTI)

The starting point of the Hiroshima-Nagasaki Dose Reevaluation Program is the energy and directional distributions of the prompt neutron and gamma-ray radiation emitted from the exploding bombs. A brief introduction to the neutron source calculations is presented. The development of our current understanding of the source problem is outlined. It is recommended that adjoint calculations be used to modify source spectra to resolve the neutron discrepancy problem.

Whalen, P.P.

1994-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Dynamic radioactive particle source  

SciTech Connect

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.

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

2012-06-26T23:59:59.000Z

242

AnthroSources  

Science Conference Proceedings (OSTI)

... placed into the HANIM format (www.hanim.org) and existing animation sequences are applied. The original source of the animations comes from ...

243

Locating Sources of Data  

Science Conference Proceedings (OSTI)

Table 4   Guides and directories to sources of materials data and information...1993 The CD-ROM Directory 1993, TFPL Publishing, Washington, DC, 1993.

244

Brochures | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Podcasts Image Gallery external site Video Library Syndicated Feeds (RSS) The Advanced Photon Source: Lighting the Way to a Better Tomorrow aps brochure The APS helps...

245

Publications | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

compendium of information on results from research at the APS. It is the official source for listing APS-related journal articles, conference proceedings and papers,...

246

Divisions | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Chart Argonne Research Divisions APS Research Divisions In May 2002, The Advanced Photon Source was reorganized into three divisions: the Accelerator Systems Division...

247

Sources of Corrosion Information  

Science Conference Proceedings (OSTI)

Table 3   Sources of corrosion information...Sci.chem.electrochem Newsgroup www.groups.google.com/groups?group=sci.chem..electrochem/...

248

Improved ion source  

DOE Patents (OSTI)

A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species,

Leung, K.N.; Ehlers, K.W.

1982-05-04T23:59:59.000Z

249

Radiation Source Replacement Workshop  

Science Conference Proceedings (OSTI)

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.

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

2010-12-01T23:59:59.000Z

250

PORTABLE SOURCE OF RADIOACTIVITY  

DOE Patents (OSTI)

A portable source for radiogiaphy or radiotherapy is described. It consists of a Tl/sup 170/ or Co/sup 60/ source mounted in a rotatable tungsten alloy plug. The plug rotates within a brass body to positions of safety or exposure. Provision is made for reloading and carrying the device safely. (T.R.H.)

Goertz, R.C.; Ferguson, K.R.; Rylander, E.W.; Safranski, L.M.

1959-06-16T23:59:59.000Z

251

Chemical Plume Source Localization  

Science Conference Proceedings (OSTI)

This paper addresses the problem of estimating a likelihood map for the location of the source of a chemical plume using an autonomous vehicle as a sensor probe in a fluid flow. The fluid flow is assumed to have a high Reynolds number. Therefore, the ... Keywords: Autonomous vehicles, Bayesian inference methods, chemical plume tracing, online mapping, online planning, plume source localization

Shuo Pang; J. A. Farrell

2006-10-01T23:59:59.000Z

252

Nonplanar converging and diverging shock waves in the presence of thermal ions in electron-positron plasma  

Science Conference Proceedings (OSTI)

The cylindrical and spherical Korteweg-de Vries-Burger equations have been derived to study the ion acoustic converging and diverging shock waves. The considered plasma is comprised of inertialess electrons, positrons, and inertial thermal ions. It is noticed that the ion temperature, positron concentration, and kinematic viscosity have significant influence on the shock structure and propagation in nonplanar geometries. The strength of shock in spherical geometry is found to dominate over shock strength in cylindrical geometry. The shock wave strength and steepness escalate with time as it moves towards the center and shock enervates as it recedes away from center. The graphical view of the numerical results is presented for illustration. The results may have relevance in the inertial confinement fusion plasmas.

Shah, Asif; Saeed, R. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan); Noaman-ul-Haq, Muhammad [Optics Laboratories, P.O. Box 1021, Islamabad (Pakistan)

2010-07-15T23:59:59.000Z

253

source | OpenEI  

Open Energy Info (EERE)

source source Dataset Summary Description This dataset comes from the Energy Information Administration (EIA), and is part of the 2011 Annual Energy Outlook Report (AEO2011). This dataset is table 17, and contains only the reference case. The dataset uses quadrillion Btu. The data is broken down into marketed renewable energy, residential, commercial, industrial, transportation and electric power. Source EIA Date Released April 26th, 2011 (3 years ago) Date Updated Unknown Keywords Commercial Electric Power Industrial Renewable Energy Consumption Residential sector source transportation Data application/vnd.ms-excel icon AEO2011: Renewable Energy Consumption by Sector and Source- Reference Case (xls, 105 KiB) Quality Metrics Level of Review Peer Reviewed Comment

254

Photonic crystal light source  

DOE Patents (OSTI)

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.

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

2004-07-27T23:59:59.000Z

255

Neutron sources and applications  

Science Conference Proceedings (OSTI)

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.

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

256

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

Science Conference Proceedings (OSTI)

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).

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

257

Microfabricated diffusion source  

DOE Patents (OSTI)

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.

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

2008-07-15T23:59:59.000Z

258

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

Science Conference Proceedings (OSTI)

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.

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

259

Alternative fuel information sources  

DOE Green Energy (OSTI)

This short document contains a list of more than 200 US sources of information (Name, address, phone number, and sometimes contact) related to the use of alternative fuels in automobiles and trucks. Electric-powered cars are also included.

Not Available

1994-06-01T23:59:59.000Z

260

National Synchrotron Light Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Environmental Assessment Environmental Assessment Proposed Upgrade and Improvement of the National Synchrotron Light Source Complex at Brookhaven National Laboratory, Upton, New York This Environmental Assessment addresses the proposed action by the U.S. Department of Energy to upgrade the facilities of the National Synchrotron Light Source Complex, namely the National Synchrotron Light Source (NSLS), the Accelerator Test Facility and the Source Development Laboratory. The environmental effects of a No-Action Alternative as well as a Proposed Action are evaluated in the Environmental Assessment. The “NSLS Environmental Assessment Fact Sheet” link below leads to a one-page summary of the Environmental Assessment. The “NSLS Environmental Assessment” link below leads to the whole 41-page

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Source Remediation vs. Plume  

E-Print Network (OSTI)

This summary paper reviews just some of the extensive scientific literature from the past 20 years on the various aspects of contaminant source remediation and plume management. Some of the major findings of the numerous research projects are presented.

Management Critical Factors; G. Teutsch; H. Rgner; D. Zamfirescu; M. Finkel; M. Bittens

2001-01-01T23:59:59.000Z

262

Sources of Error  

Science Conference Proceedings (OSTI)

...Sources of error in damage tolerance analysis can be classified as: Uncertainty and assumptions in data input Uncertainty due to assumptions about flaws Interpretations of, and assumptions in, stress history Inaccuracies in stress intensity Computer...

263

About | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

the APS Welcome to the Advanced Photon Source Here you will find an introduction and tour of the facility, as well as information about the organizations and opportunities at...

264

Specific Sources of Data  

Science Conference Proceedings (OSTI)

Table 5   Sources of materials data...ASM International, 1989, 1224 pp (C) NIST High Temperature Superconductors Database, Ceramics Division, National Institute of Standards and Technology, Gaithersburg,

265

Bayesian Radiation Source Localization  

Science Conference Proceedings (OSTI)

Locating illicit radiological sources using gamma ray or neutron detection is a key challenge for both homeland security and nuclear nonproliferation. Localization methods using an array of detectors or a sequence of observations in time and space must provide rapid results while accounting for a dynamic attenuating environment. In the presence of significant attenuation and scatter, more extensive numerical transport calculations in place of the standard analytical approximations may be required to achieve accurate results. Numerical adjoints based on deterministic transport codes provide relatively efficient detector response calculations needed to determine the most likely location of a true source. Probabilistic representations account for uncertainty in the source location resulting from uncertainties in detector responses, the approximations that are used, and the potential for nonunique solutions. A Bayesian approach improves on previous likelihood methods for source localization by allowing the incorporation of all available information to help constrain solutions.

Jarman, Kenneth D.; Miller, Erin A.; Wittman, Richard S.; Gesh, Christopher J.

2011-07-01T23:59:59.000Z

266

Spallation Neutron Source  

NLE Websites -- All DOE Office Websites (Extended Search)

D/gim D/gim Spallation Neutron Source SNS is an accelerator-based neutron source. This one-of-a-kind facility pro- vides the most intense pulsed neutron beams in the world. When ramped up to its full beam power of 1.4 MW, SNS will be eight times more powerful than today's best facility. It will give researchers more detailed snapshots of the smallest samples of physical and biological materials than ever before

267

Magnetron sputtering source  

DOE Patents (OSTI)

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.

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

268

Magnetron sputtering source  

DOE Patents (OSTI)

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.

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

1994-08-02T23:59:59.000Z

269

Field emission electron source  

DOE Patents (OSTI)

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.

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

2000-01-01T23:59:59.000Z

270

HIGH VOLTAGE ION SOURCE  

DOE Patents (OSTI)

A device is described for providing a source of molecular ions having a large output current and with an accelerated energy of the order of 600 kv. Ions are produced in an ion source which is provided with a water-cooled source grid of metal to effect maximum recombination of atomic ions to molecular ions. A very high accelerating voltage is applied to withdraw and accelerate the molecular ions from the source, and means are provided for dumping the excess electrons at the lowest possible potentials. An accelerating grid is placed adjacent to the source grid and a slotted, grounded accelerating electrode is placed adjacent to the accelerating grid. A potential of about 35 kv is maintained between the source grid and accelerating grid, and a potential of about 600 kv is maintained between the accelerating grid and accelerating electrode. In order to keep at a minimum the large number of oscillating electrons which are created when such high voltages are employed in the vicinity of a strong magnetic field, a plurality of high voltage cascaded shields are employed with a conventional electron dumping system being employed between each shield so as to dump the electrons at the lowest possible potential rather than at 600 kv.

Luce, J.S.

1960-04-19T23:59:59.000Z

271

Inter-sourcing: alternative IT sourcing solutions using student interns  

Science Conference Proceedings (OSTI)

Information Technology (IT) sourcing decisions are motivated by cost savings, skills acquisition, and staffing flexibility. The research in progress introduces a new alternative in sourcing, inter-sourcing. This practice incorporates the benefits of ... Keywords: inter-sourcing, it education, it internships, it sourcing

Mari W. Buche

2013-05-01T23:59:59.000Z

272

ISG8-RF Sources  

NLE Websites -- All DOE Office Websites (Extended Search)

RF Sources - (WG3) RF Sources - (WG3) Orange Rm Yong Ho Chin, Christopher Nantista, and Sami G. Tantawi Parallel Sessions: Working Groups: WG1: Parameters, Design, Instrumentation and Tuning WG2: Damping Rings and ATF WG3: RF Sources WG4:Structures WG5: Ground Motion; Site Requirements and Investigations Monday Morning 9:00-10:30 Plenary Coffee Break 11:00-12:00 Planning Session. Monday Afternoon 13:30-15:30 High Gradient Issues (Joint with working group 4) Coffee Break 16:00-16:30 The 8-Pack Project -- D. Atkinson 16:30-17:30 High Gradient Issues and Discussions Continued. Tuesday Morning 9:30-10:30 Klystrons 9:30-10:00 Status of PPM Klystron Development for JLC -- Y. H. Chin 10:00-10:30 Design of 150MW Multi-Beam Klystron -- S. Matsumoto Coffee Break 11:00-11:30 Klystron Development at SLAC -- G. Caryotakis

273

Photon Source Parameters  

NLE Websites -- All DOE Office Websites (Extended Search)

Photon Source Parameters Photon Source Parameters Photon Source Parameters Print Summary Graph of Brightness Curves for All Insertion Devices Insertion Device and Bend Magnet Parameters Bend Magnet Superbend Magnet U30 Undulator U50 Undulator U80 Undulator U100 Undulator W114 Wiggler The ALS has six elliptically polarizing undulators, two in straight 4, two in straight 11, and one each in straights 6 and 7. All are arranged with chicanes so that two such devices can be installed to feed two independent beamlines. They can be used in a variety of polarization modes, including circular, elliptical, horizontal, and vertical. These modes can be chosen by appropriate phasing of the magnet rows. The brightness and flux curves below are shown for horizontal and circular polarization. Curves for elliptical and vertical polarization are similar to the horizontal polarization curve, but the minimum photon energy is higher.

274

Source Emissions and Transport  

NLE Websites -- All DOE Office Websites (Extended Search)

electron micrograph image, Lara Gundel with instrumentation electron micrograph image, Lara Gundel with instrumentation Source Emissions and Transport Investigators conduct research here to characterize and better understand the sources of airborne volatile, semi-volatile and particulate organic pollutants in the indoor environment. This research includes studies of the physical and chemical processes that govern indoor air pollutant concentrations and exposures. The motivation is to contribute to the reduction of potential human health effects. Contacts Randy Maddalena RLMaddalena@lbl.gov (510) 486-4924 Mark Mendell MJMendell@lbl.gov (510) 486-5762 Links Pollutant Sources, Dynamics and Chemistry Group Batteries and Fuel Cells Buildings Energy Efficiency Electricity Grid Energy Analysis Energy Technologies Environmental Impacts

275

Heat Source Lire,  

NLE Websites -- All DOE Office Websites (Extended Search)

Source Lire, Source Lire, (liayrICS-25 ) tooling Tulles (Ai 1,06:1) - 11 (31.118 Module Stack Thermoelectric Module:, (14) ltcal L/Mr r a it i lli tisli Block Mounting Interface MMRTG Design Housing (At 2219) Fin (At Go63) Thermal Insulation (Min-K & Microtherm) Space Radioisotope Power Systems Multi-Mission Radioisotope Thermoelectric Generator January 2008 What is a Multi-Mission Radioisotope Thermoelectric Generator? Space exploration missions require safe, reliable, long-lived power systems to provide electricity and heat to spacecraft and their science instruments. A uniquely capable source of power is the radioisotope thermoelectric generator (RTG) - essentially a nuclear battery that reliably converts heat into electricity. The Department of Energy and NASA are developing

276

Source Selection Guide  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Source Selection Source Selection Overview This chapter provides guidance to the acquisition team on conducting source selection in accordance with Part 15 of the Federal Acquisition Regulation (FAR). Background The mid 1990's was a time of significant change in many areas of procurement, particularly in the introduction of new tools and processes that help the procurement professional better meet the needs of demanding customers. The passage of the Federal Acquisition Streamlining Act in 1994 and the Federal Acquisition Reform Act in 1995 , coupled with Government-wide and Department of Energy (DOE) contract reform efforts not only changed traditional procurement processes but also changed the role of the procurement professional. No longer are procurement

277

Dual source heat pump  

DOE Patents (OSTI)

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.

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

1982-01-01T23:59:59.000Z

278

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

SciTech Connect

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.

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

279

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

Science Conference Proceedings (OSTI)

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 (median), although the findings suggested a trend toward improved LRFS: 96% 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.

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

280

INEEL Source Water Assessment  

SciTech Connect

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.

Sehlke, Gerald

2003-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Identifying PM10 Sources and Estimating Source Contributions...  

NLE Websites -- All DOE Office Websites (Extended Search)

of ammonium nitric, secondary aerosol of ammonium sulfate, and incinerator and fuel oil burning sources. The source mass profiles derived by the PMF model well describe the...

282

FABRICATION OF NEUTRON SOURCES  

DOE Patents (OSTI)

A method is presented for preparing a neutron source from polonium-210 and substances, such as beryllium and boron, characterized by emission of neutrons upon exposure to alpha particles from the polonium. According to the invention, a source is prepared by placing powdered beryllium and a platinum foil electroplated with polonium-2;.0 in a beryllium container. The container is sealed and then heated by induction to a temperature of 450 to 1100 deg C to volatilize the polonium off the foil into the powder. The heating step is terminated upon detection of a maximum in the neutron flux level.

Birden, J.H.

1959-04-21T23:59:59.000Z

283

COMBUSTION SOURCES OF NITROGEN COMPOUNDS  

E-Print Network (OSTI)

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

Brown, Nancy J.

2011-01-01T23:59:59.000Z

284

Selective ion source  

DOE Patents (OSTI)

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.

Leung, Ka-Ngo (Hercules, CA)

1996-01-01T23:59:59.000Z

285

Strategic Sourcing | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Strategic Sourcing Strategic Sourcing Strategic Sourcing Energy Wide Strategic Sourcing (EWSS) DOE leadership has recognized that benefits could be achieved at the federal level through an organized, systematic and collaborative approach to acquiring commonly used goods and services. The DOE strategic sourcing program builds upon historical accomplishments as well as establishes a more cohesive and disciplined program, consistent with OMB's direction, for the conduct of DOE future strategic sourcing efforts. The DOE and NNSA Senior Procurement Executives have created a strategic sourcing capability and organizational components to identify federal strategic sourcing opportunities and coordinate strategic thinking. To date, this program has identified a number of opportunities; particularly in the areas of

286

Book sources | Open Energy Information  

Open Energy Info (EERE)

Community Linked Data Special page Share this page on Facebook icon Twitter icon Book sources Jump to: navigation, search Search for book sources ISBN: Go Retrieved from...

287

Book sources | Open Energy Information  

Open Energy Info (EERE)

Community Linked Data Special page Share this page on Facebook icon Twitter icon Book sources Jump to: navigation, search Search for book sources ISBN: 9781603580304 Go...

288

WIPP Opportunities - Procurement - Sources Sought  

NLE Websites -- All DOE Office Websites (Extended Search)

Procurement Sources Sought This page displays a listing Sources Sought. If you are interested in submitting an outline, please contact the cognizant buyer to find out more. Please...

289

Energy Sources | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Sources Energy Sources Renewable Energy Learn more about Solar, Water, Biomass, Geothermal and Wind Energy. Read more Nuclear Learn more about how we use Nuclear Energy. Read more...

290

Energy Sources | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Science & Innovation Energy Sources Energy Sources Renewable Energy Learn more about Solar, Water, Biomass, Geothermal and Wind Energy. Read more Nuclear Learn more about how we...

291

Grid size convergence study of the finite-element method applied to electron, positron-molecule scattering  

SciTech Connect

The convergence of the fifth order Hermite polynomial, Finite Element method is studied for electron and positron scattering from N{sub 2} and C{sub 2}H{sub 2} in the static approximation in spherical coordinates. Results are compared with a single-center method employing spherical harmonic expansions in order to compare grid size requirements to number of partial waves in the single-center method. Results will be presented at the level of phase shifts, integrated and differential cross sections.

Weatherford, C.A.; Khurana, I.

1993-05-01T23:59:59.000Z

292

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)

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 ...

Basil, A.

293

In-situ characterization of free-volume holes in polymer thin films under controlled humidity conditions with an atmospheric positron probe microanalyzer  

Science Conference Proceedings (OSTI)

A pulsed, slow positron beam, with a diameter of 200 {mu}m, was extracted into air through a thin SiN window of an atmospheric positron probe microanalyzer (PPMA), and used to measure the ortho-positronium lifetimes {tau} in polyvinyl alcohol and polycaprolactam sub-{mu}m-thick films. By measuring the variation of {tau} as a function of relative humidity, the effect of water molecules on the hole sizes, deduced from {tau}, was examined for the films with consideration to the chain mobility. The results demonstrate the usefulness of the atmospheric PPMA to the in-situ characterization of nanoscopic holes in thin films under practical conditions.

Zhou Wei; Oshima, Nagayasu; O'Rourke, Brian E.; Kuroda, Ryunosuke; Suzuki, Ryoichi [Research Institute of Instrumentation Frontier (RIIF), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Chen Zhe; Ito, Kenji [Metrology Institute of Japan (MIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565 (Japan); Yanagishita, Hiroshi [Research Institute for Innovation in Sustainable Chemistry (ISC), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565 (Japan); Tsutsui, Takuro; Uedono, Akira [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Hayashizaki, Noriyosu [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Meguro, Tokyo 152-8850 (Japan)

2012-07-02T23:59:59.000Z

294

(/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)

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.

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

1986-04-17T23:59:59.000Z

295

Posters | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Your Cart (0 Posters) Your Cart (0 Posters) Your cart is empty. checkout Subtotal: $0.00 update empty Posters Order a printed APS poster! 11 in. x 17 in. prints will be mailed in the order requests are received. 36 in. x 36 in. posters will be sent to school addresses once all orders are processed. The Advanced Photon Source Is The Advanced Photon Source Is Qty: 1 add to cart Technologies from Materials Science Technologies from Materials Science Qty: 1 add to cart Materials Under Extreme Pressure Materials Under Extreme Pressure Qty: 1 add to cart Biological Macromolecules in Action Biological Macromolecules in Action Qty: 1 add to cart Journey to the Center of the Earth Journey to the Center of the Earth Qty: 1 add to cart Earthshaking Monitor Earthshaking Monitor Qty: 1 add to cart Imaging with X-rays

296

Photon Source Parameters  

NLE Websites -- All DOE Office Websites (Extended Search)

Photon Source Parameters Print Photon Source Parameters Print Summary Graph of Brightness Curves for All Insertion Devices Insertion Device and Bend Magnet Parameters Bend Magnet Superbend Magnet U30 Undulator U50 Undulator U80 Undulator U100 Undulator W114 Wiggler The ALS has six elliptically polarizing undulators, two in straight 4, two in straight 11, and one each in straights 6 and 7. All are arranged with chicanes so that two such devices can be installed to feed two independent beamlines. They can be used in a variety of polarization modes, including circular, elliptical, horizontal, and vertical. These modes can be chosen by appropriate phasing of the magnet rows. The brightness and flux curves below are shown for horizontal and circular polarization. Curves for elliptical and vertical polarization are similar to the horizontal polarization curve, but the minimum photon energy is higher.

297

Photon Source Parameters  

NLE Websites -- All DOE Office Websites (Extended Search)

Photon Source Parameters Print Photon Source Parameters Print Summary Graph of Brightness Curves for All Insertion Devices Insertion Device and Bend Magnet Parameters Bend Magnet Superbend Magnet U30 Undulator U50 Undulator U80 Undulator U100 Undulator W114 Wiggler The ALS has six elliptically polarizing undulators, two in straight 4, two in straight 11, and one each in straights 6 and 7. All are arranged with chicanes so that two such devices can be installed to feed two independent beamlines. They can be used in a variety of polarization modes, including circular, elliptical, horizontal, and vertical. These modes can be chosen by appropriate phasing of the magnet rows. The brightness and flux curves below are shown for horizontal and circular polarization. Curves for elliptical and vertical polarization are similar to the horizontal polarization curve, but the minimum photon energy is higher.

298

Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Home Home Group Members Accelerator Magnets Insertion Devices Facilities Presentations & Publications Internal Magnetic Devices Group The primary mission of the Magnetic Devices (MD) Group is to design, build, and maintain Insertion Devices (IDs) that are reliable and transparent to the electron beam at the Advanced Photon Source (APS). The majority of IDs at the APS are conventional planar hybrid undulators, but an essential part of the mission is to develop novel IDs, such as short-period superconducting undulators and long-period electromagnetic undulators. The capabilities of APS IDs are matched to users' experimental needs. The mission also includes magnetic tuning of the IDs to ensure their near-ideal performance as x-ray sources and calculations to predict the radiation

299

Photon Source Parameters  

NLE Websites -- All DOE Office Websites (Extended Search)

Photon Source Parameters Print Photon Source Parameters Print Summary Graph of Brightness Curves for All Insertion Devices Insertion Device and Bend Magnet Parameters Bend Magnet Superbend Magnet U30 Undulator U50 Undulator U80 Undulator U100 Undulator W114 Wiggler The ALS has six elliptically polarizing undulators, two in straight 4, two in straight 11, and one each in straights 6 and 7. All are arranged with chicanes so that two such devices can be installed to feed two independent beamlines. They can be used in a variety of polarization modes, including circular, elliptical, horizontal, and vertical. These modes can be chosen by appropriate phasing of the magnet rows. The brightness and flux curves below are shown for horizontal and circular polarization. Curves for elliptical and vertical polarization are similar to the horizontal polarization curve, but the minimum photon energy is higher.

300

Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

0 Advanced Photon Source 0 Advanced Photon Source A U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences national synchrotron x-ray research facility Search Button About Welcome Overview Visiting the APS Mission & Goals Find People Organization Charts Committees Job Openings User Information Prospective Users New Users Current Users APS User Portal Macromolecular Crystallographers Administrators Find a Beamline Apply for Beam Time Contacts Calendars Community Scientific Access Site Access Training Science & Education Science & Research Highlights Conferences Seminars Publications Annual Reports APS Upgrade Courses and Schools Graduate Programs Scientific Software Media Center Calendar of Events APS News User News Argonne/APS Press Releases Argonne/APS Feature Stories Argonne/APS In The News

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Comparisons with Other sources  

U.S. Energy Information Administration (EIA) Indexed Site

Estimates Compared with Other sources Estimates Compared with Other sources The following seven graphs were prepared to give a sense of the variation and confidence level of the EIA-914 estimates. Each graph shows the reported sample production (the starting point for making an estimate), the EIA-914 estimates, State reported data, HPDI reported data, and Lippman Consulting data for comparison. State data are obtained directly from the States usually via a State agency web site as a monthly total. HPDI is a commercial data vender. They acquire data from all the States and provide it to EIA in a single format and query system at the well or lease level. EIA then sums this data to the operator level and State level. HPDI data typically lag the State data by 1 or 2 months.

302

Photon Source Parameters  

NLE Websites -- All DOE Office Websites (Extended Search)

Photon Source Parameters Print Photon Source Parameters Print Summary Graph of Brightness Curves for All Insertion Devices Insertion Device and Bend Magnet Parameters Bend Magnet Superbend Magnet U30 Undulator U50 Undulator U80 Undulator U100 Undulator W114 Wiggler The ALS has six elliptically polarizing undulators, two in straight 4, two in straight 11, and one each in straights 6 and 7. All are arranged with chicanes so that two such devices can be installed to feed two independent beamlines. They can be used in a variety of polarization modes, including circular, elliptical, horizontal, and vertical. These modes can be chosen by appropriate phasing of the magnet rows. The brightness and flux curves below are shown for horizontal and circular polarization. Curves for elliptical and vertical polarization are similar to the horizontal polarization curve, but the minimum photon energy is higher.

303

Overview | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

APS Overview: APS Overview: Introduction APS Systems Map LINAC Booster Synchrotron Storage Ring Insertion Devices Experiment Hall LOMs & Beamlines Overview of the APS The Advanced Photon Source (APS) at the U.S. Department of Energy's Argonne National Laboratory provides this nation's (in fact, this hemisphere's) brightest storage ring-generated x-ray beams for research in almost all scientific disciplines. Photo: Aerial Photo of APS Aerial photo of the Advanced Photon Source These x-rays allow scientists to pursue new knowledge about the structure and function of materials in the center of the Earth and in outer space, and all points in between. The knowledge gained from this research can impact the evolution of combustion engines and microcircuits, aid in the development of new pharmaceuticals, and pioneer nanotechnologies whose

304

National Synchrotron Light Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Report 2001 Report 2001 National Synchrotron Light Source For the period October 1, 2000 through September 30, 2001 Introduction Science Highlights Year in Review Operations Publications Abstracts Nancye Wright & Lydia Rogers The National Synchrotron Light Source Department is supported by the Office of Basic Energy Sciences United States Department of Energy Washington, D.C. Brookhaven National Laboratory Brookhaven Science Associates, Inc. Upton, New York 11973 Under Contract No. DE-AC02-98CH10886 Mary Anne Corwin Steven N. Ehrlich & Lisa M. Miller Managing Editor Science Editors Production Assistants Cover images (clockwise from top left) 1. from Science Highlight by K.R. Rajashankar, M.R. Chance, S.K. Burley, J. Jiang, S.C. Almo, A. Bresnick, T. Dodatko, R. Huang, G. He,

305

Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Tomography Interest Group Contact: Robert Winarski, Center for Nanoscale Materials winarski@anl.gov Contact: Francesco De Carlo, Advanced Photon Source decarlo@aps.anl.gov The tomography special interest group of the Advanced Photon Source (APS) at Argonne National Laboratory has been created to promote awareness of the tomography facilities at the APS and to foster communications between the various research groups. Through this group, we believe we can build a strong user community for tomography. The following beamlines have active tomography research programs: 2-BM-B (XOR) http://www.aps.anl.gov/Xray_Science_Division/Xray_Microscopy_and_Imaging/Science_and_Research/Techniques/Tomography/index.html Information about the beamline: http://beam.aps.anl.gov/pls/apsweb/beamline_display_pkg.display_beamline?p_beamline_num_c=31

306

Filtered cathodic arc source  

DOE Patents (OSTI)

Disclosed is a continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45{degrees} to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles.

Falabella, S.; Sanders, D.M.

1992-12-31T23:59:59.000Z

307

Evaluated teletherapy source library  

DOE Patents (OSTI)

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.

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

2000-01-01T23:59:59.000Z

308

Calibrated vapor generator source  

DOE Patents (OSTI)

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.

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

309

Calibrated vapor generator source  

DOE Patents (OSTI)

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.

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

310

Filtered cathodic arc source  

DOE Patents (OSTI)

A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge is described. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45[degree] to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles. 3 figures.

Falabella, S.; Sanders, D.M.

1994-01-18T23:59:59.000Z

311

Open Source Physics  

E-Print Network (OSTI)

Open Source Physics (Brown, 2012; Christian, 2010; Esquembre, 2012; Hwang, 2010) empowers teachers and students to create and use these free tools with the associated intellectual property rights given to customise (Wee & Mak, 2009) the computer models/tools to suit their teaching and learning needs. Open Source Physics (OSP) focuses on design of computer models, such as Easy Java Simulations (EJS) and the use of video modeling and analysis (Tracker). They allow students to investigate, explore and analyse data which is either real or simulated. The OSP approach helps users overcome barriers in creating, using and scaling up meaningful ICT use in education. In Singapore, teachers and students have created or customised existing computer models to design and re-purpose EJS models to suit their context and learning needs. Tracker tools allow students to analyse different aspects of a physics phenomena to deepen their understanding of abstract physics concepts. Using Tracker, students record the motion of ob...

Wee, Loo Kang

2013-01-01T23:59:59.000Z

312

Voltage controlled current source  

DOE Patents (OSTI)

A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

Casne, Gregory M. (Pittsburgh, PA)

1992-01-01T23:59:59.000Z

313

FABRICATION OF NEUTRON SOURCES  

DOE Patents (OSTI)

A method is presented for preparing a more efficient neutron source comprising inserting in a container a quantity of Po-210, inserting B powder coated with either Ag, Pt, or Ni. The container is sealed and then slowly heated to about 450 C to volatilize the Po and effect combination of the coated powder with the Po. The neutron flux emitted by the unit is moritored and the heating step is terminated when the flux reaches a maximum or selected level.

Birden, J.H.

1959-01-20T23:59:59.000Z

314

Compact superradiant Cerenkov source  

Science Conference Proceedings (OSTI)

An economical, coherent, and widely tunable source does not exist spanning the far-infrared electromagnetic spectral range of 50-1000 {mu}m in wavelength. The Cerenkov free-electron laser (CFEL) is a promising candidate. This report describes an experimental investigation of a compact CFEL driven by a high-quality low-energy electron beam. Cerenkov emission and strong gain but remarkably low output coupling were observed.

Owens, I.J.; Brownell, J.H. [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755-3528 (United States)

2005-05-15T23:59:59.000Z

315

High current ion source  

DOE Patents (OSTI)

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.

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

316

Negative ion source  

DOE Patents (OSTI)

A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reeccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200.degree. to 500.degree. for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

Delmore, James E. (Idaho Falls, ID)

1987-01-01T23:59:59.000Z

317

Open-Source GIS  

SciTech Connect

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.

Vatsavai, Raju [ORNL; Burk, Thomas E [University of Minnesota; Lime, Steve [Minnesota Department of Natural Resources

2012-01-01T23:59:59.000Z

318

Improved negative ion source  

DOE Patents (OSTI)

A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reaccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200 to 500/sup 0/C for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

Delmore, J.E.

1984-05-01T23:59:59.000Z

319

The probability distribution of the number of electron-positron pairs produced in a uniform electric field  

E-Print Network (OSTI)

The probability-generating function of the number of electron-positron pairs produced in a uniform electric field is constructed. The mean and variance of the numbers of pairs are calculated, and analytical expressions for the probability of low numbers of electron-positron pairs are given. A recursive formula is derived for evaluating the probability of any number of pairs. In electric fields of supercritical strength |eE| > \\pi m^2/ \\ln 2, where e is the electron charge, E is the electric field, and m is the electron mass, a branch-point singularity of the probability-generating function penetrates the unit circle |z| = 1, which leads to the asymptotic divergence of the cumulative probability. This divergence indicates a failure of the continuum limit approximation. In the continuum limit and for any field strength, the positive definiteness of the probability is violated in the tail of the distribution. Analyticity, convergence, and positive definiteness are restored upon the summation over discrete levels of electrons in the normalization volume. Numerical examples illustrating the field strength dependence of the asymptotic behavior of the probability distribution are presented.

M. I. Krivoruchenko

2012-06-18T23:59:59.000Z

320

Sources of tritium  

SciTech Connect

A review of tritium sources is presented. The tritium production and release rates are discussed for light water reactors (LWRs), heavy water reactors (HWRs), high temperature gas cooled reactors (HTGRs), liquid metal fast breeder reactors (LMFBRs), and molten salt breeder reactors (MSBRs). In addition, release rates are discussed for tritium production facilities, fuel reprocessing plants, weapons detonations, and fusion reactors. A discussion of the chemical form of the release is included. The energy producing facilities are ranked in order of increasing tritium production and release. The ranking is: HTGRs, LWRs, LMFBRs, MSBRs, and HWRs. The majority of tritium has been released in the form of tritiated water.

Phillips, J.E.; Easterly, C.E.

1980-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

SOURCE TERMS IN THE TRANSIENT SEEPAGE EQUATION  

E-Print Network (OSTI)

Equation; Pore Pressure Generation; Sources; Source Terms)In this paper, sources involving the generation of mass areincludes source terms for both fluid mass generation and

Narasimhan, T.N.

2013-01-01T23:59:59.000Z

322

About the creation of proton-anti-proton pair at electron-positron collider in the energy range of the mass $\\Psi(3770)$  

E-Print Network (OSTI)

The process of electron--positron annihilation into proton--antiproton pair is considered within the vicinity of $\\psi(3770)$ resonance. The interference between the pure electromagnetic intermediate state and the $\\psi(3770)$ state is evaluated. It is shown that this interference is destructive and the relative phase between these two contributions is large ($\\phi_0 \\approx 250^o$).

Ahmadov, A I; Kuraev, E A; Wang, P

2013-01-01T23:59:59.000Z

323

About the creation of proton-anti-proton pair at electron-positron collider in the energy range of the mass $?(3770)$  

E-Print Network (OSTI)

The process of electron--positron annihilation into proton--antiproton pair is considered within the vicinity of $\\psi(3770)$ resonance. The interference between the pure electromagnetic intermediate state and the $\\psi(3770)$ state is evaluated. It is shown that this interference is destructive and the relative phase between these two contributions is large ($\\phi_0 \\approx 250^o$).

A. I. Ahmadov; Yu. M. Bystritskiy; E. A. Kuraev; P. Wang

2013-04-03T23:59:59.000Z

324

Observation of differences between low-energy electron- and positron-diffraction structural determinations of the cleavage faces of CdSe  

Science Conference Proceedings (OSTI)

Low-energy positron diffraction (LEPD) is used in conjunction with low-energy electron diffraction (LEED) to determine the relaxed atomic geometries of the CdSe cleavage surfaces. The LEPD analyses yield optimal fits at smaller top-layer perpendicular relaxations than LEED for both cleavage faces, and significantly better agreement between theoretical and experimental intensity profiles.

Horsky, T.N.; Brandes, G.R.; Canter, K.F.; Duke, C.B.; Horng, S.F.; Kahn, A.; Lessor, D.L.; Mills A.P. Jr.; Paton, A.; Stevens, K.; and others

1989-04-17T23:59:59.000Z

325

Manhattan Project: Sources and Notes  

Office of Scientific and Technical Information (OSTI)

SOURCES AND NOTES SOURCES AND NOTES Resources > Sources Below are the collected specific notes for the text and images used on the pages of this web site. For a discussion of the most important works on the Manhattan Project, see the "Suggested Readings." For a general discussion of the use of sources in this web site, see "A Note on Sources." To scan the sources and notes for various categories, choose from the list below. To view the sources and notes for a specific web page, see the footnote at the bottom of each page (exceptions include this page and the home page; the sources and notes for the home page are the first ones listed below). Home Events 1890s-1939: Atomic Discoveries 1939-1942: Early Government Support 1942: Difficult Choices

326

Radiological Source Registry and Tracking  

NLE Websites -- All DOE Office Websites (Extended Search)

Radiological Source Registry and Tracking (RSRT) Radiological Source Registry and Tracking (RSRT) Home HSS Logo Radiological Source Registry and Tracking (RSRT) Department of Energy (DOE) Notice N 234.1 Reporting of Radioactive Sealed Sources has been superseded by DOE Order O 231.1B Environment, Safety and Health Reporting. O 231.1B identifies the requirements for centralized inventory and transaction reporting for radioactive sealed sources. Each DOE site/facility operator that owns, possesses, uses or maintains in custody those accountable radioactive sealed sources identified in Title 10 Code of Federal Regulation Part 835, Occupational Radiation Protection (10 CFR 835), Appendix E, and International Atomic Energy Agency (IAEA) Categories 1 and 2 radioactive sealed sources identified in Attachment 5, Appendix A of O 321.1B, will submit information to the DOE Radiological Source Registry and Tracking (RSRT) System.

327

National Synchrotron Light Source  

NLE Websites -- All DOE Office Websites (Extended Search)

All Documents listed below are part of the Photon Sciences Directorate and All Documents listed below are part of the Photon Sciences Directorate and will be updated as needed. Photon Sciences ESH Standard Operating Procedures (SOPs) SOP No. Standard Operating Procedure for: LS-ES-0002 Procedure for Acid Etching of Silicon and Germanium Crystals LS-ESH-0004 NSLS Operations Group Chemical Spill and Gas Release Response LS-ESH-0010 VUV Injection Shutter LOTO LS-ESH-0012 LINAC LOTO LS-ESH-0013 Controlled Access to the VUV Ring LS-ESH-0014 Radiation Safety Interlocks at the National Synchrotron Light Source LS-ESH-0019 Beam Line Configuration Control Checklist Requirements LS-ESH-0020 Biosafety Requirements at the NSLS LS-ESH-0021 Biosafety Level 2 work at the NSLS/ A Technical Basis LS-ESH-0022 Beam Line Configuration Control Checklist Requirements

328

Welcome | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Welcome Welcome Aerial view of APS Aerial view of the APS Welcome to the Advanced Photon Source (APS) at Argonne National Laboratory. Whether you are a current or potential scientific user of our unique facility or are simply interested in learning more about the APS, we are delighted that you are visiting our website. The APS is funded by the Office of Science, Office of Basic Energy Sciences in the U.S. Department of Energy. We operate a National User Facility that is open to everyone who has a need for extremely brilliant x-ray photon beams. The APS is one of the most technologically complex machines in the world. This premier national research facility provides the brightest x-ray beams in the Western Hemisphere to more than 5,000 (and growing) scientists from

329

Thulium-170 heat source  

SciTech Connect

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.

Walter, C.E.; Van Konynenburg, R.; VanSant, J.H.

1990-09-06T23:59:59.000Z

330

Thulium-170 heat source  

DOE Patents (OSTI)

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.

Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

1992-01-01T23:59:59.000Z

331

Multiple source heat pump  

DOE Patents (OSTI)

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.

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

332

Interferometry using undulator sources  

Science Conference Proceedings (OSTI)

Optical systems for extreme ultraviolet (EUV) lithography need to use optical components with subnanometer surface figure error tolerances to achieve diffraction-limited performance [M.D. Himel, in {ital Soft} {ital X}-{ital Ray} {ital Projection} {ital Lithography}, A.M. Hawryluk and R.H. Stulen, eds. (OSA, Washington, D.C., 1993), {bold 18}, 1089, and D. Attwood {ital et} {ital al}., Appl. Opt. {bold 32}, 7022 (1993)]. Also, multilayer-coated optics require at-wavelength wavefront measurement to characterize phase effects that cannot be measured by conventional optical interferometry. Furthermore, EUV optical systems will additionally require final testing and alignment at the operational wavelength for adjustment and reduction of the cumulative optical surface errors. Therefore, at-wavelength interferometric measurement of EUV optics will be the necessary metrology tool for the successful development of optics for EUV lithography. An EUV point diffraction interferometer (PDI) has been developed at the Center for X-Ray Optics (CXRO) and has been already in operation for a year [K. Goldberg {ital et} {ital al}., in {ital Extreme} {ital Ultra} {ital Lithography}, D.T. Attwood and F. Zernike, eds. (OSA, Washington, D.C., 1994), K. Goldberg {ital et} {ital al}., Proc. SPIE {bold 2437}, to be published, and K. Goldberg {ital et} {ital al}., J. Vac. Sci. Technol. B {bold 13}, 2923 (1995)] using an undulator radiation source and coherent optics beamline at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. An overview of the PDI interferometer and some EUV wavefront measurements obtained with this instrument will be presented. In addition, future developments planned for EUV interferometry at CXRO towards the measurement of actual EUV lithography optics will be shown. {copyright} {ital 1996 American Institute of Physics.}

Beguiristain, R.; Goldberg, K.A.; Tejnil, E.; Bokor, J.; Medecki, H.; Attwood, D.T.; Jackson, K. [Center for X-ray Optics, Lawrence Berkeley Laboratory, 1 Cyclotron Rd., MS 2-400, Berkeley, CA 94720 (United States)

1996-09-01T23:59:59.000Z

333

Tracking of Moving Radioactive Sources  

Devices that detect the sources of unsecured nuclear materials are currently limited in their capabilities, ... City halls, public streets, hospitals ...

334

Sources - CECM - Simon Fraser University  

E-Print Network (OSTI)

help · annotate · Contents Next: References Up: RamanujanModular Equations, Previous: Ramanujan's sum. Sources. [Annotate] · [Shownotes]. References [7] ...

335

Neutrino and Electron-positron Pair Emission from Phase-induced Collapse of Neutron Stars to Quark Stars  

E-Print Network (OSTI)

We study the energy released from phase-transition induced collapse of neutron stars, which results in large amplitude stellar oscillations. To model this process we use a Newtonian hydrodynamic code, with a high resolution shock-capturing scheme. The physical process considered is a sudden phase transition from normal nuclear matter to a mixed phase of quark and nuclear matter. We show that both the temperature and the density at the neutrinosphere oscillate with time. However, they are nearly 180 degree out of phase. Consequently, extremely intense, pulsating neutrino/antineutrino and leptonic pair fluxes will be emitted. During this stage several mass ejecta can be ejected from the stellar surface by the neutrinos and antineutrinos. These ejecta can be further accelerated to relativistic speeds by the electron/positron pairs, created by the neutrino and antineutrino annihilation outside the stellar surface. We suggest that this process may be a possible mechanism for short Gamma-Ray Bursts.

Cheng, K S

2010-01-01T23:59:59.000Z

336

Production of relativistic anti-hydrogen atoms by pair production with positron capture and measurement of the Lamb shift  

DOE Green Energy (OSTI)

A beam of relativistic antihydrogen atoms-the bound state ({bar p}e{sup +}){minus} can be created by circulating the beam of an antiproton storage ring through an internal gas target. An antiproton which passes through the Coulomb field of a nucleus will create e{sup +}e{sup {minus}} pairs, and antihydrogen will form when a positron is created in a bound instead of continuum state about the antiproton. The cross section for this process is roughly I Z{sup 2} pb for antiproton momenta above 6 GeV/c. A sample of 200 antihydrogen atoms in a low-emittance, neutral beam will be made in 1994 as an accidental byproduct of Fermilab experiment E760. We describe a simple experiment, Fermilab Proposal P862, which can detect this beam, and outline how a sample of a few-10{sup 4} atoms can be used to measure the antihydrogen Lamb shift to 1%.

Munger, C.T.; Brodsky, S.J. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Schmidt, I. [Universidad Tecnica Federico Santa Maria, Valparaiso (Chile)

1992-09-01T23:59:59.000Z

337

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

SciTech Connect

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.

Zalutsky, M.R.

1997-02-01T23:59:59.000Z

338

Development of a CW Superconducting RF Booster Cryomodule for Future Light Sources  

Science Conference Proceedings (OSTI)

Future light sources based on seeded free electron lasers (FEL) have the potential to increase the soft xray flux by several orders of magnitude with short bunch lengths to probe electron structure and dynamics. A low emittance, high rep-rate radio frequency (RF) photocathode electron gun will generate the electron beam that will require very stringent beam control and manipulation through the superconducting linear accelerator to maintain the high brightness required for an x-ray FEL. The initial or booster cavities of the superconducting radio frequency (SRF) linear accelerator will require stringent control of transverse kicks and higher order modes (HOM) during the beam manipulation and conditioning that is needed for emittance exchange and bunch compression. This SBIR proposal will develop, fabricate and test a continuous-wave SRF booster cryomodule specifically for this application. Phase I demonstrated the technical feasibility of the project by completing the preliminary SRF cavity and cryomodule design and its integration into an R&D test stand for beam studies at Lawrence Berkeley National Laboratory (LBNL). The five-cell bulk niobium cavities operate at 750 MHz, and generate 10 MV each with strong HOM damping and special care to eliminate transverse kicks due to couplers. Due to continuous-wave operation at fairly modest beam currents and accelerating gradients the complexity of the two cavity cryomodule is greatly reduced compared to an ILC type system. Phase II will finalize the design, and fabricate and test the booster cryomodule. The cryomodule consists of two five-cell cavities that will accelerate megahertz bunch trains with nano-coulomb charge. The accelerating gradient is a very modest 10 MV/m with peak surface fields of 20 MV/m and 42.6 mT. The cryogenic system operates at 2 K with a design dynamic load of 20 W and total required cryogenic capacity of 45 W. The average beam current of up to 1 mA corresponds to a beam power of 10 kW per 5- cell cavity and will require 20 kW of RF power for transmission, control and regulation. The RF power will be supplied by a commercial tetrode. Cryogenic tests will be carried out at LBNL to make use of their test facilities, cryogenics and laser systems, and for future use with beam. Demonstration of this new type of booster cryomodule will open many new applications of SRF linear accelerators.

Grimm, Terry L; Bogle, Andrew; Deimling, Brian; Hollister, Jerry; II, Randall Jecks; Kolka, Ahren; Romel, Chandra

2009-04-13T23:59:59.000Z

339

Advanced Light Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Next >> Next >> Visitors Access to the ALS Gate Access guest-house Guest House lab-shuttles Lab Shuttles maps-and-directions Maps and Directions Parking Safety Safety for Users safety-for-staff Safety for Staff In Case of Emergency Resources Acronyms Multimedia Employment staff-intranet Staff Intranet Site Map Contact Digg: ALSBerkeleyLab Facebook Page: 208064938929 Flickr: advancedlightsource Twitter: ALSBerkeleyLab YouTube: AdvancedLightSource January 2014 Sun Mon Tue Wed Thu Fri Sat 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Recent Science Highlights Minding the Gap Makes for More Efficient Solar Cells Using novel materials to develop thin, flexible, and more efficient photovoltaic cells is one of the hottest topics in current materials research. A class of transition metals undergo a dramatic change that makes them ideal for solar energy applications.

340

Constricted glow discharge plasma source  

SciTech Connect

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.

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

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Light Sources Directorate Strategic Plan  

NLE Websites -- All DOE Office Websites (Extended Search)

Light Sources Directorate Light Sources Directorate Strategic Plan December 2009 Light Sources Directorate Strategic Plan December 2009 ii | Vision and Mission Light Sources Directorate Strategic Plan The VISION of the Light Sources Directorate is: to be a provider of choice for world-class photon science and facilities that deliver outstanding scientific productivity and impact, and to be recognized as a leader in developing innovative techniques and ap- plications of photon science Our MISSION is defined by the set of activities that are required to realize this vision: to advance scientific knowledge and to solve critical problems through the design, construction, operation, and use of premier photon science facilities | Table of Contents Light Sources Directorate Strategic Plan

342

Optically pumped polarized ion sources  

SciTech Connect

Polarization transfer collisions between protons, atomic hydrogen, or deuterium and optically pumped alkali-metal vapour are implemented in the high current optically pumped polarized ion source (OPPIS) and the laser driven source (LDS) of nuclear polarized atoms for target applications. The OPPIS technique overcomes the limitations on intensity of the conventional atomic beam source technique and meets the requirements of the new generation of polarization experiments at multi-GeV accelerators and colliders. 17 refs., 3 figs.

Zelenski, A.N.

1995-12-31T23:59:59.000Z

343

ARC SNUBBERS NEUTRAL BEAM SOURCES  

E-Print Network (OSTI)

transformer cores near the source and route all of the powertransformer that transiently separates the energy in the capacitances of the power

Baker, W.R.

2011-01-01T23:59:59.000Z

344

Tsunami Information Sources: Part 3  

E-Print Network (OSTI)

A Landslide in the Upper Aleutian Forearc,' by G.J. Fryer,of the Source of the 1946 Aleutian 'Tsunami' Earthquake,"

Wiegel, Robert L.

2006-01-01T23:59:59.000Z

345

Video Library | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Archives APS Brochure Annual Reports Posters Podcasts Image Gallery external site Video Library Syndicated Feeds (RSS) Now Playing: The Advanced Photon Source More videos:...

346

Video Library | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (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...

347

Relative risks of energy sources  

Science Conference Proceedings (OSTI)

This paper compares the risks associated with various energy sources in an attempt to demonstrate the relative safety of nuclear energy. (JEF)

Haire, M.J.

1990-01-01T23:59:59.000Z

348

User Information | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

User Information The Advanced Photon Source provides a variety of guides, resources, and information for prospective, new, and current users. In this section: For Prospective Users...

349

Media Center | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

impact on nearly every aspect of our lives. Annual Reports Articles on Advanced Photon Source research and engineering highlights that are written for the interested...

350

Document Central | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

of Operations Manual APS QA Plan (obsolescence memo) APS Publications: APS Database APS Technical Publications Light Source Notes Technical Bulletins Safety Committee...

351

Information Technology | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Advanced Photon Source Information Technology Support Search APS ... Search Button About User Information News & Events Science & Education Beamlines Divisions Argonne Home >...

352

CAT Communicator | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Division XSD Groups Industry Argonne Home Advanced Photon Source News Archives CAT Communicator CAT Communicator was a newsletter intended to provide APS information to...

353

Organization Chart | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Source (APS) organization comprises three divisions and one project office. Accelerator Systems Division (ASD) ASD provides engineering and physics support for the APS, and...

354

The status of the spallation neutron source ion source  

SciTech Connect

The ion source for the spallation neutron source (SNS) is a radio-frequency, multicusp source designed to deliver 45 mA of H2 to the SNS accelerator with a pulse length of 1 ms and repetition rate of 60 Hz. A total of three ion sources have been fabricated and commissioned at Lawrence Berkeley National Laboratory and subsequently delivered to the SNS at the Oak Ridge National Laboratory. The ion sources are currently being rotated between operation on the SNS accelerator, where they are involved in ongoing efforts to commission the SNS LINAC, and the hot spare stand (HSS), where high-current tests are in progress. Commissioning work involves operating the source in a low duty-factor mode (pulse width {approx}200 ms and repetition rate {approx}5 Hz) for extended periods of time while the high-current tests involve source operation at full duty-factor of 6 percent (1 ms/60 Hz). This report discusses routine performance of the source employed in the commissioning role as well as the initial results o f high-current tests performed on the HSS.

Welton, R.F.; Stockli, M.P.; Murray, S.N.; Keller, R.

2003-09-11T23:59:59.000Z

355

Selecting quality sources: Bridging the gap between the perception and use of information sources  

Science Conference Proceedings (OSTI)

This study investigated undergraduatesâ?? source selection behaviour: what sources they use frequently, what criteria they consider important for source selection, how they perceive different sources, and whether their source selection behaviour ... Keywords: information literacy education, source evaluation criteria, source perception, source selection, source use, undergraduates

Kyung-Sun Kim; Sei-Ching Joanna Sin

2011-04-01T23:59:59.000Z

356

Alternative Energy Sources – Myths and Realities  

E-Print Network (OSTI)

Alternative Energy Sources - Myths and Realities Walterneed to think about alternative energy sources; the worlddepletion of oil? Alternative energy sources can be divided

Youngquist, Walter

1998-01-01T23:59:59.000Z

357

Alternative Energy Sources – Myths and Realities  

E-Print Network (OSTI)

Alternative Energy Sources Nonrenewable Renewable Oil sands,themselves. Summary Oil is a unique energy source that hasfor oil, which is the limitation many alternative sources

Youngquist, Walter

1998-01-01T23:59:59.000Z

358

4th Generation ECR Ion Sources  

E-Print Network (OSTI)

the 1980s. Second generation sources, which operate betweengenerations. First generation ECR sources operate between 5Two superconducting 3 rd generation ECR sources, VENUS and

Lyneis, Claude M.

2010-01-01T23:59:59.000Z

359

An Upgrade for the Advanced Light Source  

E-Print Network (OSTI)

of an optimized third generation source not only translatesfirst third-generation synchrotron light sources, the ALS,of a third-generation synchrotron light source translates

2004-01-01T23:59:59.000Z

360

Storage Rings for Science with: Electron-Positron Collisions, Hadron Collisions and Synchrotron Light  

SciTech Connect

The author is honored to receive the 2009 Robert Wilson Prize and the recognition that comes with it. The citation for the prize reads, 'For his outstanding contribution to the design and construction of accelerators that has led to the realization of major machines for fundamental science on two continents and his promotion of international collaboration.' In this article, he will discuss the two construction projects, which he led, one (TRISTAN e{sup +}e{sup -} Collider at KEK) in Japan and the other (RHIC at BNL) in the USA, covering project issues and lessons learned from these projects. Although both of them were built on separate continents, it is interesting to note that they are both built on long off-shore islands. He will also add comments on his recent engagement in the development of the Conceptual Design for the National Synchrotron Light Source II (NSLS-II).

Ozaki,S.

2009-05-04T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Storage Rings for Science with: Electron-Positron Collisions, Hadron Collisions and Synchrotron Light  

SciTech Connect

The author is honored to receive the 2009 Robert Wilson Prize and the recognition that comes with it. The citation for the prize reads, 'For his outstanding contribution to the design and construction of accelerators that has led to the realization of major machines for fundamental science on two continents and his promotion of international collaboration.' In this article, he will discuss the two construction projects, which he led, one (TRISTAN e{sup +}e{sup -} Collider at KEK) in Japan and the other (RHIC at BNL) in the USA, covering project issues and lessons learned from these projects. Although both of them were built on separate continents, it is interesting to note that they are both built on long off-shore islands. He will also add comments on his recent engagement in the development of the Conceptual Design for the National Synchrotron Light Source II (NSLS-II).

Ozaki,S.

2009-05-04T23:59:59.000Z

362

PET imaging of thin objects: measuring the effects of positron range and partial-volume averaging in the leag of Nicotiana Tabacum  

SciTech Connect

PET imaging in plants is receiving increased interest as a new strategy to measure plant responses to environmental stimuli and as a tool for phenotyping genetically engineered plants. PET imaging in plants, however, poses new challenges. In particular, the leaves of most plants are so thin that a large fraction of positrons emitted from PET isotopes ({sup 18}F, {sup 11}C, {sup 13}N) escape while even state-of-the-art PET cameras have significant partial-volume errors for such thin objects. Although these limitations are acknowledged by researchers, little data have been published on them. Here we measured the magnitude and distribution of escaping positrons from the leaf of Nicotiana tabacum for the radionuclides {sup 18}F, {sup 11}C and {sup 13}N using a commercial small-animal PET scanner. Imaging results were compared to radionuclide concentrations measured from dissection and counting and to a Monte Carlo simulation using GATE (Geant4 Application for Tomographic Emission). Simulated and experimentally determined escape fractions were consistent. The fractions of positrons (mean {+-} S.D.) escaping the leaf parenchyma were measured to be 59 {+-} 1.1%, 64 {+-} 4.4% and 67 {+-} 1.9% for {sup 18}F, {sup 11}C and {sup 13}N, respectively. Escape fractions were lower in thicker leaf areas like the midrib. Partial-volume averaging underestimated activity concentrations in the leaf blade by a factor of 10 to 15. The foregoing effects combine to yield PET images whose contrast does not reflect the actual activity concentrations. These errors can be largely corrected by integrating activity along the PET axis perpendicular to the leaf surface, including detection of escaped positrons, and calculating concentration using a measured leaf thickness.

Alexoff, D.L.; Alexoff, D.L.; Dewey, S.L.; Vaska, P.; Krishnamoorthy, S.; Ferrieri, R.; Schueller, M.; Schlyer, D.; Fowler, J.S.

2011-03-01T23:59:59.000Z

363

A system of beam energy measurement based on the Compton backscattered laser photons for the VEPP-2000 electron-positron collider  

E-Print Network (OSTI)

The beam energy measurement system for the VEPP-2000 electron-positron collider is described. The method of Compton backscattering of $CO$ laser photons on the electron beam is used. The relative systematic uncertainty of the beam energy determination is estimated as 6\\cdot10^{-5}. It was obtained through comparison of the results of the beam energy measurements using the Compton backscattering and resonance depolarization methods.

E. V. Abakumova; M. N. Achasov; D. E. Berkaev; V. V. Kaminsky; I. A. Koop; A. A. Korol; S. V. Koshuba; A. A. Krasnov; N. Yu. Muchnoi; E. A. Perevedentsev; E. E. Pyata; P. Yu. Shatunov; Yu. M. Shatunov; D. B. Shwartz

2013-10-29T23:59:59.000Z

364

A system of beam energy measurement based on the Compton backscattered laser photons for the VEPP-2000 electron-positron collider  

E-Print Network (OSTI)

The beam energy measurement system for the VEPP-2000 electron-positron collider is described. The method of Compton backscattering of $CO$ laser photons on the electron beam is used. The relative systematic uncertainty of the beam energy determination is estimated as 6\\cdot10^{-5}. It was obtained through comparison of the results of the beam energy measurements using the Compton backscattering and resonance depolarization methods.

Abakumova, E V; Berkaev, D E; Kaminsky, V V; Koop, I A; Korol, A A; Koshuba, S V; Krasnov, A A; Muchnoi, N Yu; Perevedentsev, E A; Pyata, E E; Shatunov, P Yu; Shatunov, Yu M; Shwartz, D B

2013-01-01T23:59:59.000Z

365

Hollow electrode plasma excitation source  

DOE Patents (OSTI)

A plasma source incorporates a furnace as a hollow anode, while a coaxial cathode is disposed therewithin. The source is located in a housing provided with an ionizable gas such that a glow discharge is produced between anode and cathode. Radiation or ionic emission from the glow discharge characterizes a sample placed within the furnace and heated to elevated temperatures.

Ballou, Nathan E. (West Richland, WA)

1992-01-01T23:59:59.000Z

366

Hollow electrode plasma excitation source  

DOE Patents (OSTI)

A plasma source incorporates a furnace as a hollow anode, while a coaxial cathode is disposed therewithin. The source is located in a housing provided with an ionizable gas such that a glow discharge is produced between anode and cathode. Radiation or ionic emission from the glow discharge characterizes a sample placed within the furnace and heated to elevated temperatures. 5 figs.

Ballou, N.E.

1992-04-14T23:59:59.000Z

367

Fourth Generation Light Source Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

The Workshop on Scientific Opportunities for Fourth Generation Light The Workshop on Scientific Opportunities for Fourth Generation Light Sources October 27 to 29, 1997 at the Advanced Photon Source at Argonne National Laboratory. This workshop is being co-hosted by APS, NSLS, SSRL and TJNAF. FGLSlogo This workshop will explore the phenomenology of interactions with ultra-high-power, -brilliance, and -coherence light sources in the DUV, soft x-ray, and x-ray regimes, as well as the scientific opportunities they provide. The workshop will begin with tutorials on the generation and properties of these sources and identify issues in their use in experimentation. Also included will be an overview of current efforts to develop these sources and a review of the scientific opportunities defined by previous research and workshops. These background talks will be followed

368

Measurement of the response of an SCG1-C scintillation glass shower detector to 2 to 17. 5 GeV positrons  

SciTech Connect

We have measured the response of an electromagnetic shower counter constructed from the new scintillation glass (SCG1-C, Ohara Optical Glass, Inc.) to positrons in the energy range 2 to 17.5 GeV. We have measured the energy resolution of this 18.4 radiation length detector plus its attendant SF5 lead glass shower counter array to be sigma/E = (1.64 +- 0.14)% + (1.13 +- 0.33)%/..sqrt..E with the constant term dominated by variations in the conversion point of the positron and shower leakage. We found this counter to be linear over the energy range examined. We have also measured the light output of the SCG1-C counter relative to light output of the SF5 lead glass guard blocks using 17.5 GeV positrons. We find that the SCG1-C counter produces 5.10 +- 0.30 more light at the phototube than the SF5 lead glass counters.

Cox, B.; Hale, G.; Mazur, P.O.

1982-10-01T23:59:59.000Z

369

Multi-source solar simulator using single light source  

DOE Patents (OSTI)

Methods, techniques and apparatus are described for adjusting the spectral irradiance characteristics of a light source. The invention is applicable to any light source and has many areas of utility. One example is for simulating solar light for use in testing efficiency of photovoltaic cells. Solar light at any point in the world can be simulated. Also, light having any desired wavelength (or combination of desired wavelengths) can be obtained from a single light source using the techniques and apparatus of the invention. 4 figs.

Emery, K.A.; Osterwald, C.R.

1989-08-17T23:59:59.000Z

370

Advanced Light Source Activity Report 2002  

E-Print Network (OSTI)

ALS and the Advanced Photon Source (APS). The LDLR crystals,Director for the Advanced Photon Source (APS), and Steven

Duque editor, Theresa; Greiner editor, Annette; Moxon editor, Elizabeth; Robinson editor, Arthur; Tamura editor, Lori

2003-01-01T23:59:59.000Z

371

Advanced Photon Source Industrial Liaison Office | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Industrial Liaison Office Industrial Liaison Office registration page New to Synchrotron Radiation New to the APS Already a User Advanced Photon Source Industrial Liaison Office APS Welcome to the Advanced Photon Source Welcome to the Advanced Photon Source (APS) at Argonne National Laboratory. We are one of five synchrotron radiation light sources operated as national user facilities by the U.S. Department of Energy's Office of Science. The APS is open to everyone who can utilize extremely bright x-ray photon beams for high-value research. This premier national research facility provides these x-ray beams to more than 5,000 scientists from all 50 United States, the District of Columbia, Puerto Rico, and several foreign countries. These scientists come to the APS from industry, universities,

372

International Data on Radiological Sources  

SciTech Connect

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.

Martha Finck; Margaret Goldberg

2010-07-01T23:59:59.000Z

373

Diversity employment and recruitment sources  

SciTech Connect

Effective human resources management has been identified as one of four critical success factors in the Department of Energy Strategic Plan. The Plan states relative to this factor: ``The Department seeks greater alignment of resources with agency priorities and increased diversification of the workforce, including gender, ethnicity, age, and skills. This diversification will bring new thinking and perspectives that heretofore have not had a voice in departmental decision-making.`` This Guide has been developed as a key tool to assist Department of Energy management and administrative staff in achieving Goal 2 of this critical success factor, which is to ``Ensure a diverse and talented workforce.`` There are numerous sources from which to recruit minorities, women and persons with disabilities. Applying creativity and proactive effort, using traditional and non-traditional approaches, and reaching out to various professional, academic and social communities will increase the reservoir of qualified candidates from which to make selections. In addition, outreach initiatives will undoubtedly yield further benefits such as a richer cultural understanding and diversity awareness. The resource listings presented in this Guide are offered to encourage active participation in the diversity recruitment process. This Guide contains resource listings by state for organizations in the following categories: (1) African American Recruitment Sources; (2) Asian American/Pacific Islander Recruitment Sources; (3) Hispanic Recruitment Sources; (4) Native American/Alaskan Native Recruitment Sources; (5) Persons with Disabilities Recruitment Sources; and (6) Women Recruitment Sources.

Not Available

1994-08-01T23:59:59.000Z

374

Intraoperative beta probe: A device for detecting tissue labeled with positron or electron emitting isotopes during surgery  

Science Conference Proceedings (OSTI)

An intraoperative beta probe was designed, built, and tested for detection of radio-labeled malignant tissues that has the advantage of being selectively sensitive to beta while insensitive to gamma radiation. Since beta radiation (electrons or positrons) has a short range in tissue, this probe is ideal for detecting tracers in tumors at the surface of the surgical field. This probe contains a plastic scintillation detector sensitive to beta rays and to a lesser degree some background gamma rays. A second detector counts spurious gamma rays and allows for their subtraction from the activity measured by the first detector. Sensitivity of the dual probe for I-131 and F-18 was measured to be 108 counts/s/kBq (4000 counts/s/[mu]Ci). The dual-detector probe faithfully measured the 10:1 tumor'' to background ratio of radioactivity concentrations in a simulated environment of a tumor in the presence of intense background 511 keV photons. In another phantom experiment, simulating abdominal tumor deposits with various realistic I-131 radioactive concentrations, the probe was able to accurately identify tumors of approximately 50 mg with a tumor/normal radioactivity concentration of 3/1 in 10 s.

Daghighian, F. (Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10021 (United States)); Mazziotta, J.C. (Division of Brain Mapping of Neuropsychiatric Institute, Department of Neurology, Department of Pharmacology, Department of Radiological Sciences, UCLA School of Medicine, Los Angeles, California 90024 (United States)); Hoffman, E.J. (Department of Pharmacology, Department of Radiological Sciences, UCLA School of Medicine, Los Angeles, California 90024 (United States)); Shenderov, P.; Eshaghian, B. (Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10021 (United States)); Siegel, S.; Phelps, M.E. (Department of Pharmacology, Department of Radiological Sciences, UCLA School of Medicine, Los Angeles, California 90024 (United States))

1994-01-01T23:59:59.000Z

375

2-Deoxy-2-[F-18]fluoro-D-glucose Joint Uptake on Positron Emission Tomography Images: Rheumatoid Arthritis Versus Osteoarthritis  

E-Print Network (OSTI)

Purpose: Previous positron emission tomography (PET) studies have shown increased 2-deoxy-2-[18F]fluoro-D-glucose (FDG) uptake in joints of patients with osteoarthritis (OA) and inflamed joints of patients with rheumatoid arthritis (RA). This study compares FDG uptake in joints of RA and OA patients and FDG-uptake with clinical signs of inflammation. Procedures: FDG-PET scans of hands and wrists were performed in patients with RA and primary OA. PET data were compared with clinical data. Results: 29 % of RA joints and 6 % of OA joints showed elevated FDG-uptake. The level of uptake in PET-positive OA joints was not significantly different from that in RA joints. The majority of PET results of RA joints corresponded with clinical findings. Clinical synovitis was found some OA joints with FDG-uptake. Conclusions: FDG-uptake was observed in the majority of clinically inflamed RA joints and in a few OA joints with no significant difference in uptake level. The latter may be due to secondary synovitis.

E. H. Elzinga; B. A. C. Dijkmans; A. E. Voskuyl

2007-01-01T23:59:59.000Z

376

Role of Positron Emission Tomography in the Treatment of Occult Disease in Head-and-Neck Cancer: A Modeling Approach  

SciTech Connect

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.

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

377

APS Upgrade | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Workshop on new science opportunities provided by a multi-bend achromat lattice at the APS APS-U MBA Lattice Workshop Registration is now closed. Please contact Diane Wilkinson ext. 7810 or a member of the Workshop Organizing Committee for changes or modifications to your registration. Submit Comments, Suggestions, and Ideas for MBA Lattice Workshop October 21-22 Advanced Photon Source Argonne National Lab The Advanced Photon Source Upgrade is focused on delivering a powerful, versatile facility for science using high-brightness, high-energy X-rays. At APS, and around the light source community, scientists have been developing storage ring designs that push closer to the ultimate diffraction limit for X-ray sources. A recent report by the Basic Energy Sciences Advisory Committee, which advises the Director of the U.S.

378

Navy Heat Source Safety Tests  

SciTech Connect

The purpose of these tests was to validate the integrity of the Navy Heat Source after imposing conditions which might, in the extreme, be encountered singly or serially so that safety would be assured.

Anderson, C. G.; Cartmill, W. B.

1975-06-18T23:59:59.000Z

379

Lesson 2: Energy Sources Overview  

E-Print Network (OSTI)

Lesson 2: Energy Sources #12;Overview · Most geologic disasters involve the release of large amounts of energy either quickly or slowly. To understand these processes, we need to know where the energy released was derived from. #12

Chen, Po

380

APS Upgrade | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Workshop on new science opportunities provided by a multi-bend achromat lattice at the APS October 21-22 Advanced Photon Source Argonne National Lab To prepare for the workshop...

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Next Generation Light Source Workshops  

NLE Websites -- All DOE Office Websites (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...

382

Quantum fields as gravitational sources  

E-Print Network (OSTI)

The practice of setting quantum fields as sources for classical general relativity is examined. Several conceptual problems are identified which invalidate apparently innocuous equations. Alternative ways to links classical general relativity with quantum theory using Bohm's theory are proposed.

Mark J Hadley

2008-08-13T23:59:59.000Z

383

H- radio frequency source development at the Spallation Neutron Source  

Science Conference Proceedings (OSTI)

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent {approx}38 mA peak current in the linac and an availability of {approx}90%. H{sup -} beam pulses ({approx}1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, {approx}60 kW) of a copper antenna that has been encased with a thickness of {approx}0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of {approx}99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of {approx}75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance/installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to {approx}100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

Welton, Robert F [ORNL; Pennisi, Terry R [ORNL; Roseberry, Ron T [ORNL; Stockli, Martin P [ORNL

2012-01-01T23:59:59.000Z

384

Photon stimulated desorption measurement of an extruded aluminum beam chamber for the Advanced Photon Source  

DOE Green Energy (OSTI)

The Advanced Photon Source (APS), presently being commisioned, will produce X-ray s of unprecedented brightness. The high energy ring of the APS is a 7 GeV positron storage ring, 1104 meters in circumference designed to operate at less than 10{sup {minus}9} Torr with 300 ma of beam and a greater than 10 hour lifetime. The storage ring vacuum chamber is constructed from an extruded 6063 aluminum alloy. During the construction phase, a 2.34 m long section of the APS extruded aluminum chamber was set up on National Synchrotron Light Source (NSLS) X-ray Beamlline X28A and Photon Stimulated Desorption (PSD) was measured. Cleaning and preparation of the chamber was identical to that of the APS construction. In addition to the chamber, small samples of M, Be, and Cu were also exposed to white light having a critical energy of 5 keV. In addition to PSD, measurements were made of specular and diffuse scattering of photons. The chamber and samples were each exposed to a dose greater than 10{sup 23} photons per meter. Desorption yields for H{sub 2}, CO, CO{sub 2}, CH{sub 4} and H{sub 2}0 are reported as a function of accumulated flux, critical energy, incidence angle, and preparation. These results are compared with previous results for aluminum on NSLS Beamlline U1OB and PSD results of other laboratories published for aluminum.

Foerster, C.L.; Lanni, C. [Brookhaven National Lab., Upton, NY (United States); Noonan, J.R.; Rosenberg, R.A. [Argonne National Lab., IL (United States)

1995-12-31T23:59:59.000Z

385

Automatic Quenching of High Energy gamma-ray Sources by Synchrotron Photons  

Science Conference Proceedings (OSTI)

Here we investigate evolution of a magnetized system, in which continuously produced high energy emission undergoes annihilation on a soft photon field, such that the synchrotron radiation of the created electron-positron pairs increases number density of the soft photons. This situation is important in high energy astrophysics, because, for an extremely wide range of magnetic field strengths (nano to mega Gauss), it involves {gamma}-ray photons with energies between 0.3GeV and 30TeV. We derive and analyze the conditions for which the system is unstable to runaway production of soft photons and ultrarelativistic electrons, and for which it can reach a steady state with an optical depth to photon-photon annihilation larger than unity, as well those for which efficient pair loading of the emitting volume takes place. We also discuss the application of our analysis to a realistic situation involving astrophysical sources of a broad-band {gamma}-ray emission and briefly consider the particular case of sources close to active supermassive black holes.

Stawarz, Lukasz; /KIPAC, Menlo Park /SLAC /Jagiellonian U., Astron. Observ.; Kirk, John; /Heidelberg, Max Planck Inst.

2007-02-02T23:59:59.000Z

386

rf improvements for Spallation Neutron Source H ion source  

Science Conference Proceedings (OSTI)

The Spallation Neutron Source at Oak Ridge National Laboratory is ramping up the accelerated proton beam power to 1.4 MW and just reached 1 MW. The rf-driven multicusp ion source that originates from the Lawrence Berkeley National Laboratory has been delivering 38 mA H beam in the linac at 60 Hz, 0.9 ms. To improve availability, a rf-driven external antenna multicusp ion source with a water-cooled ceramic aluminum nitride AlN plasma chamber is developed. Computer modeling and simulations have been made to analyze and optimize the rf performance of the new ion source. Operational statistics and test runs with up to 56 mA medium energy beam transport beam current identify the 2 MHz rf system as a limiting factor in the system availability and beam production. Plasma ignition system is under development by using a separate 13 MHz system. To improve the availability of the rf power system with easier maintenance, we tested a 70 kV isolation transformer for the 80 kW, 6% duty cycle 2 MHz amplifier to power the ion source from a grounded solid-state amplifier. 2010 American Institute of Physics.

Kang, Yoon W [ORNL; Fuja, Raymond E [ORNL; Goulding, Richard Howell [ORNL; Hardek, Thomas W [ORNL; Lee, Sung-Woo [ORNL; McCarthy, Mike [ORNL; Piller, Chip [ORNL; Shin, Ki [ORNL; Stockli, Martin P [ORNL; Welton, Robert F [ORNL

2010-01-01T23:59:59.000Z

387

Multilevel cascade voltage source inverter with seperate DC sources  

SciTech Connect

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.

Peng, Fang Zheng (Oak Ridge, TN); Lai, Jih-Sheng (Knoxville, TN)

1997-01-01T23:59:59.000Z

388

Multilevel cascade voltage source inverter with seperate DC sources  

DOE Patents (OSTI)

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.

Peng, Fang Zheng (Knoxville, TN); Lai, Jih-Sheng (Blacksburg, VA)

2002-01-01T23:59:59.000Z

389

Multilevel cascade voltage source inverter with separate DC sources  

DOE Patents (OSTI)

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.

Peng, F.Z.; Lai, J.S.

1997-06-24T23:59:59.000Z

390

Design and Prototyping of the AMD for the ILC  

NLE Websites -- All DOE Office Websites (Extended Search)

flux concentrator to generate the strong magnetic field. By varying the inner shape of a flux concentrator, one can shape the on-axis magnetic field profile of the AMD....

391

Development of Vertically Integrated Circuits for ILC Vertex Detectors  

E-Print Network (OSTI)

We report on studies of vertically interconnected electronics (3D) performed by the Fermilab pixel group over the past two years. These studies include exploration of interconnect technology, backside thinning and laser annealing, the production of the first 3D chip for particle physics, the VIP, and plans for a commercial two-tier 3D fabrication run.

Ronald Lipton; for the Fermilab Pixel R&D Group

2009-01-29T23:59:59.000Z

392

Development of Vertically Integrated Circuits for ILC Vertex Detectors  

E-Print Network (OSTI)

We report on studies of vertically interconnected electronics (3D) performed by the Fermilab pixel group over the past two years. These studies include exploration of interconnect technology, backside thinning and laser annealing, the production of the first 3D chip for particle physics, the VIP, and plans for a commercial two-tier 3D fabrication run.

Lipton, Ronald

2009-01-01T23:59:59.000Z

393

Configuration Studies and Recommendations for the ILC Damping Rings  

E-Print Network (OSTI)

supercon- ducting device, the power consumption is primarilypower consumption of a normal-conducting electromagnetic device,power consumption for a normal-conducting elec- tromagnetic device,

Wolski, Andrzej; Gao, Jie; Guiducci, Susanna

2006-01-01T23:59:59.000Z

394

Research on fusion neutron sources  

SciTech Connect

The use of fusion devices as powerful neutron sources has been discussed for decades. Whereas the successful route to a commercial fusion power reactor demands steady state stable operation combined with the high efficiency required to make electricity production economic, the alternative approach to advancing the use of fusion is free of many of complications connected with the requirements for economic power generation and uses the already achieved knowledge of Fusion physics and developed Fusion technologies. 'Fusion for Neutrons' (F4N), has now been re-visited, inspired by recent progress achieved on comparably compact fusion devices, based on the Spherical Tokamak (ST) concept. Freed from the requirement to produce much more electricity than used to drive it, a fusion neutron source could be efficiently used for many commercial applications, and also to support the goal of producing energy by nuclear power. The possibility to use a small or medium size ST as a powerful or intense steady-state fusion neutron source (FNS) is discussed in this paper in comparison with the use of traditional high aspect ratio tokamaks. An overview of various conceptual designs of compact fusion neutron sources based on the ST concept is given and they are compared with a recently proposed Super Compact Fusion Neutron Source (SCFNS), with major radius as low as 0.5 metres but still able to produce several MW of neutrons in a steady-state regime.

Gryaznevich, M. P. [Tokamak Solutions UK, Culham Science Centre, Abingdon, OXON, OX133DB (United Kingdom)

2012-06-19T23:59:59.000Z

395

Positron emission mammography (PEM): Effect of activity concentration, object size, and object contrast on phantom lesion detection  

Science Conference Proceedings (OSTI)

Purpose: To characterize the relationship between lesion detection sensitivity and injected activity as a function of lesion size and contrast on the PEM (positron emission mammography) Flex Solo II scanner using phantom experiments. Methods: Phantom lesions (spheres 4, 8, 12, 16, and 20 mm diameter) were randomly located in uniform background. Sphere activity concentrations were 3 to 21 times the background activity concentration (BGc). BGc was a surrogate for injected activity; BGc ranged from 0.44-4.1 kBq/mL, corresponding to 46-400 MBq injections. Seven radiologists read 108 images containing zero, one, or two spheres. Readers used a 5-point confidence scale to score the presence of spheres. Results: Sensitivity was 100% for lesions {>=}12 mm under all conditions except for one 12 mm sphere with the lowest contrast and lowest BGc (60% sensitivity). Sensitivity was 100% for 8 mm spheres when either contrast or BGc was high, and 100% for 4 mm spheres only when both contrast and BGc were highest. Sphere contrast recovery coefficients (CRC) were 49%, 34%, 26%, 14%, and 2.8% for the largest to smallest spheres. Cumulative specificity was 98%. Conclusions: Phantom lesion detection sensitivity depends more on sphere size and contrast than on BGc. Detection sensitivity remained {>=}90% for injected activities as low as 100 MBq, for lesions {>=}8 mm. Low CRC in 4 mm objects results in moderate detection sensitivity even for 400 MBq injected activity, making it impractical to optimize injected activity for such lesions. Low CRC indicates that when lesions <8 mm are observed on PEM images they are highly tracer avid with greater potential of clinical significance. High specificity (98%) suggests that image statistical noise does not lead to false positive findings. These results apply to the 85 mm thick object used to obtain them; lesion detectability should be better (worse) for thinner (thicker) objects based on the reduced (increased) influence of photon attenuation.

MacDonald, Lawrence R.; Wang, Carolyn L.; Eissa, Marna; Haseley, David; Kelly, Mary M.; Liu, Franklin; Parikh, Jay R.; Beatty, J. David; Rogers, James V. [Department of Radiology, University of Washington, 1959 NE Pacific Street, Box 357987, Seattle, Washington 98195 (United States); Department of Radiology, University of Washington, 1959 NE Pacific Street, Box 357987, Seattle, Washington 98195 and Swedish Cancer Institute, Swedish Medical Center, 1221 Madison Street Arnold Pavilion, Seattle, Washington 98104 (United States); Swedish Cancer Institute, Swedish Medical Center, 1221 Madison Street Arnold Pavilion, Seattle, Washington 98104 (United States); Department of Radiology, University of Washington, 1959 NE Pacific Street, Box 357987, Seattle, Washington 98195 (United States); Swedish Cancer Institute, Swedish Medical Center, 1221 Madison Street Arnold Pavilion, Seattle, Washington 98104 (United States)

2012-10-15T23:59:59.000Z

396

Determination of Internal Target Volume From a Single Positron Emission Tomography/Computed Tomography Scan in Lung Cancer  

SciTech Connect

Purpose: The use of four-dimensional computed tomography (4D-CT) to determine the tumor internal target volume (ITV) is usually characterized by high patient radiation exposure. The objective of this study was to propose and evaluate an approach that relies on a single static positron emission tomography (PET)/CT scan to determine the ITV, thereby eliminating the need for 4D-CT and thus reduce patient radiation dose. Methods and Materials: The proposed approach is based on the concept that the observed PET image is the result of a joint convolution of an ideal PET image (free from motion and partial volume effect) with a motion-blurring kernel (MBK) and partial volume effect. In this regard, the MBK and tumor ITV are then estimated from the deconvolution of this joint model. To test this technique, phantom and patient studies were performed using different sphere/tumor sizes and motion trajectories. In all studies, a 4D-CT and a PET/CT image of the sphere/tumor were acquired. The ITV from the proposed technique was then compared to the maximum intensity projection (MIP) volume of the 4D-CT images. A Dice coefficient of the two volumes was calculated to represent the similarity between the two ITVs. Results: The average ITVs of the proposed technique were 97.2% {+-} 0.3% and 81.0% {+-} 16.7% similar to the MIP volume in the phantom and patient studies, respectively. The average dice coefficients were 0.87 {+-} 0.05 and 0.73 {+-} 0.16, respectively, for the two studies. Conclusion: Using the proposed approach, a single static PET/CT scan has the potential to replace a 4D-CT to determine the tumor ITV. This approach has the added advantage of reducing patient radiation exposure and determining the tumor MBK compared to 4D-CT/MIP-CT.

Chang Guoping; Chang Tingting [Department of Electrical and Computer Engineering, Rice University, Houston, Texas (United States); Pan Tinsu [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Clark, John W. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas (United States); Mawlawi, Osama R., E-mail: OMawlawi@mdanderson.org [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2012-05-01T23:59:59.000Z

397

SNS | Spallation Neutron Source | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

SNS SNS Instruments Working with SNS Contact Us User Program Manager Laura Morris Edwards 865.574.2966 Spallation Neutron Source Home | User Facilities | SNS SNS | Spallation Neutron Source SHARE SNS is an accelerator-based neutron source in Oak Ridge, Tennessee, USA. This one-of-a-kind facility provides the most intense pulsed neutron beams in the world for scientific research and industrial development. The 80-acre SNS site is located on Chestnut Ridge and is part of Oak Ridge National Laboratory. Although most people don't know it, neutron scattering research has a lot to do with our everyday lives. For example, things like medicine, food, electronics, and cars and airplanes have all been improved by neutron scattering research. Neutron research also helps scientists improve materials used in a

398

Blind Source Separation Techniques for  

E-Print Network (OSTI)

Blind Source Separation techniques, based both on Independent Component Analysis and on second order statistics, are presented and compared for extracting partially hidden texts and textures in document images. Barely perceivable features may occur, for instance, in ancient documents previously erased and then re-written (palimpsests), or for transparency or seeping of ink from the reverse side, or from watermarks in the paper. Detecting these features can be of great importance to scholars and historians. In our approach, the document is modeled as the superposition of a number of source patterns, and a simplified linear mixture model is introduced for describing the relationship between these sources and multispectral views of the document itself. The problem of detecting the patterns that are barely perceivable in the visible color image is thus formulated as the one of separating the various patterns in the mixtures. Some examples from an extensive experimentation with real ancient documents are shown and commented.

Detecting Hidden Texts; Anna Tonazzini; Emanuele Salerno; Matteo Mochi; Luigi Bedini

2004-01-01T23:59:59.000Z

399

Video Library | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Media Center: Media Center: Calendar of Events APS News User News Article Archives APS Brochure Annual Reports Posters Podcasts Image Gallery external site Video Library Syndicated Feeds (RSS) Featured Videos: Introduction to the Advanced Photon Source The Advanced Photon Source An introduction and overview of the technology that produces the brightest x-ray beams in the Western Hemisphere, and the research carried out by scientists using those x-rays. Timelapse of the APS construction Building the APS A timelapse video from 1990-1995 that shows the Advanced Photon Source rising from an empty field to become the site of a national synchrotron x-ray research facility. Physics of the Blues Physics of the Blues In looking at commonalities between music and science, former PSC Director

400

Energy Sources | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Energy Sources Energy Sources Energy Sources December 12, 2013 AEMC Summit Slideshow: Innovation in the Manufacturing Sector Learn how advanced technologies are helping manufacturers reduce waste, increase productivity and become leaders in the clean energy economy. October 16, 2013 West Penn Power SEF Commercial Loan Program The West Penn Power Sustainable Energy Fund (WPPSEF) promotes the use of renewable energy and clean energy among commercial, industrial, institutional and residential customers in the West Penn market region. Eligible technologies include solar, wind, low-impact hydro, and sustainable biomass such as closed-loop biomass and biomass gasification, as well as energy efficiency. October 16, 2013 UES - Renewable Energy Credit Purchase Program '''''Note: The Arizona Corporation Commission (ACC) is in the process of

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

E Source | Open Energy Information  

Open Energy Info (EERE)

Source Source Jump to: navigation, search Name E Source Address 1965 North 57th Court Place Boulder, CO Zip 80301 Product Research firm Year founded 1986 Number of employees 51-200 Phone number 303.345.9000 Website [www.esource.com www.esource.com ] Coordinates 40.01895°, -105.2207964° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.01895,"lon":-105.2207964,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

402

Compact portable electric power sources  

DOE Green Energy (OSTI)

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.

Fry, D.N.; Holcomb, D.E.; Munro, J.K.; Oakes, L.C.; Matson, M.J.

1997-02-01T23:59:59.000Z

403

Miniature x-ray source  

DOE Patents (OSTI)

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.

Trebes, James E. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA)

2000-01-01T23:59:59.000Z

404

Miniature x-ray source  

DOE Patents (OSTI)

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.

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

405

Low-pressure ion source  

DOE Patents (OSTI)

A low pressure ion source for a neutron source comprises a filament cathode and an anode ring. Approximately 150V is applied between the cathode and the anode. Other electrodes, including a heat shield, a reflector and an aperture plate with a focus electrode, are placed at intermediate potentials. Electrons from the filament drawn out by the plasma and eventually removed by the anode are contained in a magnetic field created by a magnet ring. Ions are formed by electron impact with deuterium or tritium and are extracted at the aperture in the focus electrode. The ion source will typically generate a 200 mA beam through a 1.25 cm/sup 2/ aperture for an arc current of 10A. For deuterium gas, the ion beam is over 50 percent D/sup +/ with less than 1% impurity. The current density profile across the aperture will typically be uniform to within 20%.

Bacon, F.M.; Brainard, J.P.; O' Hagan, J.B.; Walko, R.J.

1982-10-27T23:59:59.000Z

406

Sensor/source electrometer circuit  

DOE Patents (OSTI)

A multiple decade electrometer circuit is claimed which can measure low input currents or act as a current source and is comprised of a microprocessor controlled digital to analog converters to derive individual decades. A plurality of decades are created by multiple D-A voltage sources which generate electrometer currents through scaled resistors. After a first series of decades of current are successively produced, the converters are 10 cycled to generate current through new resistors scaled to produce another series decades of current. In this manner, the electrometer circuit generates or senses a plurality of decades of current without significant scale change.

Hughes, W.J.

1991-12-31T23:59:59.000Z

407

Advanced Light Source Activity Report 2005  

E-Print Network (OSTI)

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

Tamura Ed., Lori S.

2010-01-01T23:59:59.000Z

408

A global sourcing strategy for durable tooling  

E-Print Network (OSTI)

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 ...

Vasovski, Steven

2006-01-01T23:59:59.000Z

409

Comment on the article 'Solitary waves and double layers in an ultra-relativistic degenerate dusty electron-positron-ion plasma'[Phys. Plasmas 19, 033705 (2012)  

SciTech Connect

More recently, Roy et al.[Phys. Plasmas 19, 033705 (2012)] have investigated the occurrence of nonlinear solitary and double-layers in an ultrarelativistic dusty electron-positron-ion degenerate plasma using a Sagdeev potential method. They have considered a full parametric examination on Mach-number criteria for existence of such nonlinear excitations using the specific degeneracy limits of Chandrasekhar equation of state (EoS) for Fermi-Dirac plasmas. In this comment, we point-out a misleading extension of polytropic EoS to study the Fermi-Dirac relativistically degenerate plasmas.

Akbari-Moghanjoughi, M. [Department of Physics, Faculty of Sciences, Azarbaijan University of Tarbiat Moallem, 51745-406 Tabriz (Iran, Islamic Republic of)

2012-06-15T23:59:59.000Z

410

MBA-SourceProperties.pptx  

NLE Websites -- All DOE Office Websites (Extended Search)

source change my x-ray beam Jonathan L ang Advanced P hoton S ource APS Upgrade - MBA Lattice * What i s e mi7ance? * I d on't n eed a s mall b eam a ll t he me ( the b eam w...

411

BrightSource Energy | Open Energy Information  

Open Energy Info (EERE)

BrightSource Energy Jump to: navigation, search Name BrightSource Energy Place Oakland, California Zip 94612 Sector Solar Product California-based company that develops, builds,...

412

WEB RESOURCE: Magnesium Welding - Information Sources for ...  

Science Conference Proceedings (OSTI)

Sep 20, 2007 ... This web-based, magnesium welding resource is a compilation of: ... SOURCE: “ Magnesium Welding – Information Sources for Magnesium ...

413

Diversity Employment and Recruitment Sources | Department of...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Diversity Employment and Recruitment Sources Diversity Employment and Recruitment Sources Guide to resources for diversity employment DERSG.PDF Description Diversity Employment and...

414

Calibrations of Electronic Brachytherapy Sources, Traceable ...  

Science Conference Proceedings (OSTI)

... As in traditional brachytherapy, the source is placed ... established to provide calibrations of these sources. ... through use of a primary-standard free-air ...

2010-10-05T23:59:59.000Z

415

Miniaturized cathodic arc plasma source  

DOE Patents (OSTI)

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.

Anders, Andre (Albany, CA); MacGill, Robert A. (Richmond, CA)

2003-04-15T23:59:59.000Z

416

Spallation Neutron Source The Spallation Neutron Source (SNS)  

NLE Websites -- All DOE Office Websites (Extended Search)

F/gim F/gim Spallation Neutron Source The Spallation Neutron Source (SNS) gives researchers more detailed informa- tion on the structure and dynamics of physical and biological materials than ever before possible. This accelerator- based facility provides the most intense pulsed neutron beams in the world. Scien- tists are able to count scattered neutrons, measure their energies and the angles at which they scatter, and map their final positions. SNS enables measurements of greater sensitivity, higher speed, higher resolution, and in more complex sample environments than have been possible at existing neutron facilities. Future Growth SNS was designed from the outset to accommodate a second target station, effectively doubling the capacity of the

417

Intensity Modulated Radiation Therapy Dose Painting for Localized Prostate Cancer Using {sup 11}C-choline Positron Emission Tomography Scans  

Science Conference Proceedings (OSTI)

Purpose: To demonstrate the technical feasibility of intensity modulated radiation therapy (IMRT) dose painting using {sup 11}C-choline positron emission tomography PET scans in patients with localized prostate cancer. Methods and Materials: This was an RT planning study of 8 patients with prostate cancer who had {sup 11}C-choline PET scans prior to radical prostatectomy. Two contours were semiautomatically generated on the basis of the PET scans for each patient: 60% and 70% of the maximum standardized uptake values (SUV{sub 60%} and SUV{sub 70%}). Three IMRT plans were generated for each patient: PLAN{sub 78}, which consisted of whole-prostate radiation therapy to 78 Gy; PLAN{sub 78-90}, which consisted of whole-prostate RT to 78 Gy, a boost to the SUV{sub 60%} to 84 Gy, and a further boost to the SUV{sub 70%} to 90 Gy; and PLAN{sub 72-90}, which consisted of whole-prostate RT to 72 Gy, a boost to the SUV{sub 60%} to 84 Gy, and a further boost to the SUV{sub 70%} to 90 Gy. The feasibility of these plans was judged by their ability to reach prescription doses while adhering to published dose constraints. Tumor control probabilities based on PET scan-defined volumes (TCP{sub PET}) and on prostatectomy-defined volumes (TCP{sub path}), and rectal normal tissue complication probabilities (NTCP) were compared between the plans. Results: All plans for all patients reached prescription doses while adhering to dose constraints. TCP{sub PET} values for PLAN{sub 78}, PLAN{sub 78-90}, and PLAN{sub 72-90} were 65%, 97%, and 96%, respectively. TCP{sub path} values were 71%, 97%, and 89%, respectively. Both PLAN{sub 78-90} and PLAN{sub 72-90} had significantly higher TCP{sub PET} (P=.002 and .001) and TCP{sub path} (P<.001 and .014) values than PLAN{sub 78}. PLAN{sub 78-90} and PLAN{sub 72-90} were not significantly different in terms of TCP{sub PET} or TCP{sub path}. There were no significant differences in rectal NTCPs between the 3 plans. Conclusions: IMRT dose painting for localized prostate cancer using {sup 11}C-choline PET scans is technically feasible. Dose painting results in higher TCPs without higher NTCPs.

Chang, Joe H. [Radiation Oncology Centre, Austin Health, Victoria (Australia) [Radiation Oncology Centre, Austin Health, Victoria (Australia); University of Melbourne, Victoria (Australia); Lim Joon, Daryl [Radiation Oncology Centre, Austin Health, Victoria (Australia)] [Radiation Oncology Centre, Austin Health, Victoria (Australia); Lee, Sze Ting [University of Melbourne, Victoria (Australia) [University of Melbourne, Victoria (Australia); Centre for PET, Austin Health, Victoria (Australia); Ludwig Institute for Cancer Research, Victoria (Australia); Gong, Sylvia J. [Centre for PET, Austin Health, Victoria (Australia)] [Centre for PET, Austin Health, Victoria (Australia); Anderson, Nigel J. [Radiation Oncology Centre, Austin Health, Victoria (Australia)] [Radiation Oncology Centre, Austin Health, Victoria (Australia); Scott, Andrew M. [University of Melbourne, Victoria (Australia) [University of Melbourne, Victoria (Australia); Centre for PET, Austin Health, Victoria (Australia); Ludwig Institute for Cancer Research, Victoria (Australia); Davis, Ian D. [University of Melbourne, Victoria (Australia) [University of Melbourne, Victoria (Australia); Ludwig Institute for Cancer Research, Victoria (Australia); Clouston, David [Focus Pathology, Victoria (Australia)] [Focus Pathology, Victoria (Australia); Bolton, Damien [University of Melbourne, Victoria (Australia) [University of Melbourne, Victoria (Australia); Department of Urology, Austin Health, Victoria (Australia); Hamilton, Christopher S. [Radiation Oncology Centre, Austin Health, Victoria (Australia)] [Radiation Oncology Centre, Austin Health, Victoria (Australia); Khoo, Vincent, E-mail: vincent.khoo@rmh.nhs.uk [Radiation Oncology Centre, Austin Health, Victoria (Australia) [Radiation Oncology Centre, Austin Health, Victoria (Australia); University of Melbourne, Victoria (Australia); Department of Clinical Oncology, Royal Marsden Hospital and Institute of Cancer Research, London (United Kingdom)

2012-08-01T23:59:59.000Z

418

Positron Emission Tomography for Assessing Local Failure After Stereotactic Body Radiotherapy for Non-Small-Cell Lung Cancer  

Science Conference Proceedings (OSTI)

Purpose: We analyzed whether positron emission tomography (PET)/computed tomography standardized uptake values (SUVs) after stereotactic body radiotherapy (SBRT) could predict local recurrence (LR) in non-small-cell lung cancer (NSCLC). Methods and Materials: This study comprised 128 patients with Stage I (n = 68) or isolated recurrent/secondary parenchymal (n = 60) NSCLC treated with image-guided SBRT to 50 Gy over 4 consecutive days; prior radiotherapy was allowed. PET/computed tomography scans were obtained before therapy and at 1 to 6 months after therapy, as well as subsequently as clinically indicated. Continuous variables were analyzed with Kruskal-Wallis tests and categorical variables with Pearson chi-square or Fisher exact tests. Actuarial local failure rates were calculated with the Kaplan-Meier method. Results: At a median follow-up of 31 months (range, 6-71 months), the actuarial 1-, 2-, and 3-year local control rates were 100%, 98.5%, and 98.5%, respectively, in the Stage I group and 95.8%, 87.6%, and 85.8%, respectively, in the recurrent group. The cumulative rates of regional nodal recurrence and distant metastasis were 8.8% (6 of 68) and 14.7% (10 of 68), respectively, for the Stage I group and 11.7% (7 of 60) and 16.7% (10 of 60), respectively, for the recurrent group. Univariate analysis showed that SUVs obtained 12.1 to 24 months after treatment for the Stage I group (p = 0.007) and 6.1 to 12 months and 12.1 to 24 months after treatment for the recurrent group were associated with LR (p < 0.001 for both). Of the 128 patients, 17 (13.3%) had ipsilateral consolidation after SBRT but no elevated metabolic activity on PET; none had LR. The cutoff maximum SUV of 5 was found to have 100% sensitivity, 91% specificity, a 50% positive predictive value, and a 100% negative predictive value for predicting LR. Conclusions: PET was helpful for distinguishing SBRT-induced consolidation from LR. SUVs obtained more than 6 months after SBRT for NSCLC were associated with local failure. A maximum SUV greater than 5, especially at more than 6 months after SBRT, should prompt biopsy to rule out LR.

Zhang Xu; Liu Hui [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States)] [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Balter, Peter [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Allen, Pamela K.; Komaki, Ritsuko [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States)] [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Pan, Tinsu [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States)] [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Chuang, Hubert H. [Department of Nuclear Medicine, University of Texas MD Anderson Cancer Center, Houston, TX (United States)] [Department of Nuclear Medicine, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Chang, Joe Y., E-mail: jychang@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States)

2012-08-01T23:59:59.000Z

419

Outcomes of Positron Emission Tomography-Staged Clinical N3 Breast Cancer Treated With Neoadjuvant Chemotherapy, Surgery, and Radiotherapy  

SciTech Connect

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.

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

420

Pretreatment Staging Positron Emission Tomography/Computed Tomography in Patients With Inflammatory Breast Cancer Influences Radiation Treatment Field Designs  

SciTech Connect

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.

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

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421

Precision measurement of charged pion and kaon differential cross sections in electron-positron annihilation at Q = 10.52 GeV  

E-Print Network (OSTI)

Measurements of inclusive differential cross sections for charged pion and kaon production in electron-positron annihilation have been carried out at a center-of-mass energy of Q = 10.52 GeV. The measurements were performed with the Belle detector at the KEKB electron-positron collider using a data sample containing 113 million e+e- -> qqbar events, where q={u,d,s,c}. We present charge-integrated differential cross sections d\\sigma_h+-/dz for h+- = pi+-, K+- as a function of the relative hadron energy z = 2*E_h / sqrt{s} from 0.2 to 0.98. The combined statistical and systematic uncertainties for pi+- (K+-) are 4% (4%) at z ~ 0.6 and 15% (24%) at z ~ 0.9. The cross sections are the first measurements of the z-dependence of pion and kaon production for z > 0.7 as well as the first precision cross section measurements at a center-of-mass energy far below the Z^0 resonance used by the experiments at LEP and SLC.

Belle Collaboration; M. Leitgab; R. Seidl; M. Grosse Perdekamp; A. Vossen; I. Adachi; H. Aihara; D. M. Asner; V. Aulchenko; T. Aushev; A. M. Bakich; B. Bhuyan; A. Bondar; A. Bozek; M. Bra?ko; J. Brodzicka; T. E. Browder; V. Chekelian; A. Chen; P. Chen; B. G. Cheon; K. Chilikin; K. Cho; V. Chobanova; Y. Choi; D. Cinabro; J. Dalseno; Z. Drásal; D. Dutta; S. Eidelman; D. Epifanov; H. Farhat; J. E. Fast; V. Gaur; N. Gabyshev; R. Gillard; F. Giordano; Y. M. Goh; B. Golob; J. Haba; K. Hayasaka; H. Hayashii; Y. Hoshi; W. -S. Hou; Y. B. Hsiung; H. J. Hyun; T. Iijima; A. Ishikawa; R. Itoh; W. W. Jacobs; T. Julius; J. H. Kang; P. Kapusta; E. Kato; T. Kawasaki; H. J. Kim; H. O. Kim; J. B. Kim; J. H. Kim; M. J. Kim; J. Klucar; B. R. Ko; P. Kodyš; R. T. Kouzes; P. Križan; P. Krokovny; R. Kumar; T. Kumita; Y. -J. Kwon; J. S. Lange; S. -H. Lee; Y. Li; Z. Q. Liu; D. Liventsev; D. Matvienko; K. Miyabayashi; H. Miyata; R. Mizuk; A. Moll; N. Muramatsu; E. Nakano; M. Nakao; Z. Natkaniec; M. Nayak; E. Nedelkovska; C. Ng; N. Nellikunnummel; O. Nitoh; A. Ogawa; S. Ogawa; T. Ohshima; S. Okuno; S. L. Olsen; C. Oswald; P. Pakhlov; H. Park; H. K. Park; T. K. Pedlar; R. Pestotnik; M. Petri?; L. E. Piilonen; M. Röhrken; H. Sahoo; Y. Sakai; S. Sandilya; L. Santelj; T. Sanuki; Y. Sato; O. Schneider; G. Schnell; C. Schwanda; K. Senyo; O. Seon; M. E. Sevior; M. Shapkin; C. P. Shen; T. -A. Shibata; J. -G. Shiu; B. Shwartz; A. Sibidanov; F. Simon; P. Smerkol; Y. -S. Sohn; A. Sokolov; E. Solovieva; M. Stari?; M. Sumihama; T. Sumiyoshi; G. Tatishvili; Y. Teramoto; T. Tsuboyama; M. Uchida; T. Uglov; Y. Unno; S. Uno; Y. Usov; C. Van Hulse; G. Varner; V. Vorobyev; M. N. Wagner; C. H. Wang; J. Wang; M. -Z. Wang; P. Wang; M. Watanabe; Y. Watanabe; K. M. Williams; E. Won; Y. Yamashita; V. Zhilich; V. Zhulanov

2013-01-25T23:59:59.000Z

422

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)

A handling and processing apparatus 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.

Ferrieri, Richard A. (Patchogue, NY); Schlyer, David J. (Bellport, NY); Alexoff, David (Westhampton, NY)

1996-01-09T23:59:59.000Z

423

Next Generation Light Source Workshops  

NLE Websites -- All DOE Office Websites (Extended Search)

Next Generation Light Source Workshops 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 scientific needs into the technical performance requirements. Feedback from these workshops will provide important input for advancing the design of the facility. Workshops are planned in the following areas Fundamental Atomic, Molecular, Optical Physics & Combustion Dynamics Mon. Aug. 20 - Tues. Aug 21, 2012 Physical Chemistry, Catalysis, & Photosynthesis Thurs. Aug. 23 - Fri. Aug 24, 2012 Quantum Materials, Magnetism & Spin Dynamics Mon. Aug. 27 - Tues. Aug 28, 2012 Materials & Bio-imaging at the Nanoscale Thurs. Aug. 30 - Fri. Aug 31, 2012 Further information is available on the workshop website:

424

X-ray lithography source  

SciTech Connect

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.

Piestrup, Melvin A. (Woodside, CA); Boyers, David G. (Mountain View, CA); Pincus, Cary (Sunnyvale, CA)

1991-01-01T23:59:59.000Z

425

A voltage controlled current source  

DOE Patents (OSTI)

A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoampers to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

Casne, G.M.

1990-12-21T23:59:59.000Z

426

X-ray lithography source  

DOE Patents (OSTI)

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.

Piestrup, M.A.; Boyers, D.G.; Pincus, C.

1991-12-31T23:59:59.000Z

427

Increased security through open source  

E-Print Network (OSTI)

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.

Jaap-Henk Hoepman; Bart Jacobs

2008-01-25T23:59:59.000Z

428

ION SOURCE FOR A CALUTRON  

DOE Patents (OSTI)

This patent relates to ion sources and more particularly describes an ion source for a calutron which has the advantage of efficient production of an ion beam and long operation time without recharging. The source comprises an arc block provided with an arc chamber connected to a plurality of series-connected charge chambers and means for heating the charge within the chambers. A cathode is disposed at one end of the arc chamber and enclosed hy a vapor tight housing to protect the cathode. The arc discharge is set up between the cathode and the block due to a difference in potentials placed on these parts, and a magnetic field is aligned with the arc discharge. Cooling of the arc block is accomplished by passing coolant through a hollow stem secured at one end to the block and rotatably mounted at the other end through the wall of the calutron. The ions are removed through a slit in the arc chamber by accelerating electrodes.

Backus, J.G.

1957-12-24T23:59:59.000Z

429

Source control strategy accelerates remediation  

SciTech Connect

Shallow land burial of ion-level radioactive wastes at ORNL has resulted in the release of contaminants into surrounding soil, groundwater, and surface water. Multiple contaminated areas occurring in close proximity make it difficult to relate contaminant releases to a specific site. To address this issue, similar and contiguous contaminated sites within the same drainage area have been combined into Waste Area Groupings. These Waste Area Groupings were prioritized and became the focus of the Comprehensive Environmental Response, Compensation, and Liability Act remediation process. Since the majority of the groupings are in the White Oak Creek drainage basin, the remediation strategy is to control contaminant releases from these source areas first, followed by remediation of White Oak Creek. In planning the remediation program, it became clear that until the issues of ultimate land use and institutional control, waste treatment technologies, and waste disposal facilities are resolved, final remediation objectives cannot be defined and remedial alternatives cannot be evaluated. Consequently, instead of postponing remedial actions until these issues are resolved, a strategy to control the sources of contaminant release with a serie s of interim actions was developed. In the near term, this strategy reduces off-site risk by eliminating contaminant releases and controls on-site risk through institutional control. Source control will allow time to achieve consensus on long-term institutional control and land use issues to develop appropriate treatment technologies, and to construct the necessary disposal facilities without further environmental degradation.

Garland, S.B. II [Oak Ridge National Lab., TN (United States); Hammond, R. [Environmental Protection Agency, Atlanta, GA (United States). Region IV

1993-06-01T23:59:59.000Z

430

National Synchrotron Light Source Activity Report 1998  

Science Conference Proceedings (OSTI)

National Synchrotron Light Source Activity Report for period October 1, 1997 through September 30, 1998

Rothman, Eva

1999-05-01T23:59:59.000Z

431

Electron Positron Factories  

E-Print Network (OSTI)

is dictated by the voltage requirement. Assuming similar HOMrequirement is reduced by about one The choice of frequency and voltagethe power requirement. scaies as so reducing the voltage is

Zisman, Michael S.

2011-01-01T23:59:59.000Z

432

Electron Positron Factories  

E-Print Network (OSTI)

see Table I), gives where VRF is in MV, fRF is in MHz, andClL of 0.5 cm (requiring VRF = 80 MV) would permit Ib :::::mm can be produced with VRF = 27 MV. Now the power de'lsity

Zisman, Michael S.

2011-01-01T23:59:59.000Z

433

Compact x-ray source and panel  

SciTech Connect

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.

Sampayon, Stephen E. (Manteca, CA)

2008-02-12T23:59:59.000Z

434

The Advanced Light Source Upgrade  

SciTech Connect

The ALS, a third-generation synchrotron light source at Berkeley Lab, has been operating for almost a decade and is generating forefront science by exploiting the high brightness of a third-generation source in three areas: (1) high resolving power for spectroscopy; (2) high spatial resolution for microscopy and spectromicroscopy; and (3) high coherence for experiments such as speckle. However, the ALS was one of the first third-generation machines to be designed, and accelerator and insertion-device technology have significantly changed since its conception. As a result, its performance will inevitably be outstripped by newer, more advanced sources. To remain competitive and then set a new standard, the performance of the ALS, in particular its brightness, must be enhanced. Substantial improvements in brightness and current have always been feasible in principle, but they incur the penalty of a much reduced lifetime, which is totally unacceptable to our users. Significant brightness improvements can be realized in the core soft x-ray region by going to top-off operation, where injection would be quasi-continuous and the lifetime objections disappear. In top-off mode with higher average current, a reduced vertical emittance and beta function, and small-gap permanent-magnet or superconducting insertion devices, one to two orders of magnitude improvement in brightness can be had in the soft x-ray range. These improvements also extend the high energy range of the undulator radiation beyond the current limit of 2000 eV. Descriptions of the upgrade and the important new science achievable are presented.

Chemla, Daniel S.; Feinberg, Benjamin; Hussain, Zahid; Krebs, Gary F.; Padmore, Howard A.; Robin, David S.; Robinson, Arthur L.; Smith, Neville V.

2003-11-04T23:59:59.000Z

435

Pennsylvania Source Term Tracking System  

SciTech Connect

The Pennsylvania Source Term Tracking System tabulates surveys received from radioactive waste generators in the Commonwealth of radioactive waste is collected each quarter from generators using the Low-Level Radioactive Waste Management Quarterly Report Form (hereafter called the survey) and then entered into the tracking system data base. This personal computer-based tracking system can generate 12 types of tracking reports. The first four sections of this reference manual supply complete instructions for installing and setting up the tracking system on a PC. Section 5 presents instructions for entering quarterly survey data, and Section 6 discusses generating reports. The appendix includes samples of each report.

1992-08-01T23:59:59.000Z

436

Detecting fission from special nuclear material sources  

DOE Patents (OSTI)

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.

Rowland, Mark S. (Alamo, CA); Snyderman, Neal J. (Berkeley, CA)

2012-06-05T23:59:59.000Z

437

Blind source separation with dynamic source number using adaptive neural algorithm  

Science Conference Proceedings (OSTI)

A difficult blind source separation (BSS) issue dealing with an unknown and dynamic number of sources is tackled in this study. In the past, the majority of BSS algorithms familiarize themselves with situations where the numbers of sources are given, ... Keywords: Adaptive learning rate, Adaptive neural algorithm, Blind source separation, Dynamic number of sources

Tsung-Ying Sun; Chan-Cheng Liu; Shang-Jeng Tsai; Sheng-Ta Hsieh

2009-07-01T23:59:59.000Z

438

Thulium heat sources for space power applications  

DOE Green Energy (OSTI)

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.

Alderman, C.J.

1992-05-01T23:59:59.000Z

439

Positron Emission Tomography/Computed Tomography-Guided Intensity-Modulated Radiotherapy for Limited-Stage Small-Cell Lung Cancer  

Science Conference Proceedings (OSTI)

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.

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

440

Image Source Separation Using Color Channel Dependencies  

Science Conference Proceedings (OSTI)

We investigate the problem of source separation in images in the Bayesian framework using the color channel dependencies. As a case in point we consider the source separation of color images which have dependence between its components. A Markov Random ...

Koray Kayabol; Ercan E. Kuruoglu; Bulent Sankur

2009-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Problems with packaged sources in foreign countries  

SciTech Connect

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.

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

442

Air Permitting for Stationary Sources (New Hampshire)  

Energy.gov (U.S. Department of Energy (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...

443

Total cost model for making sourcing decisions  

E-Print Network (OSTI)

This thesis develops a total cost model based on the work done during a six month internship with ABB. In order to help ABB better focus on low cost country sourcing, a total cost model was developed for sourcing decisions. ...

Morita, Mark, M.B.A. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

444

Agri Source Fuels | Open Energy Information  

Open Energy Info (EERE)

Agri-Source Fuels Place Pensacola, Florida Zip 32505 Product Biodiesel producer located in Florida that owns a plant in Dade City. References Agri-Source Fuels1 LinkedIn...

445

Characterizations and Diagnostics of Compton Light Source.  

E-Print Network (OSTI)

?? The High Intensity Gamma-ray Source (HIGS) at Duke University is a world class Compton light source facility. At the HIGS, a Free-Electron Laser (FEL)… (more)

Sun, Changchun

2009-01-01T23:59:59.000Z

446

" Row: NAICS Codes; Column: Energy Sources...  

U.S. Energy Information Administration (EIA) Indexed Site

and",,"Coke and"," ","of Energy Sources","Row" "Code(a)","Subsector and Industry","Source(b)","Electricity(c)","Fuel Oil","Fuel Oil(d)","Gas(e)","NGL(f)","Coal","...

447

" Row: NAICS Codes; Column: Energy Sources...  

U.S. Energy Information Administration (EIA) Indexed Site

sidual","Distillate",,"LPG and",,"Coke and",,"of Energy Sources" "Code(a)","Subsector and Industry","Source(b)","Electricity(c)","Fuel Oil","Fuel Oil(d)","Natural...

448

Open Source Software Update | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Open Source Software Update Open Source Software Update CCBY932011.pdf DrewDEAR Data clauses for Software.pdf More Documents & Publications Part 2, Clauses Prescribed in DEAR...

449

Querying partially sound and complete data sources  

Science Conference Proceedings (OSTI)

When gathering data from multiple data sources, users need uniform, transparent access to data. Also, when extracting data from several independent, often only partially sound and complete data sources, it is useful to present users with meta-information ...

Alberto O. Mendelzon; George A. Mihaila

2001-05-01T23:59:59.000Z

450

NGLS: Next Generation Light Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Lab masthead Berkeley Lab A-Z Index Phone Book Careers Search DOE logo Lab masthead Berkeley Lab A-Z Index Phone Book Careers Search DOE logo NGLS logo NGLS Science NGLS Technology Seminars Workshop/Reports Related Links Further Info NGLS Facility Combustion Photosynthesis Photosynthesis Photosynthesis Today is a golden age for light sources. Storage ring-based synchrotrons routinely provide X-ray beams exploited by thousands of scientists annually to answer fundamental questions in diverse fields including human health, energy, and electronics and information processing. MORE > NGLS Science Science section chart NGLS CD-0 Proposal NGLS Technology Technology section chart Seminars Science section chart Workshops Science section chart Last updated 06/21/2013 Top A U.S. Department of Energy National Laboratory Operated by the University

451

Advanced Neutron Source enrichment study  

SciTech Connect

A study has been performed of the impact on performance of using low enriched uranium (20% {sup 235}U) or medium enriched uranium (35% {sup 235}U) as an alternative fuel for the Advanced Neutron Source, which is currently designed to use uranium enriched to 93% {sup 235}U. Higher fuel densities and larger volume cores were evaluated at the lower enrichments in terms of impact on neutron flux, safety, safeguards, technical feasibility, and cost. The feasibility of fabricating uranium silicide fuel at increasing material density was specifically addressed by a panel of international experts on research reactor fuels. The most viable alternative designs for the reactor at lower enrichments were identified and discussed. Several sensitivity analyses were performed to gain an understanding of the performance of the reactor at parametric values of power, fuel density, core volume, and enrichment that were interpolations between the boundary values imposed on the study or extrapolations from known technology.

Bari, R.A.; Ludewig, H.; Weeks, J.R.

1994-12-31T23:59:59.000Z

452

Energy Sources | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

July 20, 2011 July 20, 2011 Today's Forecast: Improved Wind Predictions Accurate weather forecasts are critical for making energy sources -- including wind and solar -- dependable and predictable. July 8, 2011 Energy Matters Mailbag This edition of the mailbag tackles follow-up questions from our Energy Matters discussion on breaking our reliance on foreign oil. June 30, 2011 Energy Matters: Our Energy Independence June 22, 2011 Distributed Energy Distributed energy consists of a range of smaller-scale and modular devices designed to provide electricity, and sometimes also thermal energy, in locations close to consumers. They include fossil and renewable energy technologies (e.g., photovoltaic arrays, wind turbines, microturbines, reciprocating engines, fuel cells, combustion turbines, and steam

453

APS News | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

APS News Archives: APS News Archives: 2012 | 2011 | 2010 | 2009 2008 | 2007 | 2006 | 2005 2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed APS News Kim of ASD Awarded 2014 Wilson Prize for Achievement in Physics of Particle Accelerators Kim of ASD Awarded 2014 Wilson Prize for Achievement in Physics of Particle Accelerators January 7, 2014 Kwang-Je Kim of the Advanced Photon Source has been named the recipient of the 2014 Robert R. Wilson Prize for Achievement in the Physics of Particle Accelerators, Harkay of ASD Elected to Fellowship in the American Physical Society Harkay of ASD Elected to Fellowship in the American Physical Society December 18, 2013 Katherine Harkay of the Accelerator Systems Division has been elected to Fellowship in the American Physical Society for

454

Safety Around Sources of Radiation  

NLE Websites -- All DOE Office Websites (Extended Search)

Keeping Exposure Low Keeping Exposure Low Working Safely Around Radioactive Contamination Types of Radiation Exposure Managing Radiation Emergencies Procedure Demonstration Is it safe to be around sources? Too much radiation exposure is harmful. The degree of radiation injury depends on the amount of radiation received and the time involved. In general, the higher the amount, the greater the severity of early effects (occurring within a few weeks) and the greater the possibility of late effects such as cancer. The BEIR V (Biological Effects of Ionizing Radiation) Committee of the National Research Council estimates that among 100,000 people exposed to a one-time dose of 10 rem (10,000 mrem) and followed over their life span, about 790 more would die of cancer than the estimated 20,000 cancer deaths that would be expected among a non-exposed group of the same size. NOTE: 10 rem = 100 millisieverts (100 mSv).

455

Detectors (XSD) | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

APS Detector Pool (X-ray Science Division) The Detector Pool provides many different types of x-ray detectors to beamline scientists at the Advanced Photon Source. These detectors are made available for short term loans (typically several days to a week or two, but this is flexible). The detector pool also coordinates loans between sectors, helps sectors repair equipment, and coordinates group purchases. Depending on budgets, we purchase new equipment, based largely on suggestions from the beamline scientists. Requests for detectors are submitted by beamline scientists at the sectors on behalf of general users. General Users are free to contact us regarding detector capabilities and other questions. The Detector Pool is staffed during normal working hours,

456

Energy Sources | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Renewable Energy Pilot Program Renewable Energy Pilot Program In June 2010, the Louisiana Public Service Commission (LPSC) unanimously approved a Renewable Energy Pilot Program for the state. The final implementation plan was adopted in November 2010. The goal of the pilot program is to determine whether a renewable portfolio standard is suitable for Louisiana. The pilot program has two major components: the Research Component and the Request for Proposal (RFP) Component. October 16, 2013 Renewable Energy Goal In May 2010, Oklahoma established a renewable energy goal for electric utilities operating in the state. The goal calls for 15% of the total installed generation capacity in Oklahoma to be derived from renewable sources by 2015. There are no interim targets, and the goal does not extend

457

Solenoid and monocusp ion source  

DOE Patents (OSTI)

An ion source which generates ions having high atomic purity incorporates a solenoidal magnetic field 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.

Brainard, J.P.; Burns, E.J.T.; Draper, C.H.

1995-12-31T23:59:59.000Z

458

Dosimetric Characteristics for Brachytherapy Sources  

SciTech Connect

Brachytherapy sources are characterized by the dosimetric parameters in a protocol such as the American Association of Physicists in Medicine Task Group 43. The air-kerma strength is measured and traceable to a primary standard. Then the parameters such as dose-rate constant, radial dose function, and anisotropy function are measured and related back to the primary standard. This is normally accomplished with thermoluminescent dosimeters (TLDs). Since radial dose function and anisotropy function are relative parameters, some of the dosimetric corrections are negligible. For the dose-rate constant, parameters such as the energy dependence compared with a calibration beam such as {sup 60}Co need to be accounted for. A description of the primary standard measurements and TLD measurements will be discussed.

DeWerd, Larry A.; Davis, Stephen D. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin (United States)

2011-05-05T23:59:59.000Z

459

MATERIALS FOR SPALLATION NEUTRON SOURCES: II: Radiation ...  

Science Conference Proceedings (OSTI)

MATERIALS FOR SPALLATION NEUTRON SOURCES: Session II: Radiation Effects, B. Sponsored by: Jt. SMD/MSD Nuclear Materials Committee Program ...

460

UK Radioactive Waste: Classification, Sources and Management ...  

Science Conference Proceedings (OSTI)

Paper contents outlook: Introduction; Radioactive waste classification; Sources of waste (Nuclear power plant operation/decommissioning, Reprocessing and ...

Note: This page contains sample records for the topic "ilc positron source" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We e