National Library of Energy BETA

Sample records for linear particle accelerator

  1. Equilibrium Orbit And Linear Oscillations Of Charged particles In axisymmetric E X B Fields And Application To Electron Ring accelerator

    E-Print Network [OSTI]

    Reiser, M

    1973-01-01

    Equilibrium Orbit And Linear Oscillations Of Charged particles In axisymmetric E X B Fields And Application To Electron Ring accelerator

  2. Linear induction accelerator

    DOE Patents [OSTI]

    Buttram, M.T.; Ginn, J.W.

    1988-06-21

    A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.

  3. Accelerating Particles with Plasma

    SciTech Connect (OSTI)

    Litos, Michael; Hogan, Mark

    2014-11-05

    Researchers at SLAC explain how they use plasma wakefields to accelerate bunches of electrons to very high energies over only a short distance. Their experiments offer a possible path for the future of particle accelerators.

  4. Charged particle accelerator grating

    DOE Patents [OSTI]

    Palmer, Robert B. (Shoreham, NY)

    1986-01-01

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  5. PARTICLE ACCELERATORS; ACCELERATORS; BEAM DUMPS; BENDING; CHANNELING...

    Office of Scientific and Technical Information (OSTI)

    Channeling through Bent Crystals Mack, Stephanie; Ottawa U. SLAC 43 PARTICLE ACCELERATORS; ACCELERATORS; BEAM DUMPS; BENDING; CHANNELING; CRYSTAL LATTICES; DETECTION; FORTRAN;...

  6. Non-Linear Transmission Line (NLTL) Microwave Source Lecture Notes the United States Particle Accelerator School

    SciTech Connect (OSTI)

    Russell, Steven J.; Carlsten, Bruce E.

    2012-06-26

    We will quickly go through the history of the non-linear transmission lines (NLTLs). We will describe how they work, how they are modeled and how they are designed. Note that the field of high power, NLTL microwave sources is still under development, so this is just a snap shot of their current state. Topics discussed are: (1) Introduction to solitons and the KdV equation; (2) The lumped element non-linear transmission line; (3) Solution of the KdV equation; (4) Non-linear transmission lines at microwave frequencies; (5) Numerical methods for NLTL analysis; (6) Unipolar versus bipolar input; (7) High power NLTL pioneers; (8) Resistive versus reactive load; (9) Non-lineaer dielectrics; and (10) Effect of losses.

  7. Charged particle accelerator grating

    DOE Patents [OSTI]

    Palmer, R.B.

    1985-09-09

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator is described. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams onto the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  8. Cast dielectric composite linear accelerator

    DOE Patents [OSTI]

    Sanders, David M. (Livermore, CA); Sampayan, Stephen (Manteca, CA); Slenes, Kirk (Albuquerque, NM); Stoller, H. M. (Albuquerque, NM)

    2009-11-10

    A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.

  9. A Novel Approach to Non linear Shock Acceleration

    E-Print Network [OSTI]

    Pasquale Blasi

    2001-11-28

    First order Fermi acceleration at astrophysical shocks is often invoked as a mechanism for the generation of non-thermal particles. This mechanism is especially simple in the approximation that the accelerated particles behave like test particles, not affecting the shocked fluid. Many complications enter the calculations when the accelerated particles have a backreaction on the fluid, in which case we may enter the non linear regime of shock acceleration. In this paper we summarize the main features of a semi-analytical approach to the study of the non linearity in shock acceleration, and compare some of the results with previous attempts and with the output of numerical simulations.

  10. Radio frequency focused interdigital linear accelerator

    DOE Patents [OSTI]

    Swenson, Donald A.; Starling, W. Joel

    2006-08-29

    An interdigital (Wideroe) linear accelerator employing drift tubes, and associated support stems that couple to both the longitudinal and support stem electromagnetic fields of the linac, creating rf quadrupole fields along the axis of the linac to provide transverse focusing for the particle beam. Each drift tube comprises two separate electrodes operating at different electrical potentials as determined by cavity rf fields. Each electrode supports two fingers, pointing towards the opposite end of the drift tube, forming a four-finger geometry that produces an rf quadrupole field distribution along its axis. The fundamental periodicity of the structure is equal to one half of the particle wavelength .beta..lamda., where .beta. is the particle velocity in units of the velocity of light and .lamda. is the free space wavelength of the rf. Particles are accelerated in the gaps between drift tubes. The particle beam is focused in regions inside the drift tubes.

  11. Linear accelerator for radioisotope production

    SciTech Connect (OSTI)

    Hansborough, L.D.; Hamm, R.W.; Stovall, J.E.

    1982-02-01

    A 200- to 500-..mu..A source of 70- to 90-MeV protons would be a valuable asset to the nuclear medicine program. A linear accelerator (linac) can achieve this performance, and it can be extended to even higher energies and currents. Variable energy and current options are available. A 70-MeV linac is described, based on recent innovations in linear accelerator technology; it would be 27.3 m long and cost approx. $6 million. By operating the radio-frequency (rf) power system at a level necessary to produce a 500-..mu..A beam current, the cost of power deposited in the radioisotope-production target is comparable with existing cyclotrons. If the rf-power system is operated at full power, the same accelerator is capable of producing an 1140-..mu..A beam, and the cost per beam watt on the target is less than half that of comparable cyclotrons.

  12. Seismic response of linear accelerators

    E-Print Network [OSTI]

    Collette, C; Guinchard, M; Hauviller, C

    2010-01-01

    This paper is divided into two parts. The first part presents recent measurements of ground motion in the LHC tunnel at CERN. From these measurements, an update of the ground motion model currently used in accelerator simulations is presented. It contains new features like a model of the lateral motion and the technical noise. In the second part, it is shown how this model can be used to evaluate the seismic response of a linear accelerator in the frequency domain. Then, the approach is validated numerically on a regular lattice, taking the dynamic behavior of the machine alignment stage and the mechanical stabilization of the quadrupoles into account.

  13. High field gradient particle accelerator

    DOE Patents [OSTI]

    Nation, John A. (Ithaca, NY); Greenwald, Shlomo (Haifa, IL)

    1989-01-01

    A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle.

  14. Ultra-high vacuum photoelectron linear accelerator

    DOE Patents [OSTI]

    Yu, David U.L.; Luo, Yan

    2013-07-16

    An rf linear accelerator for producing an electron beam. The outer wall of the rf cavity of said linear accelerator being perforated to allow gas inside said rf cavity to flow to a pressure chamber surrounding said rf cavity and having means of ultra high vacuum pumping of the cathode of said rf linear accelerator. Said rf linear accelerator is used to accelerate polarized or unpolarized electrons produced by a photocathode, or to accelerate thermally heated electrons produced by a thermionic cathode, or to accelerate rf heated field emission electrons produced by a field emission cathode.

  15. Particle Acceleration in Astrophysical Sources

    E-Print Network [OSTI]

    Amato, Elena

    2015-01-01

    Astrophysical sources are extremely efficient accelerators. Some sources emit photons up to multi-TeV energies, a signature of the presence, within them, of particles with energies much higher than those achievable with the largest accelerators on Earth. Even more compelling evidence comes from the study of Cosmic Rays, charged relativistic particles that reach the Earth with incredibly high energies: at the highest energy end of their spectrum, these subatomic particles are carrying a macroscopic energy, up to a few Joules. Here I will address the best candidate sources and mechanisms as cosmic particle accelerators. I will mainly focus on Galactic sources such as Supernova Remnants and Pulsar Wind Nebulae, which being close and bright, are the best studied among astrophysical accelerators. These sources are held responsible for most of the energy that is put in relativistic particles in the Universe, but they are not thought to accelerate particles up to the highest individual energies, $\\approx 10^{20}$ eV...

  16. The design and performance of a water cooling system for a prototype coupled cavity linear particle accelerator for the spallation neutron source

    SciTech Connect (OSTI)

    Bernardin, J. D. (John D.); Ammerman, C. N. (Curtt N.); Hopkins, S. M. (Steve M.)

    2002-01-01

    The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. The SNS will generate and employ neutrons as a research tool in a variety of disciplines including biology, material science, superconductivity, chemistry, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of, in part, a multi-cell copper structure termed a coupled cavity linac (CCL). The CCL is responsible for accelerating the protons from an energy of 87 MeV, to 185 MeV. Acceleration of the charged protons is achieved by the use of large electrical field gradients established within specially designed contoured cavities of the CCL. While a large amount of the electrical energy is used to accelerate the protons, approximately 60-80% of this electrical energy is dissipated in the CCL's copper structure. To maintain an acceptable operating temperature, as well as minimize thermal stresses and maintain desired contours of the accelerator cavities, the electrical waste heat must be removed from the CCL structure. This is done using specially designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by a complex water cooling and temperature control system. This paper discusses the design, analysis, and testing of a water cooling system for a prototype CCL. First, the design concept and method of water temperature control is discussed. Second, the layout of the prototype water cooling system, including the selection of plumbing components, instrumentation, as well as controller hardware and software is presented. Next, the development of a numerical network model used to size the pump, heat exchanger, and plumbing equipment, is discussed. Finally, empirical pressure, flow rate, and temperature data from the prototype CCL water cooling tests are used to assess water cooling system performance and numerical modeling accuracy.

  17. Voltage regulation in linear induction accelerators

    DOE Patents [OSTI]

    Parsons, W.M.

    1992-12-29

    Improvement in voltage regulation in a linear induction accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core is disclosed. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance. 4 figs.

  18. Voltage regulation in linear induction accelerators

    DOE Patents [OSTI]

    Parsons, William M. (Santa Fe, NM)

    1992-01-01

    Improvement in voltage regulation in a Linear Induction Accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance.

  19. The Stanford Mark III linear accelerator and speculations concerning the multi-Bev applications of electron linear accelerators

    E-Print Network [OSTI]

    Neal, R B

    1956-01-01

    The Stanford Mark III linear accelerator and speculations concerning the multi-Bev applications of electron linear accelerators

  20. Terahertz-driven linear electron acceleration

    E-Print Network [OSTI]

    Nanni, Emilio Alessandro; Ravi, Koustuban; Fallahi, Arya; Moriena, Gustavo; Miller, R J Dwayne; Kärtner, Franz X

    2014-01-01

    The cost, size and availability of electron accelerators is dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency (RF) accelerating structures operate with 30-50 MeV/m gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional RF structures. However, laser-driven electron accelerators require intense sources and suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here, we demonstrate the first linear acceleration of electrons with keV energy gain using optically-generated terahertz (THz) pulses. THz-driven accelerating structures enable high-gradient electron accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. Increasing the operational frequency of accelerators into the THz band allows for greatly increased accelerating ...

  1. Cosmic Particle Acceleration: Basic Issues

    E-Print Network [OSTI]

    T. W. Jones

    2000-12-22

    Cosmic-rays are ubiquitous, but their origins are surprisingly difficult to understand. A review is presented of some of the basic issues common to cosmic particle accelerators and arguments leading to the likely importance of diffusive shock acceleration as a general explanation. The basic theory of diffusive shock acceleration is outlined, followed by a discussion of some of the key issues that still prevent us from a full understanding of its outcomes. Some recent insights are mentioned at the end that may help direct ultimate resolution of our uncertainties.

  2. Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

    DOE Patents [OSTI]

    Maschke, A.W.

    1984-04-16

    A charged particle accelerating assembly provided with a predetermined ratio of parametric structural characteristics and with related operating voltages applied to each of its linearly spaced focusing and accelerating quadrupoles, thereby to maintain a particle beam traversing the electrostatic fields of the quadrupoles in the assembly in an essentially laminar flow through the assembly.

  3. Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

    DOE Patents [OSTI]

    Maschke, Alfred W. (East Moriches, NY)

    1985-01-01

    A charged particle accelerating assembly provided with a predetermined ratio of parametric structural characteristics and with related operating voltages applied to each of its linearly spaced focusing and accelerating quadrupoles, thereby to maintain a particle beam traversing the electrostatic fields of the quadrupoles in the assembly in an essentially laminar flow throughout the assembly.

  4. How Particle Accelerators Work | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    cancer patients. The vast majority of these irradiations are now performed with microwave linear accelerators producing electron beams and x-rays. Accelerator technology,...

  5. Cooled particle accelerator target

    DOE Patents [OSTI]

    Degtiarenko, Pavel V.

    2005-06-14

    A novel particle beam target comprising: a rotating target disc mounted on a retainer and thermally coupled to a first array of spaced-apart parallel plate fins that extend radially inwardly from the retainer and mesh without physical contact with a second array of spaced-apart parallel plate fins that extend radially outwardly from and are thermally coupled to a cooling mechanism capable of removing heat from said second array of spaced-apart fins and located within the first array of spaced-apart parallel fins. Radiant thermal exchange between the two arrays of parallel plate fins provides removal of heat from the rotating disc. A method of cooling the rotating target is also described.

  6. Naked singularities as particle accelerators

    E-Print Network [OSTI]

    Mandar Patil; Pankaj S. Joshi

    2010-11-25

    We investigate here the particle acceleration by naked singularities to arbitrarily high center of mass energies. Recently it has been suggested that black holes could be used as particle accelerators to probe the Planck scale physics. We show that the naked singularities serve the same purpose and probably would do better than their black hole counterparts. We focus on the scenario of a self-similar gravitational collapse starting from a regular initial data, leading to the formation of a globally naked singularity. It is seen that when particles moving along timelike geodesics interact and collide near the Cauchy horizon, the energy of collision in the center of mass frame will be arbitrarily high, thus offering a window to Planck scale physics.

  7. Naked singularities as particle accelerators

    SciTech Connect (OSTI)

    Patil, Mandar; Joshi, Pankaj S.

    2010-11-15

    We investigate here the particle acceleration by naked singularities to arbitrarily high center of mass energies. Recently it has been suggested that black holes could be used as particle accelerators to probe the Planck scale physics. We show that the naked singularities serve the same purpose and probably would do better than their black hole counterparts. We focus on the scenario of a self-similar gravitational collapse starting from a regular initial data, leading to the formation of a globally naked singularity. It is seen that when particles moving along timelike geodesics interact and collide near the Cauchy horizon, the energy of collision in the center of mass frame will be arbitrarily high, thus offering a window to Planck scale physics.

  8. 2010 Annual Planning Summary for Stanford Linear Accelerator...

    Energy Savers [EERE]

    0 Annual Planning Summary for Stanford Linear Accelerator Center Site Office (SLAC) 2010 Annual Planning Summary for Stanford Linear Accelerator Center Site Office (SLAC) Annual...

  9. STANFORD LINEAR ACCELERATOR CENTER Winter 1999, Vol. 29, No. 3

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    STANFORD LINEAR ACCELERATOR CENTER Winter 1999, Vol. 29, No. 3 #12;The Beam Line is published GEORGE TRILLING, KARL VAN BIBBER HERMAN WINICK Illustrations TERRY ANDERSON Distribution CRYSTAL TILGHMAN A PERIODICAL OF PARTICLE PHYSICS WINTER 1999 VOL. 29, NUMBER 3 Printed on recycled paper FEATURES 2 GOLDEN

  10. Relativistic Shocks: Particle Acceleration and Magnetization

    E-Print Network [OSTI]

    Sironi, Lorenzo; Lemoine, Martin

    2015-01-01

    We review the physics of relativistic shocks, which are often invoked as the sources of non-thermal particles in pulsar wind nebulae (PWNe), gamma-ray bursts (GRBs), and active galactic nuclei (AGN) jets, and as possible sources of ultra-high energy cosmic-rays. We focus on particle acceleration and magnetic field generation, and describe the recent progress in the field driven by theory advances and by the rapid development of particle-in-cell (PIC) simulations. In weakly magnetized or quasi parallel-shocks (where the magnetic field is nearly aligned with the flow), particle acceleration is efficient. The accelerated particles stream ahead of the shock, where they generate strong magnetic waves which in turn scatter the particles back and forth across the shock, mediating their acceleration. In contrast, in strongly magnetized quasi-perpendicular shocks, the efficiencies of both particle acceleration and magnetic field generation are suppressed. Particle acceleration, when efficient, modifies the turbulence ...

  11. Linear Accelerator | Advanced Photon Source

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousand CubicResourcelogo and-E C H2015Tray and|Projects PagesLinear

  12. Microwaves and particle accelerators: a fundamental link

    SciTech Connect (OSTI)

    Chattopadhyay, Swapan [Universities of Lancaster, Liverpool and Manchester and Cockcroft Institute, Cheshire (United Kingdom)

    2011-07-01

    John Cockcroft's splitting of the atom and Ernest Lawrence's invention of the cyclotron in the first half of the twentieth century ushered in the grand era of ever higher energy particle accelerators to probe deeper into matter. It also forged a link, bonding scientific discovery with technological innovation that continues today in the twenty first century. The development of radar and high power vacuum electronics, especially microwave power tubes like the magnetrons and the klystrons in the pre-second world war era, was instrumental in the rapid development of circular and linear charged particle accelerators in the second half of the twentieth century. We had harnessed the powerful microwave radio-frequency sources from few tens of MHz to up to 90 GHz spanning L-band to W-band frequencies. Simultaneously in the second half of the twentieth century, lasers began to offer very first opportunities of controlling charged particles at smaller resolutions on the scale of wavelengths of visible light. We also witnessed in this period the emergence of the photon and neutron sciences driven by accelerators built-by-design producing tailored and ultra-bright pulses of bright photons and neutrons to probe structure and function of matter from aggregate to individual molecular and atomic scales in unexplored territories in material and life sciences. As we enter the twenty first century, the race for ever higher energies, brightness and luminosity to probe atto-metric and atto-second domains of the ultra-small structures and ultra-fast processes continues. These developments depend crucially on yet further advancements in the production and control of high power and high frequency microwaves and light sources, often intricately coupled in their operation to the high energy beams themselves. We give a glimpse of the recent developments and innovations in the electromagnetic production and control of charged particle beams in the service of science and society. (author)

  13. RFQ device for accelerating particles

    DOE Patents [OSTI]

    Shepard, K.W.; Delayen, J.R.

    1995-06-06

    A superconducting radio frequency quadrupole (RFQ) device includes four spaced elongated, linear, tubular rods disposed parallel to a charged particle beam axis, with each rod supported by two spaced tubular posts oriented radially with respect to the beam axis. The rod and post geometry of the device has four-fold rotation symmetry, lowers the frequency of the quadrupole mode below that of the dipole mode, and provides large dipole-quadrupole mode isolation to accommodate a range of mechanical tolerances. The simplicity of the geometry of the structure, which can be formed by joining eight simple T-sections, provides a high degree of mechanical stability, is insensitive to mechanical displacement, and is particularly adapted for fabrication with superconducting materials such as niobium. 5 figs.

  14. Relativistic Shocks: Particle Acceleration and Magnetic Field Generation, and Emission

    E-Print Network [OSTI]

    Nishikawa, K I; Richardson, G; Preece, R; Sol, H; Fishman, G J

    2005-01-01

    Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g.,Buneman, Weibel and other two-stream instabilities) created in collisionless shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic jet front propagating into an ambient plasma with and without initial magnetic fields. Simulations show that the Weibel instability created in the collisionless shock front accelerates jet and ambient particles both perpendicular and parallel to the jet propagation direction. The non-linear fluctuation amplitudes of densities, currents, electric, and magnetic fields in the electron-positron shock are larger than those found in the electron-ion shock at the same simulation time. This comes from the fact that both electrons and positrons contribute to generation of the Weibel instability. The simul...

  15. Particle Acceleration, Magnetic Field Generation, and Emission in Relativistic Shocks

    E-Print Network [OSTI]

    Nishikawa, K I; Hededal, C B; Richardson, G; Preece, R; Sol, H; Fishman, G J

    2004-01-01

    Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., Buneman, Weibel and other two-stream instabilities) created in collisionless shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic jet front propagating into an ambient plasma with and without initial magnetic fields. Simulations show that the Weibel instability created in the collisionless shock front accelerates jet and ambient particles both perpendicular and parallel to the jet propagation direction. The non-linear fluctuation amplitudes of densities, currents, electric, and magnetic fields in the electron-positron shock are larger than those found in the electron-ion shock at the same simulation time. This comes from the fact that both electrons and positrons contribute to generation of the Weibel instability. While so...

  16. Enhanced dielectric-wall linear accelerator

    DOE Patents [OSTI]

    Sampayan, S.E.; Caporaso, G.J.; Kirbie, H.C.

    1998-09-22

    A dielectric-wall linear accelerator is enhanced by a high-voltage, fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 6 figs.

  17. Enhanced dielectric-wall linear accelerator

    DOE Patents [OSTI]

    Sampayan, Stephen E. (Manteca, CA); Caporaso, George J. (Livermore, CA); Kirbie, Hugh C. (Dublin, CA)

    1998-01-01

    A dielectric-wall linear accelerator is enhanced by a high-voltage, fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.

  18. High gradient accelerators for linear light sources

    SciTech Connect (OSTI)

    Barletta, W.A.

    1988-09-26

    Ultra-high gradient radio frequency linacs powered by relativistic klystrons appear to be able to provide compact sources of radiation at XUV and soft x-ray wavelengths with a duration of 1 picosecond or less. This paper provides a tutorial review of the physics applicable to scaling the present experience of the accelerator community to the regime applicable to compact linear light sources. 22 refs., 11 figs., 21 tabs.

  19. Model-independent particle accelerator tuning

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

    Scheinker, Alexander; Pang, Xiaoying; Rybarcyk, Larry

    2013-10-21

    We present a new model-independent dynamic feedback technique, rotation rate tuning, for automatically and simultaneously tuning coupled components of uncertain, complex systems. The main advantages of the method are: 1) It has the ability to handle unknown, time-varying systems, 2) It gives known bounds on parameter update rates, 3) We give an analytic proof of its convergence and its stability, and 4) It has a simple digital implementation through a control system such as the Experimental Physics and Industrial Control System (EPICS). Because this technique is model independent it may be useful as a real-time, in-hardware, feedback-based optimization scheme formore »uncertain and time-varying systems. In particular, it is robust enough to handle uncertainty due to coupling, thermal cycling, misalignments, and manufacturing imperfections. As a result, it may be used as a fine-tuning supplement for existing accelerator tuning/control schemes. We present multi-particle simulation results demonstrating the scheme’s ability to simultaneously adaptively adjust the set points of twenty two quadrupole magnets and two RF buncher cavities in the Los Alamos Neutron Science Center Linear Accelerator’s transport region, while the beam properties and RF phase shift are continuously varying. The tuning is based only on beam current readings, without knowledge of particle dynamics. We also present an outline of how to implement this general scheme in software for optimization, and in hardware for feedback-based control/tuning, for a wide range of systems.« less

  20. Symplectic Maps and Chromatic Optics in Particle Accelerators...

    Office of Scientific and Technical Information (OSTI)

    Symplectic Maps and Chromatic Optics in Particle Accelerators Citation Details In-Document Search Title: Symplectic Maps and Chromatic Optics in Particle Accelerators You are...

  1. Symplectic Maps and Chromatic Optics in Particle Accelerators...

    Office of Scientific and Technical Information (OSTI)

    Symplectic Maps and Chromatic Optics in Particle Accelerators Citation Details In-Document Search Title: Symplectic Maps and Chromatic Optics in Particle Accelerators Authors: Cai,...

  2. Development of compact linear accelerator in KBSI

    SciTech Connect (OSTI)

    Yoon, Jang-Hee; Lee, Byoung-Seob; Choi, Seyong; Park, Jin Yong; Ok, Jung-Woo; Won, Mi-Sook [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of)

    2012-02-15

    The compact linear accelerator using a 28 GHz ECRIS is under construction in KBSI, South Korea. The main capability of this facility is the production of fast neurons for the neutron radiography. The designing of a superconducting magnet, microwave transmission system, beam extraction, and plasma chamber of ECRIS were finished. The nominal axial design fields of the magnets are 3.6 T at injection and 2.2 T at extraction; the nominal radial design field strength at the plasma chamber wall is 2.1 T. We already installed 10 kW, 28 GHz gyrotron, and tested a microwave power from gyrotron using a dummy load. The current status will be discussed in this paper.

  3. The Klynac: An Integrated Klystron and Linear Accelerator

    SciTech Connect (OSTI)

    Potter, J. M., Schwellenbach, D., Meidinger, A.

    2012-08-07

    The Klynac concept integrates an electron gun, a radio frequency (RF) power source, and a coupled-cavity linear accelerator into a single resonant system

  4. The design and performance of Static Var Compensators for particle accelerators

    E-Print Network [OSTI]

    Kahle, Karsten; Genton, Charles-Mathieu

    2015-01-01

    Particle accelerators, and in particular synchrotrons, represent large cycling non-linear loads connected to the electrical distribution network. This paper discusses the typical design and performance of Static Var Compensators (SVCs) to obtain the excellent power quality levels required for particle accelerator operation.

  5. Stochastic Particle Acceleration in Parallel Relativistic Shocks

    E-Print Network [OSTI]

    Joni J. P. Virtanen; Rami Vainio

    2005-03-03

    We present results of test-particle simulations on both the first- and the second-order Fermi acceleration for relativistic parallel shock waves. Our studies suggest that the role of the second-order mechanism in the turbulent downstream of a relativistic shock may have been underestimated in the past, and that the stochastic mechanism may have significant effects on the form of the particle spectra and its time evolution.

  6. Non-accelerator particle physics

    SciTech Connect (OSTI)

    Steinberg, R.I.; Lane, C.E.

    1991-09-01

    The goals of this research are the experimental testing of fundamental theories of physics such as grand unification and the exploration of cosmic phenomena through the techniques of particle physics. We are working on the MACRO experiment, which employs a large area underground detector to search for grand unification magnetic monopoles and dark matter candidates and to study cosmic ray muons as well as low and high energy neutrinos: the {nu}IMB project, which seeks to refurbish and upgrade the IMB water Cerenkov detector to perform an improved proton decay search together with a long baseline reactor neutrino oscillation experiment using a kiloton liquid scintillator (the Perry experiment); and development of technology for improved liquid scintillators and for very low background materials in support of the MACRO and Perry experiments and for new solar neutrino experiments. 21 refs., 19 figs., 6 tabs.

  7. Automation of particle accelerator control

    SciTech Connect (OSTI)

    Silbar, R.R.; Schultz, D.E.

    1988-01-01

    We have begun a program aiming toward automatic control of charged-particle beam optics using artificial intelligence programming techniques. In developing our prototype, we are working with LISP machines and the KEE expert system shell. Our first goal was to develop a 'mouseable' representation of a typical beamline. This responds actively to changes input from the mouse or keyboard, giving an updated display of the beamline itself, its optical properties, and the instrumentation and control devices as seen by the operator. We have incorporated the Fortran beam optics code TRANSPORT for simulation of the beam. The paper describes the experience gained in this process and discusses plans to extend the work so that it is usable, in real-time, on an operating beamline. 11 refs., 2 figs.

  8. Drift tube suspension for high intensity linear accelerators

    DOE Patents [OSTI]

    Liska, D.J.; Schamaun, R.G.; Clark, D.C.; Potter, R.C.; Frank, J.A.

    1980-03-11

    The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

  9. Test particle acceleration by rotating jet magnetospheres

    E-Print Network [OSTI]

    F. M. Rieger; K. Mannheim

    2000-11-01

    Centrifugal acceleration of charged test particles at the base of a rotating jet magnetosphere is considered. Based on an analysis of forces we derive the equation for the radial accelerated motion and present an analytical solution. It is shown that for particles moving outwards along rotating magnetic field lines, the energy gain is in particular limited by the breakdown of the bead-on-the-wire approximation which occurs in the vicinity of the light cylinder $r_{L}$. The corresponding upper limit for the maximum Lorentz factor $\\gamma_{max}$ for electrons scales $\\propto B^{2/3} r_{L}^{2/3}$, with $B$ the magnetic field strength at $r_{L}$, and is at most of the order of a $10^2-10^3$ for the conditions regarded to be typical for BL Lac objects. Such values suggest that this mechanism may provide pre-accelerated seed particles which are required for efficient Fermi-type particle acceleration at larger scales in radio jets.

  10. Seventy Five Years of Particle Accelerators

    ScienceCinema (OSTI)

    Andy Sessler

    2013-06-11

    Andy Sessler, Berkeley Lab director from 1973 to 1980, sheds light on the Lab's nearly eight-decade history of inventing and refining particle accelerators, which continue to illuminate the nature of the universe. His talk was presented July 26, 2006.

  11. Laser Plasma Particle Accelerators: Large Fields for Smaller Facility Sources

    E-Print Network [OSTI]

    Geddes, Cameron G.R.

    2010-01-01

    of high- gradient, laser plasma particle accelerators.accelerators that use laser-driven plasma waves. Theseleft) showing the laser (red), plasma wake density (purple-

  12. Relativistic Shocks: Particle Acceleration and Magnetic Field Generation, and Emission

    E-Print Network [OSTI]

    K. -I. Nishikawa; P. Hardee; G. Richardson; R. Preece; H. Sol; G. J. Fishman

    2004-10-07

    Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g.,Buneman, Weibel and other two-stream instabilities) created in collisionless shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic jet front propagating into an ambient plasma with and without initial magnetic fields. Simulations show that the Weibel instability created in the collisionless shock front accelerates jet and ambient particles both perpendicular and parallel to the jet propagation direction. The non-linear fluctuation amplitudes of densities, currents, electric, and magnetic fields in the electron-positron shock are larger than those found in the electron-ion shock at the same simulation time. This comes from the fact that both electrons and positrons contribute to generation of the Weibel instability. The simulation results show that the Weibel instability is responsible for generating and amplifying nonuniform, small-scale (mainly transverse) magnetic fields which contribute to the electron's (positron's) transverse deflection behind the jet head. This small scale magnetic field structure is appropriate to the generation of ``jitter'' radiation from deflected electrons (positrons) as opposed to synchrotron radiation.

  13. Kerr Naked Singularities as Particle Accelerators

    E-Print Network [OSTI]

    Mandar Patil; Pankaj S. Joshi

    2011-11-16

    We investigate here the particle acceleration by Kerr naked singularities. We consider a collision between particles dropped in from infinity at rest, which follow geodesic motion in the equatorial plane, with their angular momenta in an appropriate finite range of values. When an event horizon is absent, an initially infalling particle turns back as an outgoing particle, when it has the angular momentum in an appropriate range of values, which then collides with infalling particles. When the collision takes place close to what would have been the event horizon in the extremal case, the center of mass energy of collision is arbitrarily large, depending on how close is the overspinning Kerr geometry to the extremal case. Thus the fast rotating Kerr configurations if they exist in nature could provide an excellent cosmic laboratory to probe ultra-high-energy physics.

  14. On particle acceleration around shocks. I

    E-Print Network [OSTI]

    Mario Vietri

    2003-03-28

    We derive a relativistically covariant (although not manifestly so) equation for the distribution function of particles accelerated at shocks, which applies also to extremely relativistic shocks, and arbitrarily anisotropic particle distributions. The theory is formulated for arbitrary pitch angle scattering, and reduces to the well--known case for small angle scatterings via a Fokker--Planck approximation. The boundary conditions for the problem are completely reformulated introducing a physically motivated Green's function; the new formulation allows derivation of the particle spectrum both close and far away from the injection energy in an exact way, while it can be shown to reduce to a power--law at large particle energies. The particle spectral index is also recovered in a novel way. Contact is made with the Newtonian treatment.

  15. Longitudinal jitter analysis of linear accelerator electron gun

    E-Print Network [OSTI]

    Mingshan, Liu; Iqbal, Munawar

    2015-01-01

    We present measurement and analyses of longitudinal timing jitter of Beijing Electron Positron Collider (BEPCII) linear accelerator electron gun. We simulated longitudinal jitter effect of the gun using PARMELA about beam performance including beam profile, average energy, energy spread, longitudinal phase of reference particle and XY emittance. The maximum percentage difference of the beam parameters are calculated to be; 100%, 13.27%, 42.24%, 7.79% and 65.01%, 86.81%, respectively due to which the bunching efficiency is reduced to 54%. The simulation results are in agreement with test and are helpful to optimize the beam parameters by tuning the trigger timing of the gun during the bunching process.

  16. Naked singularities as particle accelerators. II

    SciTech Connect (OSTI)

    Patil, Mandar; Joshi, Pankaj S.; Malafarina, Daniele

    2011-03-15

    We generalize here our earlier results on particle acceleration by naked singularities. We showed recently [M. Patil and P. S. Joshi, Phys. Rev. D 82, 104049 (2010).] that the naked singularities that form due to the gravitational collapse of massive stars provide a suitable environment where particles could get accelerated and collide at arbitrarily high center-of-mass energies. However, we focused there only on the spherically symmetric gravitational collapse models, which were also assumed to be self-similar. In this paper, we broaden and generalize the result to all gravitational collapse models leading to the formation of a naked singularity as the final state of collapse, evolving from a regular initial data, without making any prior restrictive assumptions about the spacetime symmetries such as above. We show that, when the particles interact and collide near the Cauchy horizon, the energy of collision in the center-of-mass frame will be arbitrarily high, thus offering a window to the Planck scale physics. We also consider the issue of various possible physical mechanisms of generation of such very high-energy particles from the vicinity of naked singularity. We then construct a model of gravitational collapse to a timelike naked singularity to demonstrate the working of these ideas, where the pressure is allowed to be negative, but the energy conditions are respected. We show that a finite amount of mass-energy density has to be necessarily radiated away from the vicinity of the naked singularity as the collapse evolves. Therefore, the nature of naked singularities, both at the classical and quantum level, could play an important role in the process of particle acceleration, explaining the occurrence of highly energetic outgoing particles in the vicinity of the Cauchy horizon that participate in extreme high-energy collisions.

  17. Automatic beam path analysis of laser wakefield particle acceleration data

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    Automatic beam path analysis of laser wakefield particle acceleration data Oliver Rübel1 in a pipeline fashion to automatically locate and analyze high-energy particle bunches undergoing acceleration

  18. Neutron Sciences Staff Give Back, Teach US Particle Accelerator...

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

    Neutron Sciences Staff Give Back, Teach US Particle Accelerator School Courses Katie Bethea - March 13, 2014 Neutron Science Directorate staff hosted students from the US Particle...

  19. Linear Fixed-Field Multi-Pass Arcs for Recirculating Linear Accelerators

    SciTech Connect (OSTI)

    V.S. Morozov, S.A. Bogacz, Y.R. Roblin, K.B. Beard

    2012-06-01

    Recirculating Linear Accelerators (RLA's) provide a compact and efficient way of accelerating particle beams to medium and high energies by reusing the same linac for multiple passes. In the conventional scheme, after each pass, the different energy beams coming out of the linac are separated and directed into appropriate arcs for recirculation, with each pass requiring a separate fixed-energy arc. In this paper we present a concept of an RLA return arc based on linear combined-function magnets, in which two and potentially more consecutive passes with very different energies are transported through the same string of magnets. By adjusting the dipole and quadrupole components of the constituting linear combined-function magnets, the arc is designed to be achromatic and to have zero initial and final reference orbit offsets for all transported beam energies. We demonstrate the concept by developing a design for a droplet-shaped return arc for a dog-bone RLA capable of transporting two beam passes with momenta different by a factor of two. We present the results of tracking simulations of the two passes and lay out the path to end-to-end design and simulation of a complete dog-bone RLA.

  20. Canonical Particle Acceleration in FRI Radio Galaxies

    E-Print Network [OSTI]

    Andrew Young; Lawrence Rudnick; Debora Katz; Tracey DeLaney; Namir E. Kassim; Kazuo Makishima

    2005-02-26

    Matched resolution multi-frequency VLA observations of four radio galaxies are used to derive the asymptotic low energy slope of the relativistic electron distribution. Where available, low energy slopes are also determined for other sources in the literature. They provide information on the acceleration physics independent of radiative and other losses, which confuse measurements of the synchrotron spectra in most radio, optical and X-ray studies. We find a narrow range of inferred low energy electron energy slopes, n(E)=const*E^-2.1 for the currently small sample of lower luminosity sources classified as FRI (not classical doubles). This distribution is close to, but apparently inconsistent with, the test particle limit of n(E)=const*E^-2.0 expected from strong diffusive shock acceleration in the non-relativistic limit. Relativistic shocks or those modified by the back-pressure of efficiently accelerated cosmic rays are two alternatives to produce somewhat steeper spectra. We note for further study the possiblity of acceleration through shocks, turbulence or shear in the flaring/brightening regions in FRI jets as they move away from the nucleus. Jets on pc scales and the collimated jets and hot spots of FRII (classical double) sources would be governed by different acceleration sites and mechanisms; they appear to show a much wider range of spectra than for FRI sources.

  1. PRODUCTION AND APPLICATIONS OF NEUTRONS USING PARTICLE ACCELERATORS

    SciTech Connect (OSTI)

    David L. Chichester

    2009-11-01

    Advances in neutron science have gone hand in hand with the development and of particle accelerators from the beginning of both fields of study. Early accelerator systems were developed simply to produce neutrons, allowing scientists to study their properties and how neutrons interact in matter, but people quickly realized that more tangible uses existed too. Today the diversity of applications for industrial accelerator-based neutron sources is high and so to is the actual number of instruments in daily use is high, and they serve important roles in the fields where they're used. This chapter presents a technical introduction to the different ways particle accelerators are used to produce neutrons, an historical overview of the early development of neutron-producing particle accelerators, a description of some current industrial accelerator systems, narratives of the fields where neutron-producing particle accelerators are used today, and comments on future trends in the industrial uses of neutron producing particle accelerators.

  2. The Klynac: An integrated klystron and linear accelerator

    SciTech Connect (OSTI)

    Potter, James M. [JP Accelerator Works, Inc., 2245 47th Street, Los Alamos NM 87544 (United States); Schwellenbach, David; Meidinger, Alfred [National Security Technologies, LLC, Los Alamos Operations, P.O. Box 809, Los Alamos NM 87544 (United States)

    2013-04-19

    The Klynac concept integrates an electron gun, a radio frequency (RF) power source, and a coupled-cavity linear accelerator into a single resonant system. The klystron is essentially a conventional klystron structure with an input cavity, some number of intermediate cavities and an output cavity. The accelerator structure is, likewise, a conventional on-axis coupled structure. The uniqueness is the means of coupling the klystron output cavity to the accelerator. The coupler is a resonant coupler rather than an ordinary transmission line. The geometry of such a system need not be coaxial. However, if the klystron and accelerator are coaxial we can eliminate the need for a separate cathode for the accelerator by injecting some of the klystron beam into the accelerator. Such a device can be made cylindrical which is ideal for some applications.

  3. The Klynac: An Integrated Klystron and Linear Accelerator

    SciTech Connect (OSTI)

    Potter, J. M. [JP Accelerator Works; Schwellenbach, D. [NSTec

    2013-04-01

    The Klynac concept integrates an electron gun, a radio frequency (RF) power source, and a coupled-cavity linear accelerator into a single resonant system. The klystron is essentially a conventional klystron structure with an input cavity, some number of intermediate cavities and an output cavity. The accelerator structure is, likewise, a conventional on-axis coupled structure. The uniqueness is the means of coupling the klystron output cavity to the accelerator. The coupler is a resonant coupler rather than an ordinary transmission line. The geometry of such a system need not be coaxial. However, if the klystron and accelerator are coaxial we can eliminate the need for a separate cathode for the accelerator by injecting some of the klystron beam into the accelerator. Such a device can be made cylindrical which is ideal for some applications.

  4. 43 PARTICLE ACCELERATORS; ELECTRON GUNS; BEAM EMITTANCE; CHARGE

    Office of Scientific and Technical Information (OSTI)

    SPACE 430200* -- Particle Accelerators-- Beam Dynamics, Field Calculations, & Ion Optics The evolution of the electron-beam phase space distribution in laser-driven rf guns is...

  5. Mechanical features of the ATS RFQ linear accelerator

    SciTech Connect (OSTI)

    Wilson, N.G.; Hayward, T.D.; Lind, G.W.

    1983-01-01

    A radio-frequency quadrupole (RFQ) linear accelerator has been constructed and placed in operation on the Los Alamos National Laboratory accelerator test stand (ATS). This accelerator uses an evacuated rf manifold to distribute rf excitation from the 425-MHz rf power supply to the slot-coupled, RFQ vane-cavity, resonator assembly. The RFQ vanes are supported on commercially available copper-plated, linear, resilient C-seals to provide a high-conductivity rf contact that permits aligning and positioning the vanes during tuning, and demounting the vanes for evaluation and modification as necessary. All rf structures are fabricated from stress-relieved, bright-acid copper-plated carbon steel. Measurements made on the accelerator as assembled have demonstrated >8000 vane-cavity Q at the quadrupole's approx. 423.400-MHz accelerating-mode frequency. Operating manifold vacuum of 3 to 6 x 10/sup -8/ torr has been observed after rf conditioning; conditioning required 150 h for stable high-power rf operation. Experience to date has indicated the desirability of modifying the vane rf-contact seat configuration to improve assembly and alignment procedures, improving vane-machining processes to increase vane straightness, installing periodic vane-shorting rings to minimize the effect of dipole modes in the quadrupole accelerating structure,and modifying the waveguide-coupling slot in the manifold to improve forward rf power flow.

  6. Separated-orbit bisected energy-recovered linear accelerator

    DOE Patents [OSTI]

    Douglas, David R.

    2015-09-01

    A separated-orbit bisected energy-recovered linear accelerator apparatus and method. The accelerator includes a first linac, a second linac, and a plurality of arcs of differing path lengths, including a plurality of up arcs, a plurality of downgoing arcs, and a full energy arc providing a path independent of the up arcs and downgoing arcs. The up arcs have a path length that is substantially a multiple of the RF wavelength and the full energy arc includes a path length that is substantially an odd half-integer multiple of the RF wavelength. Operation of the accelerator includes accelerating the beam utilizing the linacs and up arcs until the beam is at full energy, at full energy executing a full recirculation to the second linac using a path length that is substantially an odd half-integer of the RF wavelength, and then decelerating the beam using the linacs and downgoing arcs.

  7. Particle Acceleration and Magnetic Field Generation in Electron-Positron Relativistic Shocks

    E-Print Network [OSTI]

    Nishikawa, K I; Richardson, G; Preece, R; Sol, H; Fishman, G J

    2004-01-01

    Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., Buneman, Weibel and other two-stream instabilities) created in collisionless shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic electron-positron jet front propagating into an ambient electron-positron plasma with and without initial magnetic fields. Simulations show that the Weibel instability created in the collisionless shock front accelerates jet and ambient particles both perpendicular and parallel to the jet propagation direction. The non-linear fluctuation amplitudes of densities, currents, electric, and magnetic fields in the electron-positron shock are larger than those found in the electron-ion shock studied in a previous paper at the comparable simulation time. This comes from the fact that both electrons and ...

  8. Acceleration of low energy charged particles by gravitational waves

    E-Print Network [OSTI]

    G. Voyatzis; L. Vlahos; S. Ichtiaroglou; D. Papadopoulos

    2005-12-07

    The acceleration of charged particles in the presence of a magnetic field and gravitational waves is under consideration. It is shown that the weak gravitational waves can cause the acceleration of low energy particles under appropriate conditions. Such conditions may be satisfied close to the source of the gravitational waves if the magnetized plasma is in a turbulent state.

  9. Means and method for the focusing and acceleration of parallel beams of charged particles

    DOE Patents [OSTI]

    Maschke, Alfred W. (East Moriches, NY)

    1983-07-05

    A novel apparatus and method for focussing beams of charged particles comprising planar arrays of electrostatic quadrupoles. The quadrupole arrays may comprise electrodes which are shared by two or more quadrupoles. Such quadrupole arrays are particularly adapted to providing strong focussing forces for high current, high brightness, beams of charged particles, said beams further comprising a plurality of parallel beams, or beamlets, each such beamlet being focussed by one quadrupole of the array. Such arrays may be incorporated in various devices wherein beams of charged particles are accelerated or transported, such as linear accelerators, klystron tubes, beam transport lines, etc.

  10. A particle accelerator employing transient space charge potentials

    DOE Patents [OSTI]

    Post, R.F.

    1988-02-25

    The invention provides an accelerator for ions and charged particles. The plasma is generated and confined in a magnetic mirror field. The electrons of the plasma are heated to high temperatures. A series of local coils are placed along the axis of the magnetic mirror field. As an ion or particle beam is directed along the axis in sequence the coils are rapidly pulsed creating a space charge to accelerate and focus the beam of ions or charged particles. 3 figs.

  11. Finite element analyses of a linear-accelerator electron gun

    SciTech Connect (OSTI)

    Iqbal, M. E-mail: muniqbal@ihep.ac.cn; Wasy, A.; Islam, G. U.; Zhou, Z.

    2014-02-15

    Thermo-structural analyses of the Beijing Electron-Positron Collider (BEPCII) linear-accelerator, electron gun, were performed for the gun operating with the cathode at 1000?°C. The gun was modeled in computer aided three-dimensional interactive application for finite element analyses through ANSYS workbench. This was followed by simulations using the SLAC electron beam trajectory program EGUN for beam optics analyses. The simulations were compared with experimental results of the assembly to verify its beam parameters under the same boundary conditions. Simulation and test results were found to be in good agreement and hence confirmed the design parameters under the defined operating temperature. The gun is operating continuously since commissioning without any thermal induced failures for the BEPCII linear accelerator.

  12. Beam dynamics in a long-pulse linear induction accelerator

    SciTech Connect (OSTI)

    Ekdahl, Carl; Abeyta, Epifanio O; Aragon, Paul; Archuleta, Rita; Cook, Gerald; Dalmas, Dale; Esquibel, Kevin; Gallegos, Robert A; Garnett, Robert; Harrison, James F; Johnson, Jeffrey B; Jacquez, Edward B; Mc Cuistian, Brian T; Montoya, Nicholas A; Nath, Subrato; Nielsen, Kurt; Oro, David; Prichard, Benjamin; Rose, Chris R; Sanchez, Manolito; Schauer, Martin M; Seitz, Gerald; Schulze, Martin; Bender, Howard A; Broste, William B; Carlson, Carl A; Frayer, Daniel K; Johnson, Douglas E; Tom, C Y; Trainham, C; Williams, John; Scarpetti, Raymond; Genoni, Thomas; Hughes, Thomas; Toma, Carsten

    2010-01-01

    The second axis of the Dual Axis Radiography of Hydrodynamic Testing (DARHT) facility produces up to four radiographs within an interval of 1.6 microseconds. It accomplishes this by slicing four micro-pulses out of a long 1.8-kA, 16.5-MeV electron beam pulse and focusing them onto a bremsstrahlung converter target. The long beam pulse is created by a dispenser cathode diode and accelerated by the unique DARHT Axis-II linear induction accelerator (LIA). Beam motion in the accelerator would be a problem for radiography. High frequency motion, such as from beam breakup instability, would blur the individual spots. Low frequency motion, such as produced by pulsed power variation, would produce spot to spot differences. In this article, we describe these sources of beam motion, and the measures we have taken to minimize it.

  13. Linear induction accelerator and pulse forming networks therefor

    DOE Patents [OSTI]

    Buttram, Malcolm T. (Sandia Park, NM); Ginn, Jerry W. (Albuquerque, NM)

    1989-01-01

    A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities.

  14. Superstructure for high current applications in superconducting linear accelerators

    DOE Patents [OSTI]

    Sekutowicz, Jacek (Elbchaussee, DE); Kneisel, Peter (Williamsburg, VA)

    2008-03-18

    A superstructure for accelerating charged particles at relativistic speeds. The superstructure consists of two weakly coupled multi-cell subunits equipped with HOM couplers. A beam pipe connects the subunits and an HOM damper is included at the entrance and the exit of each of the subunits. A coupling device feeds rf power into the subunits. The subunits are constructed of niobium and maintained at cryogenic temperatures. The length of the beam pipe between the subunits is selected to provide synchronism between particles and rf fields in both subunits.

  15. Accelerated Iterative Method for Solving Steady Solutions of Linearized Atmospheric Models

    E-Print Network [OSTI]

    Watanabe, Masahiro

    Accelerated Iterative Method for Solving Steady Solutions of Linearized Atmospheric Models Masahiro approach, referred to as the accelerated iterative method (AIM), is developed for solving steady state, respectively. For ensuring the accelerated asymptotic convergence of iterative procedure

  16. Exploring Particle Acceleration in Gamma-Ray Binaries

    E-Print Network [OSTI]

    Bosch-Ramon, V

    2011-01-01

    Binary systems can be powerful sources of non-thermal emission from radio to gamma rays. When the latter are detected, then these objects are known as gamma-ray binaries. In this work, we explore, in the context of gamma-ray binaries, different acceleration processes to estimate their efficiency: Fermi I, Fermi II, shear acceleration, the converter mechanism, and magnetic reconnection. We find that Fermi I acceleration in a mildly relativistic shock can provide, although marginally, the multi-10 TeV particles required to explain observations. Shear acceleration may be a complementary mechanism, giving particles the final boost to reach such a high energies. Fermi II acceleration may be too slow to account for the observed very high energy photons, but may be suitable to explain extended low-energy emission. The converter mechanism seems to require rather high Lorentz factors but cannot be discarded a priori. Standard relativistic shock acceleration requires a highly turbulent, weakly magnetized downstream med...

  17. Seventy Five Years of Particle Accelerators (LBNL Summer Lecture Series)

    ScienceCinema (OSTI)

    Sessler, Andy

    2011-04-28

    Summer Lecture Series 2006: Andy Sessler, Berkeley Lab director from 1973 to 1980, sheds light on the Lab's nearly eight-decade history of inventing and refining particle accelerators, which continue to illuminate the nature of the universe.

  18. A GPU Accelerated Smoothed Particle Hydrodynamics Capability For Houdini 

    E-Print Network [OSTI]

    Sanford, Mathew

    2012-10-19

    on the desired result. One common fluid simulation technique is the Smoothed Particle Hydrodynamics (SPH) method. This method is highly parellelizable. I have implemented a method to integrate a Graphics Processor Unit (GPU) accelerated SPH capability into the 3D...

  19. Towards radiation pressure acceleration of protons using linearly polarized ultrashort petawatt laser pulses

    E-Print Network [OSTI]

    Kim, I Jong; Kim, Chul Min; Kim, Hyung Taek; Sung, Jae Hee; Lee, Seong Ku; Yu, Tae Jun; Choi, Il Woo; Lee, Chang-Lyoul; Nam, Kee Hwan; Nickles, Peter V; Jeong, Tae Moon; Lee, Jongmin

    2013-01-01

    Particle acceleration using ultraintense, ultrashort laser pulses is one of the most attractive topics in relativistic laser-plasma research. We report proton/ion acceleration in the intensity range of 5x1019 W/cm2 to 3.3x1020 W/cm2 by irradiating linearly polarized, 30-fs, 1-PW laser pulses on 10- to 100-nm-thick polymer targets. The proton energy scaling with respect to the intensity and target thickness was examined. The experiments demonstrated, for the first time with linearly polarized light, a transition from the target normal sheath acceleration to radiation pressure acceleration and showed a maximum proton energy of 45 MeV when a 10-nm-thick target was irradiated by a laser intensity of 3.3x1020 W/cm2. The experimental results were further supported by two- and three-dimensional particle-in-cell simulations. Based on the deduced proton energy scaling, proton beams having an energy of ~ 200 MeV should be feasible at a laser intensity of 1.5x1021 W/cm2.

  20. Particle Acceleration in three dimensional Reconnection Regions: A New Test Particle Approach

    E-Print Network [OSTI]

    Rudiger Schopper; Guido T. Birk; Harald Lesch

    2001-06-29

    Magnetic Reconnection is an efficient and fast acceleration mechanism by means of direct electric field acceleration parallel to the magnetic field. Thus, acceleration of particles in reconnection regions is a very important topic in plasma astrophysics. This paper shows that the conventional analytical models and numerical test particle investigations can be misleading concerning the energy distribution of the accelerated particles, since they oversimplify the electric field structure by the assumption that the field is homogeneous. These investigations of the acceleration of charged test particles are extended by considering three-dimensional field configurations characterized by localized field-aligned electric fields. Moreover, effects of radiative losses are discussed. The comparison between homogeneous and inhomogeneous electric field acceleration in reconnection regions shows dramatic differences concerning both, the maximum particle energy and the form of the energy distribution.

  1. RECENT PROGRESS TOWARD A MUON RECIRCULATING LINEAR ACCELERATOR

    SciTech Connect (OSTI)

    Slawomir Bogacz, Vasiliy Morozov, Yves Roblin, Kevin Beard

    2012-07-01

    Both Neutrino Factories (NF) and Muon Colliders (MC) require very rapid acceleration due to the short lifetime of muons. After a capture and bunching section, a linac raises the energy to about 900 MeV, and is followed by one or more Recirculating Linear Accelerators (RLA), possibly followed by a Rapid Cycling Synchnotron (RCS) or Fixed-Field Alternating Gradient (FFAG) ring. A RLA reuses the expensive RF linac section for a number of passes at the price of having to deal with different energies within the same linac. Various techniques including pulsed focusing quadruopoles, beta frequency beating, and multipass arcs have been investigated via simulations to improve the performance and reduce the cost of such RLAs.

  2. A Novel Linear Accelerator For Image Guided Radiation Therapy

    SciTech Connect (OSTI)

    Ding Xiaodong; Boucher, Salime [RadiaBeam Technologies, 1717 Stewart St., Santa Monica, CA 90404 (United States)

    2011-06-01

    RadiaBeam is developing a novel linear accelerator which produces both kilovoltage ({approx}100 keV) X-rays for imaging, and megavoltage (6 to 20 MeV) X-rays for therapy. We call this system the DEXITron: Dual Energy X-ray source for Imaging and Therapy. The Dexitron is enabled by an innovation in the electromagnetic design of the linac, which allows the output energy to be rapidly switched from high energy to low energy. In brief, the method involves switching the phase of the radiofrequency (RF) power by 180 degrees at some point in the linac such that, after that point, the linac decelerates the beam, rather than accelerating it. The Dexitron will have comparable cost to other linacs, and avoids the problems associated with current IGRT equipment.

  3. Particle acceleration by fluctuating electric fields at a magnetic field null point

    E-Print Network [OSTI]

    P. Petkaki; A. L. MacKinnon

    2007-07-09

    Particle acceleration consequences from fluctuating electric fields superposed on an X-type magnetic field in collisionless solar plasma are studied. Such a system is chosen to mimic generic features of dynamic reconnection, or the reconnective dissipation of a linear disturbance. We explore numerically the consequences for charged particle distributions of fluctuating electric fields superposed on an X-type magnetic field. Particle distributions are obtained by numerically integrating individual charged particle orbits when a time varying electric field is superimposed on a static X-type neutral point. This configuration represents the effects of the passage of a generic MHD disturbance through such a system. Different frequencies of the electric field are used, representing different possible types of wave. The electric field reduces with increasing distance from the X-type neutral point as in linear dynamic magnetic reconnection. The resulting particle distributions have properties that depend on the amplitude and frequency of the electric field. In many cases a bimodal form is found. Depending on the timescale for variation of the electric field, electrons and ions may be accelerated to different degrees and often have energy distributions of different forms. Protons are accelerated to $\\gamma$-ray producing energies and electrons to and above hard X-ray producing energies in timescales of 1 second. The acceleration mechanism is possibly important for solar flares and solar noise storms but is also applicable to all collisionless plasmas.

  4. Accelerated lifetime testing of energy storage capacitors used in particle accelerators power converters

    E-Print Network [OSTI]

    Boattini, Fulvio

    2015-01-01

    Energy storage capacitors are used in large quantities in high power converters for particle accelerators. In this application capacitors see neither a DC nor an AC voltage but a combination of the two. The paper presents a new power converter explicitly designed to perform accelerated testing on these capacitors and the results of the tests.

  5. Magnetic reconnection configurations and particle acceleration in solar flares

    E-Print Network [OSTI]

    Chen, P. F.

    types of solar flares. Upper panel: two-ribbon flares; Lower panel: compact flares. The color showsMagnetic reconnection configurations and particle acceleration in solar flares P. F. Chen, W. J space under different magnetic configurations. Key words: solar flares, magnetic reconnection, particle

  6. End-to-end absolute energy calibration of atmospheric fluorescence telescopes by an electron linear accelerator

    E-Print Network [OSTI]

    End-to-end absolute energy calibration of atmospheric fluorescence telescopes by an electron linear of fluorescence telescopes by using air showers induced by electron beams from a linear accelerator, which and constructing a compact linear accelerator with a maximum electron energy of 40 MeV and an intensity of 6.4 m

  7. Berkeley Lab Particle Accelerator Sets World Record

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAudits & Inspections AuditsBarbara2.0.1BenBerkeley Lab Particle

  8. Particle acceleration via reconnection processes in the supersonic solar wind

    SciTech Connect (OSTI)

    Zank, G. P.; Le Roux, J. A.; Webb, G. M.; Dosch, A.; Khabarova, O.

    2014-12-10

    An emerging paradigm for the dissipation of magnetic turbulence in the supersonic solar wind is via localized small-scale reconnection processes, essentially between quasi-2D interacting magnetic islands. Charged particles trapped in merging magnetic islands can be accelerated by the electric field generated by magnetic island merging and the contraction of magnetic islands. We derive a gyrophase-averaged transport equation for particles experiencing pitch-angle scattering and energization in a super-Alfvénic flowing plasma experiencing multiple small-scale reconnection events. A simpler advection-diffusion transport equation for a nearly isotropic particle distribution is derived. The dominant charged particle energization processes are (1) the electric field induced by quasi-2D magnetic island merging and (2) magnetic island contraction. The magnetic island topology ensures that charged particles are trapped in regions where they experience repeated interactions with the induced electric field or contracting magnetic islands. Steady-state solutions of the isotropic transport equation with only the induced electric field and a fixed source yield a power-law spectrum for the accelerated particles with index ? = –(3 + M{sub A} )/2, where M{sub A} is the Alfvén Mach number. Considering only magnetic island contraction yields power-law-like solutions with index –3(1 + ? {sub c}/(8?{sub diff})), where ? {sub c}/?{sub diff} is the ratio of timescales between magnetic island contraction and charged particle diffusion. The general solution is a power-law-like solution with an index that depends on the Alfvén Mach number and the timescale ratio ?{sub diff}/? {sub c}. Observed power-law distributions of energetic particles observed in the quiet supersonic solar wind at 1 AU may be a consequence of particle acceleration associated with dissipative small-scale reconnection processes in a turbulent plasma, including the widely reported c {sup –5} (c particle speed) spectra observed by Fisk and Gloeckler and Mewaldt et al.

  9. Acceleration of Energetic Particles Through Self-Generated Waves in a Decelerating Coronal Shock

    E-Print Network [OSTI]

    Sanahuja, Blai

    Acceleration of Energetic Particles Through Self-Generated Waves in a Decelerating Coronal Shock M the Alfvén waves responsible for the diffusive acceleration of particles are generated by the accelerated coupled SEP acceleration and Alfvén wave self- generation model [5], the particles are simulated

  10. 2011 Annual Planning Summary for Stanford Linear Accelerator Center Site Office (SLAC)

    Broader source: Energy.gov [DOE]

    The ongoing and projected Environmental Assessments and Environmental Impact Statements for 2011 and 2012 within the Stanford Linear Accelerator Center Site Office (SLAC SO) (See also Science).

  11. Particle acceleration at corotating interaction regions in the heliosphere

    SciTech Connect (OSTI)

    Tsubouchi, K., E-mail: kent1@mac.com [Department of Earth and Planetary Science, Tokyo Institute of Technology, Ookayama 2-21-1, Tokyo 152-8551 (Japan)

    2014-11-01

    Hybrid simulations are performed to investigate the dynamics of both solar wind protons and interplanetary pickup ions (PUIs) around the corotating interaction region (CIR). The one-dimensional system is applied in order to focus on processes in the direction of CIR propagation. The CIR is bounded by forward and reverse shocks, which are responsible for particle acceleration. The effective acceleration of solar wind protons takes place when the reverse shock (fast wind side) favors a quasi-parallel regime. The diffusive process accounts for this acceleration, and particles can gain energy in a suprathermal range (on the order of 10 keV). In contrast, the PUI acceleration around the shock differs from the conventional model in which the motional electric field along the shock surface accelerates particles. Owing to their large gyroradius, PUIs can gyrate between the upstream and downstream, several proton inertial lengths away from the shock. This 'cross-shock' gyration results in a net velocity increase in the field-aligned component, indicating that the magnetic mirror force is responsible for acceleration. The PUIs that remain in the vicinity of the shock for a long duration (tens of gyroperiods) gain much energy and are reflected back toward the upstream. These reflected energetic PUIs move back and forth along the magnetic field between a pair of CIRs that are magnetically connected. The PUIs are repeatedly accelerated in each reflection, leading to a maximum energy gain close to 100 keV. This mechanism can be evaluated in terms of 'preacceleration' for the generation of anomalous cosmic rays.

  12. Accurate and efficient spin integration for particle accelerators

    E-Print Network [OSTI]

    Abell, Dan T; Ranjbar, Vahid H; Barber, Desmond P

    2015-01-01

    Accurate spin tracking is a valuable tool for understanding spin dynamics in particle accelerators and can help improve the performance of an accelerator. In this paper, we present a detailed discussion of the integrators in the spin tracking code gpuSpinTrack. We have implemented orbital integrators based on drift-kick, bend-kick, and matrix-kick splits. On top of the orbital integrators, we have implemented various integrators for the spin motion. These integrators use quaternions and Romberg quadratures to accelerate both the computation and the convergence of spin rotations. We evaluate their performance and accuracy in quantitative detail for individual elements as well as for the entire RHIC lattice. We exploit the inherently data-parallel nature of spin tracking to accelerate our algorithms on graphics processing units.

  13. On the novel mechanism of acceleration of cosmic particles

    E-Print Network [OSTI]

    Osmanov, Z

    2015-01-01

    A novel model of particle acceleration in the rotating magnetospheres of active galactic nuclei (AGN) and pulsars is constructed. The particle energies may be boosted up to enormous energies in a several step mechanism. In the first stage, the Langmuir waves are centrifugally excited and amplified by means of a parametric process that efficiently pumps rotational energy to excite electrostatic fields. By considering the pulsars it is shown that the Langmuir waves very soon Landau damp on the relativistic electrons already present in a magnetosphere. It has been found that the process is so efficient that no energy losses might affect the mechanism of particle acceleration. Applying typical parameters for young pulsars we have shown that by means of this process the electrons might achieve energies of the order of $10^{18}$ eV. The situation in AGN magnetospheres is slightly different. In the second stage, the process of "Langmuir collapse" develops, creating appropriate conditions for transferring electric en...

  14. Environmental Survey preliminary report, Stanford Linear Accelerator Center, Stanford, California

    SciTech Connect (OSTI)

    Not Available

    1988-07-01

    This report presents the preliminary findings from the first phase of the Survey of the US Department of Energy (DOE) Stanford Linear Accelerator Center (SLAC) at Stanford, California, conducted February 29 through March 4, 1988. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are being supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with the SLAC. The Survey covers all environmental media and all areas of environmental regulation and is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations at the SLAC, and interviews with site personnel. The Survey team is developing a Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during its on-site activities. The Sampling and Analysis Plan will be executed by a DOE National Laboratory or a support contractor. When completed, the results will be incorporated into the Environmental Survey Interim Report for the SLAC facility. The Interim Report will reflect the final determinations of the SLAC Survey. 95 refs., 25 figs., 25 tabs.

  15. Estimation of Radiation Protection Shielding for a EURISOL Linear Proton Accelerator

    E-Print Network [OSTI]

    Thomas Otto, CERN

    A linear accelerator for protons, based on superconducting radiofrequency technology, is envisaged as a driver accelerator for the isotope production targets in a future EURISOL facility. This note reports basic estimates of the required radiation protection shielding of such an accelerator.

  16. Single particles accelerate final stages of capillary break up

    E-Print Network [OSTI]

    Lindner, Anke; Wagner, Christian

    2015-01-01

    Droplet formation of suspensions is present in many industrial and technological processes such as coating and food engineering. Whilst the finite time singularity of the minimum neck diameter in capillary break-up of simple liquids can be described by well known self-similarity solutions, the pinching of non-Brownian suspension depends in a complex way on the particle dynamics in the thinning thread. Here we focus on the very dilute regime where the filament contains only isolated beads to identify the physical mechanisms leading to the pronounced acceleration of the filament thinning observed. This accelerated regime is characterized by an asymmetric shape of the filament with an enhanced curvature that depends on the size and the spatial distribution of the particles within the capillary thread.

  17. Single particles accelerate final stages of capillary break up

    E-Print Network [OSTI]

    Anke Lindner; Jorge Eduardo Fiscina; Christian Wagner

    2015-06-12

    Droplet formation of suspensions is present in many industrial and technological processes such as coating and food engineering. Whilst the finite time singularity of the minimum neck diameter in capillary break-up of simple liquids can be described by well known self-similarity solutions, the pinching of non-Brownian suspension depends in a complex way on the particle dynamics in the thinning thread. Here we focus on the very dilute regime where the filament contains only isolated beads to identify the physical mechanisms leading to the pronounced acceleration of the filament thinning observed. This accelerated regime is characterized by an asymmetric shape of the filament with an enhanced curvature that depends on the size and the spatial distribution of the particles within the capillary thread.

  18. Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications

    SciTech Connect (OSTI)

    Brown, Michael R.

    2006-11-16

    Project Title: Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications PI: Michael R. Brown, Swarthmore College The purpose of the project was to provide theoretical and modeling support to the Swarthmore Spheromak Experiment (SSX). Accordingly, the theoretical effort was tightly integrated into the SSX experimental effort. During the grant period, Michael Brown and his experimental collaborators at Swarthmore, with assistance from W. Matthaeus as appropriate, made substantial progress in understanding the physics SSX plasmas.

  19. Charlton, L.A.; Difilippo, F.C. 43 PARTICLE ACCELERATORS; 99...

    Office of Scientific and Technical Information (OSTI)

    43 PARTICLE ACCELERATORS; 99 MATHEMATICS, COMPUTERS, INFORMATION SCIENCE, MANAGEMENT, LAW, MISCELLANEOUS; Spallation; Spallation; Neutron Sources; Neutron Sources; Target...

  20. Tuning the DARHT Axis-II linear induction accelerator focusing

    SciTech Connect (OSTI)

    Ekdahl, Carl A. [Los Alamos National Laboratory

    2012-04-24

    Flash radiography of large hydrodynamic experiments driven by high explosives is a well-known diagnostic technique in use at many laboratories, and the Dual-Axis Radiography for Hydrodynamic Testing (DARHT) facility at Los Alamos produces flash radiographs of large hydrodynamic experiments. Two linear induction accelerators (LIAs) make the bremsstrahlung radiographic source spots for orthogonal views of each test. The 2-kA, 20-MeV Axis-I LIA creates a single 60-ns radiography pulse. The 1.7-kA, 16.5-MeV Axis-II LIA creates up to four radiography pulses by kicking them out of a longer pulse that has a 1.6-{mu}s flattop. The Axis-II injector, LIA, kicker, and downstream transport (DST) to the bremsstrahlung converter are described. Adjusting the magnetic focusing and steering elements to optimize the electron-beam transport through an LIA is often called 'tuning.' As in all high-current LIAs, the focusing field is designed to be as close to that of the ideal continuous solenoid as physically possible. In ideal continuous solenoidal transport a smoothly varying beam size can easily be found for which radial forces balance, and the beam is said to be 'matched' to the focusing field. A 'mismatched' beam exhibits unwanted oscillations in size, which are a source of free energy that contributes to emittance growth. This is undesirable, because in the absence of beam-target effects, the radiographic spot size is proportional to the emittance. Tuning the Axis-II LIA is done in two steps. First, the solenoidal focusing elements are set to values designed to provide a matched beam with little or no envelope oscillations, and little or no beam-breakup (BBU) instability growth. Then, steering elements are adjusted to minimize the motion of the centroid of a well-centered beam at the LIA exit. This article only describes the design of the tune for the focusing solenoids. The DARHT Axis-II LIA was required to be re-tuned after installing an accelerator cell to replace a failed solenoid in March of 2012. We took advantage of this opportunity to improve the design of the focusing tune with better models of the remaining partially failed solenoids, better estimates of beam initial conditions, and better values for pulsed-power voltages. As with all previous tunes for Axis-II, this one incorporates measures to mitigate beam-breakup (BBU) instability, image displacement instability (IDI), corkscrew (sweep), and emittance growth. Section II covers the general approach to of design of focusing solenoid tunes for the DARHT Axis-2 LIA. Section III explains the specific requirements and simulations needed to design the tune for the injector, which includes the thermionic electron source, diode, and six induction cells. Section IV explains the requirements and simulations for tuning the main accelerator, which consists of 68 induction cells. Finally, Section V explores sensitivity of the tune to deviations of parameters from nominal, random variations, and uncertainties in values. Four appendices list solenoid settings for this new tune, discuss comparisons of different simulation codes, show halo formation in mismatched beams, and present a brief discussion of the beam envelope equation, which is the heart of the method used to design LIA solenoid tunes.

  1. A superconducting focusing solenoid for the neutrino factory linear accelerator

    E-Print Network [OSTI]

    Green, Michael A.; Lebedev, V.; Strauss, B.P.

    2001-01-01

    et al, “The Role of Superconductivity and Cryogenics in theA Superconducting Focusing Solenoid for the Neutrino FactoryAcceleration Cells for the Superconducting Linac. Shown in

  2. Calculations Pertaining to the Design ofa Prebuncher fora 150-MeV electron Linear Accelerator. 3. Comparisons with Experimental Data

    E-Print Network [OSTI]

    Alsmiller, R G Jr; Lewis, T A

    1985-01-01

    Calculations Pertaining to the Design ofa Prebuncher fora 150-MeV electron Linear Accelerator. 3. Comparisons with Experimental Data

  3. Transportation Channel with Uniform Electron Distribution for the Kharkov Neutron Source based on Subcritical Assembly Driven with Linear Accelerator

    E-Print Network [OSTI]

    Zelinsky, A Y

    2008-01-01

    Transportation Channel with Uniform Electron Distribution for the Kharkov Neutron Source based on Subcritical Assembly Driven with Linear Accelerator

  4. 20 MW Pulse Amplifier Klystron with Multiple Frequency Two-Gap Bunching Resonators for Linear Electron Accelerators

    E-Print Network [OSTI]

    Simonov, K G; Mamontov, A V

    2008-01-01

    20 MW Pulse Amplifier Klystron with Multiple Frequency Two-Gap Bunching Resonators for Linear Electron Accelerators

  5. Particle trajectories in linearized irrotational shallow water flows

    E-Print Network [OSTI]

    Delia Ionescu-Kruse

    2011-06-20

    We investigate the particle trajectories in an irrotational shallow water flow over a flat bed as periodic waves propagate on the water's free surface. Within the linear water wave theory, we show that there are no closed orbits for the water particles beneath the irrotational shallow water waves. Depending on the strength of underlying uniform current, we obtain that some particle trajectories are undulating path to the right or to the left, some are looping curves with a drift to the right and others are parabolic curves or curves which have only one loop.

  6. The Particle Accelerator Simulation Code PyORBIT

    SciTech Connect (OSTI)

    Gorlov, Timofey V [ORNL; Holmes, Jeffrey A [ORNL; Cousineau, Sarah M [ORNL; Shishlo, Andrei P [ORNL

    2015-01-01

    The particle accelerator simulation code PyORBIT is presented. The structure, implementation, history, parallel and simulation capabilities, and future development of the code are discussed. The PyORBIT code is a new implementation and extension of algorithms of the original ORBIT code that was developed for the Spallation Neutron Source accelerator at the Oak Ridge National Laboratory. The PyORBIT code has a two level structure. The upper level uses the Python programming language to control the flow of intensive calculations performed by the lower level code implemented in the C++ language. The parallel capabilities are based on MPI communications. The PyORBIT is an open source code accessible to the public through the Google Open Source Projects Hosting service.

  7. Proceedings of the 22nd Particle Accelerator Conference (PAC'07)

    SciTech Connect (OSTI)

    N /A

    2007-08-01

    The twenty-second Particle Accelerator Conference, PAC'07, took place at the Albuquerque Convention Centre in Albuquerque, the largest city in New Mexico, from Monday to Friday, 2007 June 25 to 29. It was attended by over 1350 delegates from 25 different countries (63% North America, 24% Europe, 11% Asia and 2% Other), and was held under the auspices of the two professional societies that oversee and make holding this series of conferences possible, the Division of Physics of Beams within APS, and the Nuclear and Plasma Sciences Society within IEEE. As host of the conference, Los Alamos National Laboratory (LANL) is especially thanked for their many contributions and assistance both prior to and during the conference. The Convention Center was an ideal location for information sharing and discussions between the interdisciplinary aspects of the accelerator community, as well as for related meetings and ad-hoc 'rump' sessions.

  8. Wave function of classical particle in linear potential

    E-Print Network [OSTI]

    A. S. Avanesov; V. I. Manko

    2013-04-03

    The problem of classical particle in linear potential is studied by using the formalism of Hilbert space and tomographic probability distribution. The Liouville equation for this problem is solved by finding the density matrix satisfying von Newmann-like equation in the form of product of wave functions. The relation to quantum mechanics is discussed.

  9. Linear water waves with vorticity: rotational features and particle paths

    E-Print Network [OSTI]

    Mats Ehrnstrom; Gabriele Villari

    2007-12-04

    Steady linear gravity waves of small amplitude travelling on a current of constant vorticity are found. For negative vorticity we show the appearance of internal waves and vortices, wherein the particle trajectories are not any more closed ellipses. For positive vorticity the situation resembles that of Stokes waves, but for large vorticity the trajectories are affected.

  10. uge particle accelerators have been at the vanguard of research in particle

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    of such machines -- for the LHC, a 27-km circum- ference and several billion euros -- are fuelling a serious effort counterparts, positrons, can then `surf' the electric field of a wave's wake. Particles have been accelerated- ting, radio-frequency electric field through long metallic cavities (around a metre long for medical

  11. Load Schedule Coordination for a Large Linear Accelerator: An Operation Powerplay Concept 

    E-Print Network [OSTI]

    Johnson, W. H.

    1984-01-01

    -power from Federal power projects, and the Los Alamos National Laboratory (LANL) at Los Alamos, New Mexico. With this variation, only the portion of LANL's total load requirement for the Linear Accelerator at the Meson Physics Facility is targeted...

  12. Proceedings of the Oak Ridge Electron Linear Accelerator (ORELA) Workshop

    SciTech Connect (OSTI)

    Dunn, M.E.

    2006-02-27

    The Oak Ridge National Laboratory (ORNL) organized a workshop at ORNL July 14-15, 2005, to highlight the unique measurement capabilities of the Oak Ridge Electron Linear Accelerator (ORELA) facility and to emphasize the important role of ORELA for performing differential cross-section measurements in the low-energy resonance region that is important for nuclear applications such as nuclear criticality safety, nuclear reactor and fuel cycle analysis, stockpile stewardship, weapons research, medical diagnosis, and nuclear astrophysics. The ORELA workshop (hereafter referred to as the Workshop) provided the opportunity to exchange ideas and information pertaining to nuclear cross-section measurements and their importance for nuclear applications from a variety of perspectives throughout the U.S. Department of Energy (DOE). Approximately 50 people, representing DOE, universities, and seven U.S. national laboratories, attended the Workshop. The objective of the Workshop was to emphasize the technical community endorsement for ORELA in meeting nuclear data challenges in the years to come. The Workshop further emphasized the need for a better understanding of the gaps in basic differential nuclear measurements and identified the efforts needed to return ORELA to a reliable functional measurement facility. To accomplish the Workshop objective, nuclear data experts from national laboratories and universities were invited to provide talks emphasizing the unique and vital role of the ORELA facility for addressing nuclear data needs. ORELA is operated on a full cost-recovery basis with no single sponsor providing complete base funding for the facility. Consequently, different programmatic sponsors benefit by receiving accurate cross-section data measurements at a reduced cost to their respective programs; however, leveraging support for a complex facility such as ORELA has a distinct disadvantage in that the programmatic funds are only used to support program-specific measurements. As a result, ORELA has not received base funding to support major upgrades and significant maintenance operations that are essential to keep the facility in a state of readiness over the long term. As a result, ORELA has operated on a ''sub-bare-minimum'' budget for the past 10 to 15 years, and the facility has not been maintained at a level for continued reliable operation for the long term. During the Workshop, Jerry McKamy (NNSA/NA-117) used a hospital patient metaphor that accurately depicts the facility status. ORELA is currently in the intensive care unit (ICU) on life support, and refurbishment efforts are needed to get the ''patient'' off life support and out to an ordinary hospital room. McKamy further noted that the DOE NCSP is planning to fund immediate refurbishment tasks ($1.5 M over three years) to help reestablish reliable ORELA operation (i.e., move ORELA from ICU to an ordinary hospital room). Furthermore, the NCSP will work to identify and carry out the actions needed to discharge ORELA from the ''hospital'' over the next five to seven years. In accordance with the Workshop objectives, the technical community publicly endorsed the need for a reliable ORELA facility that can meet current and future nuclear data needs. These Workshop proceedings provide the formal documentation of the technical community endorsement for ORELA. Furthermore, the proceedings highlight the past and current contributions that ORELA has made to the nuclear industry. The Workshop further emphasized the operational and funding problems that currently plague the facility, thereby limiting ORELA's operational reliability. Despite the recent operational problems, ORELA is a uniquely capable measurement facility that must be part of the overall U.S. nuclear data measurement portfolio in order to support current and emerging nuclear applications. The Workshop proceedings further emphasize that ORNL, the technical community, and programmatic sponsors are eager to see ORELA reestablish reliable measurement operation and be readily available to address nuclear data challe

  13. Particle Acceleration and Magnetic Field Generation in Electron-Positron Relativistic Shocks

    E-Print Network [OSTI]

    K. -I. Nishikawa; P. Hardee; G. Richardson; R. Preece; H. Sol; G. J. Fishman

    2004-12-10

    Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., Buneman, Weibel and other two-stream instabilities) created in collisionless shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic electron-positron jet front propagating into an ambient electron-positron plasma with and without initial magnetic fields. We find small differences in the results for no ambient and modest ambient magnetic fields. New simulations show that the Weibel instability created in the collisionless shock front accelerates jet and ambient particles both perpendicular and parallel to the jet propagation direction. Furthermore, the non-linear fluctuation amplitudes of densities, currents, electric, and magnetic fields in the electron-positron shock are larger than those found in the electron-ion shock studied in a previous paper at the comparable simulation time. This comes from the fact that both electrons and positrons contribute to generation of the Weibel instability. Additionally, we have performed simulations with different electron skin depths. We find that growth times scale inversely with the plasma frequency, and the sizes of structures created by the Weibel instability scale proportional to the electron skin depth. This is the expected result and indicates that the simulations have sufficient grid resolution. The simulation results show that the Weibel instability is responsible for generating and amplifying nonuniform, small-scale magnetic fields which contribute to the electron's (positron's) transverse deflection behind the jet head.

  14. Photoelectron linear accelerator for producing a low emittance polarized electron beam

    DOE Patents [OSTI]

    Yu, David U.; Clendenin, James E.; Kirby, Robert E.

    2004-06-01

    A photoelectron linear accelerator for producing a low emittance polarized electric beam. The accelerator includes a tube having an inner wall, the inner tube wall being coated by a getter material. A portable, or demountable, cathode plug is mounted within said tube, the surface of said cathode having a semiconductor material formed thereon.

  15. Query-driven Analysis of Plasma-based Particle Acceleration Data Oliver Rubel

    E-Print Network [OSTI]

    Query-driven Analysis of Plasma-based Particle Acceleration Data Oliver R¨ubel LBNL Cameron G. R Laboratory, e-mail: {oruebel, ewbethel}@lbl.gov Laser, Optical Accelerator System Integrated Studies (LOASIS INTRODUCTION Plasma-based particle accelerators utilize an electron plasma wave driven by a short ( 100 fs

  16. Estimation of direct laser acceleration in laser wakefield accelerators using particle-in-cell simulations

    E-Print Network [OSTI]

    Shaw, J L; Marsh, K A; Tsung, F S; Mori, W B; Joshi, C

    2015-01-01

    Many current laser wakefield acceleration (LWFA) experiments are carried out in a regime where the laser pulse length is on the order of or longer than the wake wavelength and where ionization injection is employed to inject electrons into the wake. In these experiments, the trapped electrons will co-propagate with the longitudinal wakefield and the transverse laser field. In this scenario, the electrons can gain a significant amount of energy from both the direct laser acceleration (DLA) mechanism as well as the usual LWFA mechanism. Particle-in-cell (PIC) codes are frequently used to discern the relative contribution of these two mechanisms. However, if the longitudinal resolution used in the PIC simulations is inadequate, it can produce numerical heating that can overestimate the transverse motion, which is important in determining the energy gain due to DLA. We have therefore carried out a systematic study of this LWFA regime by varying the longitudinal resolution of PIC simulations from the standard, bes...

  17. Feature-based Analysis of Plasma-based Particle Acceleration Data

    SciTech Connect (OSTI)

    Ruebel, Oliver; Geddes, Cameron G.R.; Chen, Min; Cormier-Michel, Estelle; Bethel, E. Wes

    2013-07-05

    Plasma-based particle accelerators can produce and sustain thousands of times stronger acceleration fields than conventional particle accelerators, providing a potential solution to the problem of the growing size and cost of conventional particle accelerators. To facilitate scientific knowledge discovery from the ever growing collections of accelerator simulation data generated by accelerator physicists to investigate next-generation plasma-based particle accelerator designs, we describe a novel approach for automatic detection and classification of particle beams and beam substructures due to temporal differences in the acceleration process, here called acceleration features. The automatic feature detection in combination with a novel visualization tool for fast, intuitive, query-based exploration of acceleration features enables an effective top-down data exploration process, starting from a high-level, feature-based view down to the level of individual particles. We describe the application of our analysis in practice to analyze simulations of single pulse and dual and triple colliding pulse accelerator designs, and to study the formation and evolution of particle beams, to compare substructures of a beam and to investigate transverse particle loss.

  18. Cryogenic system for the MYRRHA superconducting linear accelerator

    SciTech Connect (OSTI)

    Chevalier, Nicolas R.; Junquera, Tomas; Thermeau, Jean-Pierre; Romão, Luis Medeiros; Vandeplassche, Dirk

    2014-01-29

    SCK?CEN, the Belgian Nuclear Research Centre, is designing MYRRHA, a flexible fast spectrum research reactor (80 MW{sub th}), conceived as an accelerator driven system (ADS), able to operate in sub-critical and critical modes. It contains a continuous-wave (CW) superconducting (SC) proton accelerator of 600 MeV, a spallation target and a multiplying core with MOX fuel, cooled by liquid lead-bismuth (Pb-Bi). From 17 MeV onward, the SC accelerator will consist of 48 ?=0.36 spoke-loaded cavities (352 MHz), 34 ?=0.47 elliptical cavities (704 MHz) and 60 ?=0.65 elliptical cavities (704 MHz). We present an analysis of the thermal loads and of the optimal operating temperature of the cryogenic system. In particular, the low operating frequency of spoke cavities makes their operation in CW mode possible both at 4.2 K or at 2 K. Our analysis outlines the main factors that determine at what temperature the spoke cavities should be operated. We then present different cryogenic fluid distribution schemes, important characteristics (storage, transfer line, etc.) and the main challenges offered by MYRRHA in terms of cryogenics.

  19. SINGLE CRYSTAL NIOBIUM TUBES FOR PARTICLE COLLIDERS ACCELERATOR CAVITIES

    SciTech Connect (OSTI)

    MURPHY, JAMES E

    2013-02-28

    The objective of this research project is to produce single crystal niobium (Nb) tubes for use as particle accelerator cavities for the Fermi laboratory’s International Linear Collider project. Single crystal Nb tubes may have superior performance compared to a polycrystalline tubes because the absence of grain boundaries may permit the use of higher accelerating voltages. In addition, Nb tubes that are subjected to the high temperature, high vacuum crystallization process are very pure and well annealed. Any impurity with a significantly higher vapor pressure than Nb should be decreased by the relatively long exposure at high temperature to the high vacuum environment. After application of the single crystal process, the surfaces of the Nb tubes are bright and shiny, and the tube resembles an electro polished Nb tube. For these reasons, there is interest in single crystal Nb tubes and in a process that will produce single crystal tubes. To convert a polycrystalline niobium tube into a single crystal, the tube is heated to within a few hundred ?C of the melting temperature of niobium, which is 2477 ?C. RF heating is used to rapidly heat the tube in a narrow zone and after reaching the operating temperature, the hot zone is slowly passed along the length of the tube. For crystallization tests with Nb tubes, the traverse rate was in the range of 1-10 cm per hour. All the crystallization tests in this study were performed in a water-cooled, stainless steel chamber under a vacuum of 5 x10-6 torr or better. In earliest tests of the single crystal growth process, the Nb tubes had an OD of 1.9 cm and a wall thickness of 0.15 mm. With these relatively small Nb tubes, the single crystal process was always successful in producing single crystal tubes. In these early tests, the operating temperature was normally maintained at 2200 ?C, and the traverse rate was 5 cm per hour. In the next test series, the Nb tube size was increased to 3.8 cm OD and the wall thickness was increased 0.18 mm and eventually to 0.21 mm. Again, with these larger tubes, single crystal tubes were usually produced by the crystallization process. The power supply was generally operated at full output during these tests, and the traverse rate was 5 cm per hour. In a few tests, the traverse rate was increased to 10 cm per hour, and at the faster traverse rate, single crystal growth was not achieved. In these tests with a faster traverse rate, it was thought that the tube was not heated to a high enough temperature to achieve single crystal growth. In the next series of tests, the tube OD was unchanged at 3.8 cm and the wall thickness was increased to 0.30 mm. The increased wall thickness made it difficult to reach an operating temperature above 2,000 ?C, and although the single crystal process caused a large increase in the crystal grains, no single crystal tubes were produced. It was assumed that the operating temperature in these tests was not high enough to achieve single crystal growth. In FY 2012, a larger power supply was purchased and installed. With the new power supply, temperatures above the melting point of Nb were easily obtained regardless of the tube thickness. A series of crystallization tests was initiated to determine if indeed the operating temperature of the previous tests was too low to achieve single crystal growth. For these tests, the Nb tube OD remained at 3.8 cm and the wall thickness was 0.30 mm. The first test had an operating temperature of 2,000 ?C. and the operating temperature was increased by 50 ?C increments for each successive test. The final test was very near the Nb melting temperature, and indeed, the Nb tube eventually melted in the center of the tube. These tests showed that higher temperatures did yield larger grain sizes if the traverse rate was held constant at 5 cm per hour, but no single crystal tubes were produced even at the highest operating temperature. In addition, slowing the traverse rate to as low as 1 cm per hour did not yield a single crystal tube regardless of operating temperature. At this time, it

  20. The Mysterious Universe - Exploring Our World with Particle Accelerators

    ScienceCinema (OSTI)

    Brau, James E [University of Oregon

    2014-06-25

    The universe is dark and mysterious, more so than even Einstein imagined. While modern science has established deep understanding of ordinary matter, unidentified elements ("Dark Matter" and "Dark Energy") dominate the structure of the universe, its behavior and its destiny. What are these curious elements? We are now working on answers to these and other challenging questions posed by the universe with experiments at particle accelerators on Earth. Results of this research may revolutionize our view of nature as dramatically as the advances of Einstein and other quantum pioneers one hundred years ago. Professor Brau will explain for the general audience the mysteries, introduce facilities which explore them experimentally and discuss our current understanding of the underlying science. The presentation is at an introductory level, appropriate for anyone interested in physics and astronomy.

  1. Black hole lightning due to particle acceleration at subhorizon scales

    E-Print Network [OSTI]

    Aleksi?, J; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; Barrio, J A; González, J Becerra; Bednarek, W; Bernardini, E; Biasuzzi, B; Biland, A; Blanch, O; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Colin, P; Colombo, E; Contreras, J L; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; Wilhelmi, E de Oña; Mendez, C Delgado; Prester, D Dominis; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; Galindo, D; López, R J García; Garczarczyk, M; Terrats, D Garrido; Gaug, M; Godinovi?, N; Muñoz, A González; Gozzini, S R; Hadasch, D; Hanabata, Y; Hayashida, M; Herrera, J; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Kadenius, V; Kellermann, H; Kodani, K; Konno, Y; Krause, J; Kubo, H; Kushida, J; La Barbera, A; Lelas, D; Lewandowska, N; Lindfors, E; Lombardi, S; Longo, F; López, M; López-Coto, R; López-Oramas, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martínez, M; Mazin, D; Menzel, U; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Niedzwiecki, A; Nilsson, K; Nishijima, K; Noda, K; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Persic, M; Poutanen, J; Moroni, P G Prada; Prandini, E; Puljak, I; Reinthal, R; Rhode, W; Ribó, M; Rico, J; Garcia, J Rodriguez; Rügamer, S; Saito, T; Saito, K; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schweizer, T; Shore, S N; Sillanpää, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamatescu, V; Stamerra, A; Steinbring, T; Storz, J; Strzys, M; Takalo, L; Takami, H; Tavecchio, F; Temnikov, P; Terzi?, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Uellenbeck, M; Vogler, P; Zanin, R; Kadler, M; Schulz, R; Ros, E; Bach, U; Krauß, F; Wilms, J

    2014-01-01

    Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry, but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here, we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC telescopes revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20\\% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet.

  2. Particle injection and cosmic ray acceleration at collisionless parallel shocks

    SciTech Connect (OSTI)

    Quest, K.B.

    1987-01-01

    The structure of collisionless parallel shocks is studied using one-dimensional hybrid simulations, with emphasis on particle injection into the first-order Fermi acceleration process. It is argued that for sufficiently high Mach number shocks, and in the absence of wave turbulence, the fluid firehose marginal stability condition will be exceeded at the interface between the upstream, unshocked, plasma and the heated plasma downstream. As a consequence, nonlinear, low-frequency, electromagnetic waves are generated and act to slow the plasma and provide dissipation for the shock. It is shown that large amplitude waves at the shock ramp scatter a small fraction of the upstream ions back into the upstream medium. These ions, in turn, resonantly generate the electromagnetic waves that are swept back into the shock. As these waves propagate through the shock they are compressed and amplified, allowing them to non-resonantly scatter the bulk of the plasma. Moreover, the compressed waves back-scatter a small fraction of the upstream ions, maintaining the shock structure in a quasi-steady state. The back-scattered ions are accelerated during the wave generation process to 2 to 4 times the ram energy and provide a likely seed population for cosmic rays. 49 refs., 7 figs.

  3. Photo of the Week: What Does a Particle Accelerator Have in Common...

    Broader source: Energy.gov (indexed) [DOE]

    could be widely used in medicine and industry -- particle accelerators are used for cancer research, processing computer chips, and even producing the shrink wrap used to keep...

  4. A complete cosmic scenario from inflation to late time acceleration: Non-equilibrium thermodynamics in the context of particle creation

    E-Print Network [OSTI]

    Subenoy Chakraborty; Subhajit Saha

    2015-07-06

    The paper deals with the mechanism of particle creation in the framework of irreversible thermodynamics. The second order non-equilibrium thermodynamical prescription of Israel and Stewart has been presented with particle creation rate, treated as the dissipative effect. In the background of a flat FRW model, we assume the non-equilibrium thermodynamical process to be isentropic so that the entropy per particle does not change and consequently the dissipative pressure can be expressed linearly in terms of the particle creation rate. Here the dissipative pressure behaves as a dynamical variable having a non-linear inhomogeneous evolution equation and the entropy flow vector satisfies the second law of thermodynamics. Further, using the Friedmann equations and by proper choice of the particle creation rate as a function of the Hubble parameter, it is possible to show (separately) a transition from the inflationary phase to the radiation era and also from matter dominated era to late time acceleration. Also, in analogy to analytic continuation, it is possible to show a continuous cosmic evolution from inflation to late time acceleration by adjusting the parameters. It is found that in the de Sitter phase, the comoving entropy increases exponentially with time, keeping entropy per particle unchanged. Subsequently, the above cosmological scenarios has been described from field theoretic point of view by introducing a scalar field having self interacting potential. Finally, we make an attempt to show the cosmological phenomenon of particle creation as Hawking radiation, particularly during the inflationary era.

  5. Spectra of accelerated particles at supernova shocks in the presence of neutral hydrogen: the case of Tycho

    E-Print Network [OSTI]

    Morlino, G

    2015-01-01

    The presence of neutral hydrogen in the shock proximity changes the structure of the shock and affects the spectra of particles accelerated through the first order Fermi mechanism. This phenomenon has profound implications for the interpretation of the multifrequency spectra of radiation from supernova remnants. Neutrals that undergo charge exchange with hot ions downstream of the shock may result in fast neutrals moving towards the upstream gas, where they can suffer additional charge exchange or ionisation reactions, thereby depositing energy and momentum upstream. Here we discuss the implications of this neutral return flux, already predicted in our previous work on neutral mediated supernova shocks and show how the spectra of accelerated particles turn out to be appreciably steeper than $p^{-4}$, thereby affecting the gamma ray spectra from supernova remnants in general and from Tycho specifically. The theory that describes non-linear diffusive shock acceleration in the presence of neutral hydrogen has be...

  6. Fundamentals of Non-relativistic Collisionless Shock Physics: V. Acceleration of Charged Particles

    E-Print Network [OSTI]

    R. A. Treumann; C. H. Jaroschek

    2008-06-25

    A comprehensive review is given of the various processes proposed for accelerating particles by shocks to high energies. These energies are limited by several bounds: the non-relativistic nature of the heliospheric collisionless shocks to which this review restricts, the finite size of these shocks, the finite width of the downstream region, and to the nature of turbulence. In general, collisionless shocks in the heliosphere cannot accelerate particles to very high energies. As a fundamental problem of the acceleration mechanism the injection of see particles is identified. Some mecchanisms for production of seed particles are invoked. Acceleration of electrons begins to uncover its nature. The following problems are covered in this chapter: 1. Introduction -- first and second order Fermi acceleration, 2. Accelerating ions when they are already fast, diffusive acceleration, convection diffusion equation, Lee's self-consistent quasilinear shock acceleration model, 3. Observations, 4. The injection problem, ion surfing, test particle simulations, self-consistent shock acceleration simulations, downstream leakage, trapped particle acceleration, 5. Accelerating electrons, Sonnerup-Wu mechanism, Hoshino's electron shock surfing on quasi-perpendicular shocks, quasiparallel shock surfing.

  7. Diagnostic resonant cavity for a charged particle accelerator

    DOE Patents [OSTI]

    Barov, Nikolai (San Diego, CA)

    2007-10-02

    Disclosed is a diagnostic resonant cavity for determining characteristics of a charged particle beam, such as an electron beam, produced in a charged particle accelerator. The cavity is based on resonant quadrupole-mode and higher order cavities. Enhanced shunt impedance in such cavities is obtained by the incorporation of a set of four or more electrically conductive rods extending inwardly from either one or both of the end walls of the cavity, so as to form capacitive gaps near the outer radius of the beam tube. For typical diagnostic cavity applications, a five-fold increase in shunt impedance can be obtained. In alternative embodiments the cavity may include either four or more opposing pairs of rods which extend coaxially toward one another from the opposite end walls of the cavity and are spaced from one another to form capacitative gaps; or the cavity may include a single set of individual rods that extend from one end wall to a point adjacent the opposing end wall.

  8. Technical Challenges and Scientific Payoffs of Muon Beam Accelerators for Particle Physics

    E-Print Network [OSTI]

    Zisman, Michael S.

    2008-01-01

    and O. Yasuda (eds. ), “Physics at a future neutrino factoryAccelerators for Particle Physics Michael S. Zisman trendP HYSICS Q UESTIONS Particle physics is a broad subject, and

  9. Generalized linear Boltzmann equations for particle transport in polycrystals

    E-Print Network [OSTI]

    Jens Marklof; Andreas Strömbergsson

    2015-02-13

    The linear Boltzmann equation describes the macroscopic transport of a gas of non-interacting point particles in low-density matter. It has wide-ranging applications, including neutron transport, radiative transfer, semiconductors and ocean wave scattering. Recent research shows that the equation fails in highly-correlated media, where the distribution of free path lengths is non-exponential. We investigate this phenomenon in the case of polycrystals whose typical grain size is comparable to the mean free path length. Our principal result is a new generalized linear Boltzmann equation that captures the long-range memory effects in this setting. A key feature is that the distribution of free path lengths has an exponential decay rate, as opposed to a power-law distribution observed in a single crystal.

  10. Study of the electronics architecture for the mechanical stabilisation of the quadrupoles of the CLIC linear accelerator

    E-Print Network [OSTI]

    Artoos, K; Fernandez Carmona, P; Guinchard, M; Hauviller, C; Janssens, S; Kuzmin, A; Slaathaug, A

    2010-01-01

    To reach a sufficient luminosity, the transverse beam sizes and emittances in future linear particle accelerators should be reduced to the nanometer level. Mechanical stabilisation of the quadrupole magnets is of the utmost importance for this. The piezo actuators used for this purpose can also be used to make fast incremental orientation adjustments with a nanometer resolution. The main requirements for the CLIC stabilisation electronics is a robust, low noise, low delay, high accuracy and resolution, low band and radiation resistant feedback control loop. Due to the high number of controllers (about 4000) a cost optimization should also be made. Different architectures are evaluated for a magnet stabilisation prototype, including the sensors type and configuration, partition between software and hardware for control algorithms, and optimization of the ADC/DAC converters. The controllers will be distributed along the 50 km long accelerator and a communication bus should allow external control. Furthermore, o...

  11. E-157: A 1.4-m-long plasma wake field acceleration experiment using a 30 GeV electron beam from the Stanford Linear Accelerator

    E-Print Network [OSTI]

    conducted at the Stanford Linear Accelerator Center, a 30 GeV electron beam of 2 1010 electrons in a 0.65-mmE-157: A 1.4-m-long plasma wake field acceleration experiment using a 30 GeV electron beam from the Stanford Linear Accelerator Center Linac* M. J. Hogan, R. Assmann,a) F.-J. Decker, R. Iverson, P. Raimondi

  12. Motivations Particle Swarm Optimisation PSO Aided Linear MUT PSO Aided Nonlinear MUT Conclusions Particle Swarm Optimisation Aided Multiuser

    E-Print Network [OSTI]

    Chen, Sheng

    Motivations Particle Swarm Optimisation PSO Aided Linear MUT PSO Aided Nonlinear MUT Conclusions Processing #12;Motivations Particle Swarm Optimisation PSO Aided Linear MUT PSO Aided Nonlinear MUT Conclusions Outline 1 Motivations Bio-Inspired Computation Our Novelty 2 Particle Swarm Optimisation PSO

  13. Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers

    DOE Patents [OSTI]

    Danby, G.T.; Jackson, J.W.

    1990-03-19

    A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations (dB/dt) in the particle beam.

  14. Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers

    DOE Patents [OSTI]

    Danby, Gordon T. (Wading River, NY); Jackson, John W. (Shoreham, NY)

    1991-01-01

    A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations in the particle beam.

  15. Non-thermal electron acceleration in low Mach number collisionless shocks. I. Particle energy spectra and acceleration mechanism

    SciTech Connect (OSTI)

    Guo, Xinyi; Narayan, Ramesh; Sironi, Lorenzo

    2014-10-20

    Electron acceleration to non-thermal energies in low Mach number (M{sub s} ? 5) shocks is revealed by radio and X-ray observations of galaxy clusters and solar flares, but the electron acceleration mechanism remains poorly understood. Diffusive shock acceleration, also known as first-order Fermi acceleration, cannot be directly invoked to explain the acceleration of electrons. Rather, an additional mechanism is required to pre-accelerate the electrons from thermal to supra-thermal energies, so they can then participate in the Fermi process. In this work, we use two- and three-dimensional particle-in-cell plasma simulations to study electron acceleration in low Mach number shocks. We focus on the particle energy spectra and the acceleration mechanism in a reference run with M{sub s} = 3 and a quasi-perpendicular pre-shock magnetic field. We find that about 15% of the electrons can be efficiently accelerated, forming a non-thermal power-law tail in the energy spectrum with a slope of p ? 2.4. Initially, thermal electrons are energized at the shock front via shock drift acceleration (SDA). The accelerated electrons are then reflected back upstream where their interaction with the incoming flow generates magnetic waves. In turn, the waves scatter the electrons propagating upstream back toward the shock for further energization via SDA. In summary, the self-generated waves allow for repeated cycles of SDA, similarly to a sustained Fermi-like process. This mechanism offers a natural solution to the conflict between the bright radio synchrotron emission observed from the outskirts of galaxy clusters and the low electron acceleration efficiency usually expected in low Mach number shocks.

  16. PARTICLE ACCELERATION AT QUASI-PARALLEL SHOCK WAVES: THEORY AND OBSERVATIONS AT 1 AU

    SciTech Connect (OSTI)

    Neergaard Parker, L.; Zank, G. P.

    2012-09-20

    In this paper, we describe a theoretical model for accelerating an arbitrary upstream particle distribution. Only those particles that exceed a prescribed injection energy, E{sub inj}, are accelerated via the diffusive shock acceleration (DSA) mechanism, also known as first-order Fermi acceleration. We identify a set of quasi-parallel shocks at 1 AU and use the observed solar wind particle distribution information to construct our upstream distribution, which is then accelerated diffusively at the shock, assuming the observed shock parameters. The injection energy for particles to be accelerated diffusively at a quasi-parallel shock is discussed theoretically. By using the observed upstream solar wind distribution function and the observed shock parameters, we can compute the injection energy that matches the observed downstream accelerated particle spectrum. Like the previous studies of van Nes et al., Lario et al., and Ho et al., this analysis focuses on the acceleration of protons only via the first-order Fermi acceleration mechanism. However, our primary focus is on quasi-parallel shocks and the injection mechanism in the context of DSA with a background thermal solar wind modeled as a Maxwellian or kappa distribution. Our approach allows for a direct test of injection at interplanetary shocks. It has been proposed that an additional seed population of energetic particles is needed to explain the accelerated particle distribution downstream of quasi-parallel shocks. This conclusion is based typically on studies that address the acceleration of heavy ions primarily and do not characterize the injection of protons alone using the DSA mechanism. Through comparisons of Maxwellian and kappa upstream distributions, we find that DSA with injection directly from a thermal Maxwellian distribution, or weak departures therefrom, for protons is responsible for energetic solar particle events associated with quasi-parallel shocks.

  17. Effect of polarization and focusing on laser pulse driven auto-resonant particle acceleration

    SciTech Connect (OSTI)

    Sagar, Vikram; Sengupta, Sudip; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar-382428 (India)] [Institute for Plasma Research, Bhat, Gandhinagar-382428 (India)

    2014-04-15

    The effect of laser polarization and focusing is theoretically studied on the final energy gain of a particle in the Auto-resonant acceleration scheme using a finite duration laser pulse with Gaussian shaped temporal envelope. The exact expressions for dynamical variables viz. position, momentum, and energy are obtained by analytically solving the relativistic equation of motion describing particle dynamics in the combined field of an elliptically polarized finite duration pulse and homogeneous static axial magnetic field. From the solutions, it is shown that for a given set of laser parameters viz. intensity and pulse length along with static magnetic field, the energy gain by a positively charged particle is maximum for a right circularly polarized laser pulse. Further, a new scheme is proposed for particle acceleration by subjecting it to the combined field of a focused finite duration laser pulse and static axial magnetic field. In this scheme, the particle is initially accelerated by the focused laser field, which drives the non-resonant particle to second stage of acceleration by cyclotron Auto-resonance. The new scheme is found to be efficient over two individual schemes, i.e., auto-resonant acceleration and direct acceleration by focused laser field, as significant particle acceleration can be achieved at one order lesser values of static axial magnetic field and laser intensity.

  18. Proposed structure for a crossed-laser beam, GeV per meter gradient, vacuum electron linear accelerator

    E-Print Network [OSTI]

    Byer, Robert L.

    Proposed structure for a crossed-laser beam, GeV per meter gradient, vacuum electron linear We propose a dielectric-based, multistaged, laser-driven electron linear accelerator structure operating in a vacuum that is capable of accelerating electrons to 1 TeV in 1 km. Our study shows that a Ge

  19. Grad student aims to improve particle accelerators > EMC2 News...

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

    is a negatively charged electrode, that when hit with a laser light source, causes electrons to become excited and emitted from the electrode. The electrons are then accelerated...

  20. New Science on the Horizon as Upgraded Particle Accelerator Meets...

    Office of Science (SC) Website

    a new experimental area, Hall D. The Impact Researchers need very big microscopes to study the very small building blocks of matter. CEBAF's electron accelerator and...

  1. Use of a Linear Paul Trap to Study Random Noise-Induced Beam Degradation in High-Intensity Accelerators

    E-Print Network [OSTI]

    Gilson, Erik

    -Intensity Accelerators Moses Chung* Accelerator Physics Center, Fermi National Accelerator Laboratory, Batavia, Illinois equivalence between an alternating-gradient (AG) focusing system and a linear Paul trap system. It is observed that externally driven noise continuously produces a nonthermal tail of trapped ions

  2. Investigation of Propagation Characteristics of Twisted Hollow Waveguides for Particle Accelerator Applications

    SciTech Connect (OSTI)

    Wilson, Joshua L

    2008-09-01

    A new class of accelerating structures employing a uniformly twisted waveguide is investigated. Twisted waveguides of various cross-sectional geometries are considered and analyzed. It is shown that such a twisted waveguide can support waves that travel at a speed slower than the speed of light c. The slow-wave properties of twisted structures are of interest because these slow-wave electromagnetic fields can be used in applications such as electron traveling wave tubes and linear particle accelerators. Since there is no exact closed form solution for the electromagnetic fields within a twisted waveguide or cavity, several previously proposed approximate methods are examined, and more effcient approaches are developed. It is found that the existing perturbation theory methods yield adequate results for slowly twisted structures; however, our efforts here are geared toward analyzing rapidly twisted structures using modifed finite difference methods specially suited for twisted structures. Although the method can handle general twisted structures, three particular cross sections are selected as representative cases for careful analysis. First, a slowly twisted rectangular cavity is analyzed as a reference case. This is because its shape is simple and perturbation theory already gives a good approximate solution for such slow twists rates. Secondly, a symmetrically notched circular cross section is investigated, since its longitudinal cross section is comparable to the well known disk-loaded cavity (used in many practical accelerator designs, including SLAC). Finally, a "dumbbell" shaped cross section is analyzed because of its similarity to the well-known TESLA-type accelerating cavity, which is of great importance because of its wide acceptance as a superconducting cavity. To validate the results of the developed theory and our extensive simulations, the newly developed numerical models are compared to commercial codes. Also, several prototypes are developed employing the three basic shapes discussed previously. Bench measurements are performed on the prototype cavities to evaluate dispersion by measuring the field distribution along these cavities. The measurement results are compared to the simulations and theoretical results, and good agreement is shown. Once validated, the developed models are used to design twisted accelerating structures with specific phase velocities and good accelerating performance.

  3. Electromagnetic field-computation for particle accelerators, today and tomorrow

    SciTech Connect (OSTI)

    Turner, L.R.; Kettunen, L.

    1991-01-01

    In this paper, we first review the magnets needed in accelerators, then discuss computations for accelerator magnets performed with present codes, and finally describe a new volume integral code which shows promise, and should be suitable for parallel computation. 9 refs., 10 figs.

  4. Linear Accelerator

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesse BergkampCenter (LMI-EFRC) ProximityCenterLee Faculty

  5. Electron acceleration by linearly polarized twisted laser pulse with narrow divergence

    SciTech Connect (OSTI)

    Vaziri, Mohammad Sohaily, Sozha; Golshani, Mojtaba; Bahrampour, Alireza

    2015-03-15

    We numerically investigate the vacuum electron acceleration by a high-intensity linearly polarized twisted laser pulse. It is shown that the inherent spiral structure of a Laguerre-Gaussian laser pulse leads to improvement in trapping and acceleration of an electron to energies of the order of GeV in the off-axis case. Also, it is demonstrated that by employing a proper choice of initial injection parameters, the high-energetic electrons with very small scattering angles can be produced.

  6. APT related papers presented at the 1997 particle accelerator conference, Vancouver, May 12--16, 1997

    SciTech Connect (OSTI)

    Lawrence, G. [comp.

    1997-07-01

    Tritium is essential for the US nuclear weapons to function, but because it is radioactive with a half-life of 12.3 years, the supply must be periodically replenished. Presently, only reactor or accelerator systems can be used to produce tritium. This report is a compilation of 31 papers given at the 1997 Particle Accelerator Conference which dealt with the accelerator production of tritium. The papers are grouped into two categories, invited and contributed.

  7. Proceedings of the conference on computer codes and the linear accelerator community

    SciTech Connect (OSTI)

    Cooper, R.K. (comp.)

    1990-07-01

    The conference whose proceedings you are reading was envisioned as the second in a series, the first having been held in San Diego in January 1988. The intended participants were those people who are actively involved in writing and applying computer codes for the solution of problems related to the design and construction of linear accelerators. The first conference reviewed many of the codes both extant and under development. This second conference provided an opportunity to update the status of those codes, and to provide a forum in which emerging new 3D codes could be described and discussed. The afternoon poster session on the second day of the conference provided an opportunity for extended discussion. All in all, this conference was felt to be quite a useful interchange of ideas and developments in the field of 3D calculations, parallel computation, higher-order optics calculations, and code documentation and maintenance for the linear accelerator community. A third conference is planned.

  8. A Phenomenological Cost Model for High Energy Particle Accelerators

    E-Print Network [OSTI]

    Vladimir Shiltsev

    2014-04-15

    Accelerator-based high-energy physics have been in the forefront of scientific discoveries for more than half a century. The accelerator technology of the colliders has progressed immensely, while the beam energy, luminosity, facility size, and cost have grown by several orders of magnitude. The method of colliding beams has not fully exhausted its potential but has slowed down considerably in its progress. In this paper we derive a simple scaling model for the cost of large accelerators and colliding beam facilities based on costs of 17 big facilities which have been either built or carefully estimated. Although this approach cannot replace an actual cost estimate based on an engineering design, this parameterization is to indicate a somewhat realistic cost range for consideration of what future frontier accelerator facilities might be fiscally realizable.

  9. Orbit correction in a linear nonscaling fixed field alternating gradient accelerator

    SciTech Connect (OSTI)

    Kelliher, D. J.; Machida, S.; Edmonds, C. S.; Kirkman, I. W.; Jones, J. K.; Muratori, B. D.; Garland, J. M.; Berg, J. S.

    2014-11-01

    In a linear non-scaling FFAG the large natural chromaticity of the machine results in a betatron tune that varies by several integers over the momentum range. Orbit correction is complicated by the consequent variation of the phase advance between lattice elements. Here we investigate how the correction of multiple closed orbit harmonics allows correction of both the COD and the accelerated orbit distortion over the momentum range.

  10. Quasi-linear heating and acceleration in bi-Maxwellian plasmas

    SciTech Connect (OSTI)

    Hellinger, Petr; Trávní?ek, Pavel M.

    2013-12-15

    Quasi-linear acceleration and heating rates are derived for drifting bi-Maxwellian distribution functions in a general nonrelativistic case for arbitrary wave vectors, propagation angles, and growth/damping rates. The heating rates in a proton-electron plasma due to ion-cyclotron/kinetic Alfvén and mirror waves for a wide range of wavelengths, directions of propagation, and growth or damping rates are explicitly computed.

  11. Orbit correction in a linear nonscaling fixed field alternating gradient accelerator

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

    Kelliher, D. J.; Machida, S.; Edmonds, C. S.; Kirkman, I. W.; Jones, J. K.; Muratori, B. D.; Garland, J. M.; Berg, J. S.

    2014-11-20

    In a linear non-scaling FFAG the large natural chromaticity of the machine results in a betatron tune that varies by several integers over the momentum range. In addition, orbit correction is complicated by the consequent variation of the phase advance between lattice elements. Here we investigate how the correction of multiple closed orbit harmonics allows correction of both the COD and the accelerated orbit distortion over the momentum range.

  12. Accelerator and detector prospects of elementary particle A. N. Skrinskii

    E-Print Network [OSTI]

    McDonald, Kirk

    of methods of cooling charged-particle beams, preparation for serious application of super- conducting with colliding beams involving the development of methods of cooling charged-particle beams, designing) Electrons 1)Positrons m) Photons n) Muons o) Neutrinos Colliding 647 5. The "proton klystron" 650 6. The V I

  13. Accelerators | Photon Science | Particle Physics Deutsches Elektronen-Synchrotron

    E-Print Network [OSTI]

    of innovative concepts and techniques for the diagnostics of high-quality laser and electron beams · Perform program at PITZ is the: · ultimate optimization of high brightness electron beams by generating 3D ellipsoidal electron bunches, and · beam driven plasma acceleration experiments on the self

  14. Relativistic-Klystron two-beam accelerator as a power source for future linear colliders

    SciTech Connect (OSTI)

    Lidia, S. M.; Anderson, D. E.; Eylon, S.; Henestroza, E.; Vanecek, D. L.; Yu, S. S. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Houck, T. L.; Westenskow, G. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    1999-05-07

    The technical challenge for making two-beam accelerators into realizable power sources for high-energy colliders lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2-kA, 1-MeV, induction gun for a prototype relativistic klystron two-beam accelerator (RK-TBA). The electron source will be a 8.9 cm diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150-ns flat top (1% energy variation), and a normalized edge emittance of less than 300 pi-mm-mr. The prototype accelerator will be used to study, physics, engineering, and costing issues involved in the application of the RK-TBA concept to linear colliders. We have also been studying optimization parameters, such as frequency, for the application of the RK-TBA concept to multi-TeV linear colliders. As an rf power source the RK-TBA scales favorably up to frequencies around 35 GHz. An overview of this work with details of the design and performance of the prototype injector, beam line, and diagnostics will be presented.

  15. Relativistic-Klystron two-beam accelerator as a power source for future linear colliders

    SciTech Connect (OSTI)

    Lidia, S.M.; Anderson, D.E.; Eylon, S.; Henestroza, E.; Vanecek, D.L.; Yu, S.S. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Westenskow, G.A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    1999-05-01

    The technical challenge for making two-beam accelerators into realizable power sources for high-energy colliders lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2-kA, 1-MeV, induction gun for a prototype relativistic klystron two-beam accelerator (RK-TBA). The electron source will be a 8.9 cm diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150-ns flat top (1{percent} energy variation), and a normalized edge emittance of less than 300 pi-mm-mr. The prototype accelerator will be used to study, physics, engineering, and costing issues involved in the application of the RK-TBA concept to linear colliders. We have also been studying optimization parameters, such as frequency, for the application of the RK-TBA concept to multi-TeV linear colliders. As an rf power source the RK-TBA scales favorably up to frequencies around 35 GHz. An overview of this work with details of the design and performance of the prototype injector, beam line, and diagnostics will be presented. {copyright} {ital 1999 American Institute of Physics.}

  16. Relativistic-klystron two-beam accelerator as a power source for future linear colliders

    SciTech Connect (OSTI)

    Anderson, D E; Eylon, S; Henestroza, E; Houck, T L; Lidia, M; Vanecek, D L; Westenskow, G A; Yu, S S

    1998-10-05

    The technical challenge for making two-beam accelerators into realizable power sources for high-energy colliders lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2&A, l-MeV, induction gun for a prototype relativistic klystron two-beam accelerator (RK-TBA). The electron source will be a 8.9 cm diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150-ns flat top (1% energy variation), and a normalized edge emittance of less than 300 pi-mm-n-n. The prototype accelerator will be used to study physics, engineering, and costing issues involved in the application of the RK-TBA concept to linear colliders. We have also been studying optimization parameters, such as frequency, for the application of the RK-TBA concept to multi-TeV linear colliders. As an rf power source the RK-TBA scales favorably up to frequencies around 35 GHz. An overview of this work with details of the design and performance of the prototype injector, beam line, and diagnostics will be presented.

  17. An integrated 6 MV linear accelerator model from electron gun to dose in a water tank

    SciTech Connect (OSTI)

    St Aubin, J.; Steciw, S.; Kirkby, C.; Fallone, B. G. [Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta T6G 2G7 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta T6G 2G7 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)

    2010-05-15

    Purpose: The details of a full simulation of an inline side-coupled 6 MV linear accelerator (linac) from the electron gun to the target are presented. Commissioning of the above simulation was performed by using the derived electron phase space at the target as an input into Monte Carlo studies of dose distributions within a water tank and matching the simulation results to measurement data. This work is motivated by linac-MR studies, where a validated full linac simulation is first required in order to perform future studies on linac performance in the presence of an external magnetic field. Methods: An electron gun was initially designed and optimized with a 2D finite difference program using Child's law. The electron gun simulation served as an input to a 6 MV linac waveguide simulation, which consisted of a 3D finite element radio-frequency field solution within the waveguide and electron trajectories determined from particle dynamics modeling. The electron gun design was constrained to match the cathode potential and electron gun current of a Varian 600C, while the linac waveguide was optimized to match the measured target current. Commissioning of the full simulation was performed by matching the simulated Monte Carlo dose distributions in a water tank to measured distributions. Results: The full linac simulation matched all the electrical measurements taken from a Varian 600C and the commissioning process lead to excellent agreements in the dose profile measurements. Greater than 99% of all points met a 1%/1mm acceptance criterion for all field sizes analyzed, with the exception of the largest 40x40 cm{sup 2} field for which 98% of all points met the 1%/1mm acceptance criterion and the depth dose curves matched measurement to within 1% deeper than 1.5 cm depth. The optimized energy and spatial intensity distributions, as given by the commissioning process, were determined to be non-Gaussian in form for the inline side-coupled 6 MV linac simulated. Conclusions: An integrated simulation of an inline side-coupled 6 MV linac has been completed and benchmarked matching all electrical and dosimetric measurements to high accuracy. The results showed non-Gaussian spatial intensity and energy distributions for the linac modeled.

  18. Automatic Beam Path Analysis of Laser Wakefield Particle Acceleration Data

    E-Print Network [OSTI]

    Rubel, Oliver

    2010-01-01

    A. Hakim, R¨ bel et al. Automatic Beam Path Analysis of399, 1976. R¨ bel et al. Automatic Beam Path Analysis ofAutomatic Beam Path Analysis of Laser Wake?eld Particle

  19. Design of a MeV, 4kA linear induction accelerator for flash radiography

    SciTech Connect (OSTI)

    Kulke, B.; Brier, R.; Chapin, W.

    1981-02-10

    For verifying the hydrodynamics of nuclear weapons design it is useful to have flash x-ray machines that can deliver a maximum dose in a minimum pulse length and with very high reliability. At LLNL, such a requirement was identified some years ago as 500 roentgens at one meter, in a 60 nsec pulse length. In response to this requirement, a linear induction accelerator was proposed to and funded by DOE in 1977. The design of this machine, called FXR, has now been completed and construction has begun. The FXR design extends the parameters of a similar machine that had been built and operated at LBL, Berkeley, some ten years ago. Using a cold cathode injector followed by 48 accelerator modules rated at 400 kV each, the FXR machine will accelerate a 4 kA electron beam pulse to 20 MeV final energy. Key design features are the generation and the stable transport of a low emittance (100 mr-cm) beam from a field emitter diode, the design of reliable, compact energy storage components such as Blumleins, feedlines and accelerator modules, and a computer-assisted control system.

  20. Report of the ICFA Beam Dynamics Workshop 'Accelerators for a Higgs Factory: Linear vs. Circular' (HF2012)

    E-Print Network [OSTI]

    Alain Blondel; Alex Chao; Weiren Chou; Jie Gao; Daniel Schulte; Kaoru Yokoya

    2013-02-15

    This paper is a summary report of the ICFA Beam Dynamics Workshop 'Accelerators for a Higgs Factory: Linear vs. Circular' (HF2012). It discusses four types of accelerators as possible candidates for a Higgs factory: linear e+e- colliders, circular e+e- colliders, muon collider and photon colliders. The comparison includes: physics reach, performance (energy and luminosity), upgrade potential, technology maturity and readiness, and technical challenges requiring further R&D.

  1. Parameter choices for a muon recirculating linear accelerator from 5 to 63 GeV

    SciTech Connect (OSTI)

    Berg, J. S.

    2014-06-19

    A recirculating linear accelerator (RLA) has been proposed to accelerate muons from 5 to 63 GeV for a muon collider. It should be usable both for a Higgs factory and as a stage for a higher energy collider. First, the constraints due to the beam loading are computed. Next, an expression for the longitudinal emittance growth to lowest order in the longitudinal emittance is worked out. After finding the longitudinal expression, a simplified model that describes the arcs and their approximate expression for the time of flight dependence on energy in those arcs is found. Finally, these results are used to estimate the parameters required for the RLA arcs and the linac phase.

  2. Upgrade of the MIT Linear Electrostatic Ion Accelerator (LEIA) for nuclear diagnostics development for Omega, Z and the NIF

    E-Print Network [OSTI]

    diagnostics. In addition, in situ measurements of the on-target beam profile, made with a CCD camera, are usedUpgrade of the MIT Linear Electrostatic Ion Accelerator (LEIA) for nuclear diagnostics development accelerators Phys. Plasmas 19, 023107 (2012) Microgan electron cyclotron resonance ion source in a Van de

  3. A Linear Collider Based on Nonlinear Plasma Wake-field Acceleration* J. Rosenzweig, N. Barov, E. Colby

    E-Print Network [OSTI]

    -field accelerator, all driven by a high average current, pulse compressed, rf photoinjector-fed linac. Issues this system is nonlinear from the point of view of the plasma response (all of the plasma electrons are driven394 A Linear Collider Based on Nonlinear Plasma Wake-field Acceleration* J. Rosenzweig, N. Barov, E

  4. Constraints on particle acceleration sites in the Crab Nebula from relativistic MHD simulations

    E-Print Network [OSTI]

    Olmi, Barbara; Amato, Elena; Bucciantini, Niccolò

    2015-01-01

    The Crab Nebula is one of the most efficient accelerators in the Galaxy and the only galactic source showing direct evidence of PeV particles. In spite of this, the physical process behind such effective acceleration is still a deep mystery. While particle acceleration, at least at the highest energies, is commonly thought to occur at the pulsar wind termination shock, the properties of the upstream flow are thought to be non-uniform along the shock surface, and important constraints on the mechanism at work come from exact knowledge of where along this surface particles are being accelerated. Here we use axisymmetric relativistic MHD simulations to obtain constraints on the acceleration site(s) of particles of different energies in the Crab Nebula. Various scenarios are considered for the injection of particles responsible for synchrotron radiation in the different frequency bands, radio, optical and X-rays. The resulting emission properties are compared with available data on the multi wavelength time varia...

  5. Measurements of Neutron Induced Cross Sections at the Oak Ridge Electron Linear Accelerator

    SciTech Connect (OSTI)

    Guber, K.H.; Harvey, J.A.; Hill, N.W.; Koehler, P.E.; Leal, L.C.; Sayer, R.O.; Spencer, R.R.

    1999-09-20

    We have used the Oak Ridge Electron Linear Accelerator (ORELA) to measure neutron total and the fission cross sections of 233U in the energy range from 0.36 eV to ~700 keV. We report average fission and total cross sections. Also, we measured the neutron total cross sections of 27Al and Natural chlorine as well as the capture cross section of Al over an energy range from 100 eV up to about 400 keV.

  6. Interactive visualization of particle beams for accelerator design

    SciTech Connect (OSTI)

    Wilson, Brett; Ma, Kwan-Liu; Qiang, Ji; Ryne, Robert

    2002-01-15

    We describe a hybrid data-representation and rendering technique for visualizing large-scale particle data generated from numerical modeling of beam dynamics. The basis of the technique is mixing volume rendering and point rendering according to particle density distribution, visibility, and the user's instruction. A hierarchical representation of the data is created on a parallel computer, allowing real-time partitioning into high-density areas for volume rendering, and low-density areas for point rendering. This allows the beam to be interactively visualized while preserving the fine structure usually visible only with slow point based rendering techniques.

  7. FOCUSED ACCELERATION OF COSMIC-RAY PARTICLES IN NON-UNIFORM MAGNETIC FIELDS

    SciTech Connect (OSTI)

    Litvinenko, Yuri E. [Department of Mathematics, University of Waikato, P.B. 3105, Hamilton (New Zealand); Schlickeiser, R. [Instituet fuer Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

    2011-05-10

    The Fokker-Planck equation for cosmic-ray particles in a spatially varying guide magnetic field in a turbulent plasma is analyzed. An expression is derived for the mean rate of change of particle momentum, caused by the effect of adiabatic focusing in a non-uniform guide field. Results of an earlier diffusion-limit analysis are confirmed, and the physical picture is clarified by working directly with the Fokker-Planck equation. A distributed first-order Fermi acceleration mechanism is identified, which can be termed focused acceleration. If the forward- and backward-propagating waves have equal polarizations, focused acceleration operates when the net cross helicity of an Alfvenic slab turbulence is either negative in a diverging guide field or positive in a converging guide field. It is suggested that focused acceleration can contribute to the formation of the anomalous cosmic-ray spectrum at the heliospheric termination shock.

  8. The Black Hole Particle Accelerator as a Machine to make Baby Universes

    E-Print Network [OSTI]

    Hamilton, A J S

    2013-01-01

    General relativity predicts that the inner horizon of an astronomically realistic rotating black hole is subject to the mass inflation instability. The inflationary instability acts like a gravity-powered particle accelerator of extraordinary power, accelerating accreted streams of particles along the principal outgoing and ingoing null directions at the inner horizon to collision energies that would, if nothing intervened, typically exceed exponentially the Planck energy. The inflationary instability is fueled by ongoing accretion, and is occurring inevitably in essentially every black hole in our Universe. This extravagant machine, the Black Hole Particle Accelerator, has the hallmarks of a device to make baby universes. Since collisions are most numerous inside supermassive black holes, reproductive efficiency requires our Universe to make supermassive black holes efficiently, as is observed.

  9. The Black Hole Particle Accelerator as a Machine to make Baby Universes

    E-Print Network [OSTI]

    A. J. S. Hamilton

    2013-05-20

    General relativity predicts that the inner horizon of an astronomically realistic rotating black hole is subject to the mass inflation instability. The inflationary instability acts like a gravity-powered particle accelerator of extraordinary power, accelerating accreted streams of particles along the principal outgoing and ingoing null directions at the inner horizon to collision energies that would, if nothing intervened, typically exceed exponentially the Planck energy. The inflationary instability is fueled by ongoing accretion, and is occurring inevitably in essentially every black hole in our Universe. This extravagant machine, the Black Hole Particle Accelerator, has the hallmarks of a device to make baby universes. Since collisions are most numerous inside supermassive black holes, reproductive efficiency requires our Universe to make supermassive black holes efficiently, as is observed.

  10. The acceleration of electrons at perpendicular shocks and its implication for solar energetic particle events

    SciTech Connect (OSTI)

    Guo Fan; Giacalone, Joe

    2012-11-20

    We present a study of the acceleration of electrons at a perpendicular shock that propagates through a turbulent magnetic field. The energization process of electrons is investigated by utilizing a combination of hybrid (kinetic ions and fluid electron) simulations and test-particle electron simulations. In this method, the motions of the test-particle electrons are numerically integrated in the time-dependent electric and magnetic fields generated by two-dimensional hybrid simulations. We show that large-scale magnetic fluctuations effect electrons in a number of ways and lead to efficient and rapid energization at the shock front. Since the electrons mainly follow along magnetic lines of force, the large-scale braiding of field lines in space allows the fast-moving electrons to interact with the shock front and get accelerated multiple times. Ripples in the shock front occurring at various scales will also contribute to the acceleration by mirroring the electrons. Our calculation shows that this process favors electron acceleration at perpendicular shocks. The acceleration efficiency is critically dependent on the turbulence amplitude and coherence length. We also discuss the implication of this study for solar energetic particles (SEPs) by comparing the acceleration of electrons with that of protons. Their correlation indicates that perpendicular shocks play an important role in SEP events.

  11. MONTE CARLO SIMULATIONS OF NONLINEAR PARTICLE ACCELERATION IN PARALLEL TRANS-RELATIVISTIC SHOCKS

    SciTech Connect (OSTI)

    Ellison, Donald C.; Warren, Donald C. [Physics Department, North Carolina State University, Box 8202, Raleigh, NC 27695 (United States); Bykov, Andrei M., E-mail: don_ellison@ncsu.edu, E-mail: ambykov@yahoo.com [Ioffe Institute for Physics and Technology, 194021 St. Petersburg (Russian Federation)

    2013-10-10

    We present results from a Monte Carlo simulation of a parallel collisionless shock undergoing particle acceleration. Our simulation, which contains parameterized scattering and a particular thermal leakage injection model, calculates the feedback between accelerated particles ahead of the shock, which influence the shock precursor and 'smooth' the shock, and thermal particle injection. We show that there is a transition between nonrelativistic shocks, where the acceleration efficiency can be extremely high and the nonlinear compression ratio can be substantially greater than the Rankine-Hugoniot value, and fully relativistic shocks, where diffusive shock acceleration is less efficient and the compression ratio remains at the Rankine-Hugoniot value. This transition occurs in the trans-relativistic regime and, for the particular parameters we use, occurs around a shock Lorentz factor ?{sub 0} = 1.5. We also find that nonlinear shock smoothing dramatically reduces the acceleration efficiency presumed to occur with large-angle scattering in ultra-relativistic shocks. Our ability to seamlessly treat the transition from ultra-relativistic to trans-relativistic to nonrelativistic shocks may be important for evolving relativistic systems, such as gamma-ray bursts and Type Ibc supernovae. We expect a substantial evolution of shock accelerated spectra during this transition from soft early on to much harder when the blast-wave shock becomes nonrelativistic.

  12. Test particle simulation of direct laser acceleration in a density-modulated plasma waveguide

    SciTech Connect (OSTI)

    Lin, M.-W.; Jovanovic, I.

    2012-11-15

    Direct laser acceleration (DLA) of electrons by the use of the intense axial electric field of an ultrafast radially polarized laser pulse is a promising technique for future compact accelerators. Density-modulated plasma waveguides can be implemented for guiding the propagation of the laser pulse to extend the acceleration distance and for the quasi-phase-matching between the accelerated electrons and the laser pulse. A test particle model is developed to study the optimal axial density modulation structure of plasma waveguides for laser pulses to efficiently accelerate co-propagating electrons. A simple analytical approach is also presented, which can be used to estimate the energy gain in DLA. The analytical model is validated by the test particle simulation. The effect of injection phase and acceleration of electrons injected at various radial positions are studied. The results indicate that a positively chirped density modulation of the waveguide structure is required to accelerate electron with low initial energies, and can be effectively optimized. A wider tolerance on the injection phase and radial distance from the waveguide axis exists for electrons injected with a higher initial energy.

  13. Non-linear electrophoresis of ideally polarizable particles

    E-Print Network [OSTI]

    Chan, Wai Hong Ronald

    2014-01-01

    This thesis investigates the non-linear regime of electrophoresis, in particular the variation of electrophoretic velocity with electric field at high field strengths. Known theoretical approaches to the problem accounting ...

  14. Preliminary Safety Analysis Report (PSAR), The NSLS 200 MeV Linear Electron Accelerator

    SciTech Connect (OSTI)

    Blumberg, L.N.; Ackerman, A.I.; Dickinson, T.; Heese, R.N.; Larson, R.A.; Neuls, C.W.; Pjerov, S.; Sheehan, J.F.

    1993-06-15

    The radiological, fire and electrical hazards posed by a 200 MeV electron Linear Accelerator, which the NSLS Department will install and commission within a newly assembled structure, are addressed in this Preliminary Safety Analysis Report. Although it is clear that this accelerator is intended to be the injector for a future experimental facility, we address only the Linac in the present PSAR since neither the final design nor the operating characteristics of the experimental facility are known at the present time. The fire detection and control system to be installed in the building is judged to be completely adequate in terms of the marginal hazard presented - no combustible materials other than the usual cabling associated with such a facility have been identified. Likewise, electrical hazards associated with power supplies for the beam transport magnets and accelerator components such as the accelerator klystrons and electron gun are classified as marginal in terms of potential personnel injury, cost of equipment lost, program downtime and public impact perceptions as defined in the BNL Environmental Safety and Health Manual and the probability of occurrence is deemed to be remote. No unusual features have been identified for the power supplies or electrical distribution system, and normal and customary electrical safety standards as practiced throughout the NSLS complex and the Laboratory are specified in this report. The radiation safety hazards are similarly judged to be marginal in terms of probability of occurrence and potential injury consequences since, for the low intensity operation proposed - a factor of 25 less than the maximum Linac capability specified by the vendor - the average beam power is only 0.4 watts. The shielding specifications given in this report will give adequate protection to both the general public and nonradiation workers in areas adjacent to the building as well as radiation workers within the controlled access building.

  15. A STEADY-STATE FEL: PARTICLE DYNAMICS IN THE FEL PORTION OF A TWO-BEAM ACCELERATOR

    E-Print Network [OSTI]

    Sternbach, E.

    2008-01-01

    September 8-13, 1985 A STEADY-STATE FEL: PARTICLE DYNAMICSIN THE FEL PORTION OF A TWO-BEAM ACCELERATOR E. SternbachLBL-19939 A STEADY-STATE FEL: PARTICLE DYNAMICS IN THE FEL

  16. Experimental measurement methods and data on irradiation of functional design materials by helium ions in linear accelerator

    E-Print Network [OSTI]

    R. A. Anokhin; V. N. Voyevodin; S. N. Dubnyuk; A. M. Egorov; B. V. Zaitsev; A. F. Kobets; O. P. Ledenyov; K. V. Pavliy; V. V. Ruzhitsky; G. D. Tolstolutskaya

    2013-09-03

    The experimental research on the irradiation of the functional design materials by the Helium ions in the linear accelerator is conducted. The experimental measurements techniques and data on the irradiation of the functional design materials by the Helium ions with the energy up to 4 MeV, including the detailed scheme of experimental measurements setup, are presented. The new design of accelerating structure of the IH-type such as POS-4, using the method of alternate-phase focusing with the step-by-step change of the synchronous phase along the focusing periods in a linear accelerator, is developed with the aim to irradiate the functional design materials by the Helium ions. The new design of the injector of the charged Helium ions with the energy of 120 KeV at the output of an accelerating tube and the accelerating structure of the type of POS-4 for the one time charged Helium ions acceleration in the linear accelerator are researched and developed. The special chamber for the irradiation of functional design materials by the Helium ions is also created. In the process of experiment, the temperature of a sample, the magnitude of current of Helium ions beam and the irradiation dose of sample are measured precisely. The experimental measurement setup and techniques are fully tested and optimized in the course of the research on the electro-physical properties of irradiated samples and the thermal-desorption of Helium ions in a wide range of temperatures

  17. Proceedings of the 2003 Particle Accelerator Conference CONCEPTDESIGN OF THE TARGETEIOFZN SYSTEM FOR THE BNL

    E-Print Network [OSTI]

    McDonald, Kirk

    Proceedings of the 2003 Particle Accelerator Conference CONCEPTDESIGN OF THE TARGETEIOFZN SYSTEM of 20ps duration will flow through the horn at 2.5 Hz repetition rate inducing high compressive forces are the low resistivity, the high strength and the resistance to corrosion and micro-cracking. The pulsed

  18. Developments in accelerators and instrumentation relevant to imaging with charged particles and positron emitters

    SciTech Connect (OSTI)

    Alonso, J.R.

    1980-11-01

    In past years particle accelerators have become increasingly important tools for the advancement of medical science. From the pace of advancing technology and current directions in medical research, it is clear that this relationship between accelerators and medicine will only grow stronger in future years. In view of this importance, this relationship is investigated in some detail, with an eye not so much towards the medical uses of the beams produced, but more towards the technology associated with these accelerators and the criteria which make for successful incorporation of these machines into the clinical environment. In order to lay the necessary groundwork, the different kinds of accelerators found in medical use today are reviewed briefly discussing salient points of each.

  19. Neutron source, linear-accelerator fuel enricher and regenerator and associated methods

    DOE Patents [OSTI]

    Steinberg, Meyer (Huntington Station, NY); Powell, James R. (Shoreham, NY); Takahashi, Hiroshi (Setauket, NY); Grand, Pierre (Blue Point, NY); Kouts, Herbert (Brookhaven, NY)

    1982-01-01

    A device for producing fissile material inside of fabricated nuclear elements so that they can be used to produce power in nuclear power reactors. Fuel elements, for example, of a LWR are placed in pressure tubes in a vessel surrounding a liquid lead-bismuth flowing columnar target. A linear-accelerator proton beam enters the side of the vessel and impinges on the dispersed liquid lead-bismuth columns and produces neutrons which radiate through the surrounding pressure tube assembly or blanket containing the nuclear fuel elements. These neutrons are absorbed by the natural fertile uranium-238 elements and are transformed to fissile plutonium-239. The fertile fuel is thus enriched in fissile material to a concentration whereby they can be used in power reactors. After use in the power reactors, dispensed depleted fuel elements can be reinserted into the pressure tubes surrounding the target and the nuclear fuel regenerated for further burning in the power reactor.

  20. Particle Acceleration in Solar Flares and Enrichment of 3He and Heavy Ions

    E-Print Network [OSTI]

    Vahe' Petrosian

    2008-08-13

    We discuss possible mechanisms of acceleration of particles in solar flares and show that turbulence plays an important role in all the mechanism. It is also argued that stochastic particle acceleration by turbulent plasma waves is the most likely mechanism for production of the high energy electrons and ions responsible for observed radiative signatures of solar flares and for solar energetic particle or SEPs, and that the predictions of this model agrees well with many past and recent high spectral and temporal observations of solar flares. It is shown that, in addition, the model explains many features of SEPs that accompany flares. In particular we show that it can successfully explain the observed extreme enhancement, relative to photospheric values, of $^3$He ions and the relative spectra of $^3$He and $^4$He. It has also the potential of explaining the relative abundances of most ions including the increasing enhancements of heavy ions with ion mass or mass-to-charge ratio.

  1. Compact accelerator for medical therapy

    DOE Patents [OSTI]

    Caporaso, George J.; Chen, Yu-Jiuan; Hawkins, Steven A.; Sampayan, Stephen E.; Paul, Arthur C.

    2010-05-04

    A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (.about.70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.

  2. Electron beam dynamics in the long-pulse, high-current DARHT-II linear induction accelerator

    SciTech Connect (OSTI)

    Ekdahl, Carl A; Abeyta, Epifanio O; Aragon, Paul; Archuleta, Rita; Cook, Gerald; Dalmas, Dale; Esquibel, Kevin; Gallegos, Robert A; Garnett, Robert; Harrison, James F; Johnson, Jeffrey B; Jacquez, Edward B; Mccuistian, Brian T; Montoya, Nicholas A; Nath, Subrato; Nielsen, Kurt; Oro, David; Prichard, Benjamin; Rowton, Lawrence; Sanchez, Manolito; Scarpetti, Raymond; Schauer, Martin M; Seitz, Gerald; Schulze, Martin; Bender, Howard A; Broste, William B; Carlson, Carl A; Frayer, Daniel K; Johnson, Douglas E; Tom, C Y; Williams, John; Hughes, Thomas; Anaya, Richard; Caporaso, George; Chambers, Frank; Chen, Yu - Jiuan; Falabella, Steve; Guethlein, Gary; Raymond, Brett; Richardson, Roger; Trainham, C; Weir, John; Genoni, Thomas; Toma, Carsten

    2009-01-01

    The DARHT-II linear induction accelerator (LIA) now accelerates 2-kA electron beams to more than 17 MeV. This LIA is unique in that the accelerated current pulse width is greater than 2 microseconds. This pulse has a flat-top region where the final electron kinetic energy varies by less than 1% for more than 1.5 microseconds. The long risetime of the 6-cell injector current pulse is 0.5 {micro}s, which can be scraped off in a beam-head cleanup zone before entering the 68-cell main accelerator. We discuss our experience with tuning this novel accelerator; and present data for the resulting beam transport and dynamics. We also present beam stability data, and relate these to previous stability experiments at lower current and energy.

  3. COMBINING PARTICLE ACCELERATION AND CORONAL HEATING VIA DATA-CONSTRAINED CALCULATIONS OF NANOFLARES IN CORONAL LOOPS

    SciTech Connect (OSTI)

    Gontikakis, C.; Efthymiopoulos, C.; Georgoulis, M. K.; Patsourakos, S.; Anastasiadis, A.

    2013-07-10

    We model nanoflare heating of extrapolated active-region coronal loops via the acceleration of electrons and protons in Harris-type current sheets. The kinetic energy of the accelerated particles is estimated using semi-analytical and test-particle-tracing approaches. Vector magnetograms and photospheric Doppler velocity maps of NOAA active region 09114, recorded by the Imaging Vector Magnetograph, were used for this analysis. A current-free field extrapolation of the active-region corona was first constructed. The corresponding Poynting fluxes at the footpoints of 5000 extrapolated coronal loops were then calculated. Assuming that reconnecting current sheets develop along these loops, we utilized previous results to estimate the kinetic energy gain of the accelerated particles. We related this energy to nanoflare heating and macroscopic loop characteristics. Kinetic energies of 0.1-8 keV (for electrons) and 0.3-470 keV (for protons) were found to cause heating rates ranging from 10{sup -6} to 1 erg s{sup -1} cm{sup -3}. Hydrodynamic simulations show that such heating rates can sustain plasma in coronal conditions inside the loops and generate plasma thermal distributions that are consistent with active-region observations. We concluded the analysis by computing the form of X-ray spectra generated by the accelerated electrons using the thick-target approach. These spectra were found to be in agreement with observed X-ray spectra, thus supporting the plausibility of our nanoflare-heating scenario.

  4. X-Band klystron development at the Stanford Linear Accelerator Center

    SciTech Connect (OSTI)

    Sprehn, D.W.

    2000-03-24

    X-band klystrons capable of 75 MW and utilizing either solenoidal or Periodic Permanent Magnet (PPM) focusing are undergoing design, fabrication and testing at the Stanford Linear Accelerator Center (SLAC). The klystron development is part of an effort to realize components necessary for the construction of the Next Linear Collider (NLC). SLAC has completed a solenoidal-focused X-band klystron development effort to study the design and operation of tubes with beam microperveances of 1.2. As of early 2000, nine 1.2{micro}K klystrons have been tested to 50 MW at 1.5{micro}s. The first 50 MW PPM klystron, constructed in 1996, was designed with a 0.6 {micro}K beam at 465 kV and uses a 5-cell traveling-wave output structure. Recent testing of this tube at wider pulsewidths has reached 50 MW at 55% efficiency, 2.4{micro}s and 60 Hz. A 75 MW PPM klystron prototype was constructed in 1998 and has reached the NLC design target of 75 MW at 1.5 {micro}s. A new 75 MW PPM klystron design, which is aimed at reducing the cost and increasing the reliability of multi-megawatt PPM klystrons, is under investigation. The tube is scheduled for testing during early 2001.

  5. Final Environmental Assessment for the construction and operation of an office building at the Stanford Linear Accelerator Center. Part 2

    SciTech Connect (OSTI)

    1995-08-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-1107, analyzing the environmental effects relating to the construction and operation of an office building at the Stanford Linear Accelerator Center (SLAC). SLAC is a national facility operated by Stanford University, California, under contract with DOE. The center is dedicated to research in elementary particle physics and in those fields that make use of its synchrotron facilities. The objective for the construction and operation of an office building is to provide adequate office space for existing SLAC Waste Management (WM) personnel, so as to centralize WM personnel and to make WM operations more efficient and effective. Based on the analyses in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required. This report contains the Environmental Assessment, as well as the Finding of No Significant Impact (FONSI).

  6. Proposal for the Award of a Contract for the Civil Engineering work for the Building designed to House the LEP Pre-injector Linear Accelerator

    E-Print Network [OSTI]

    1982-01-01

    Proposal for the Award of a Contract for the Civil Engineering work for the Building designed to House the LEP Pre-injector Linear Accelerator

  7. The PSI DSP Carrier (PDC) Board - a Digital Back-end for Bunch-to-bunch and Global Orbit Feedbacks in Linear Accelerators and Storage Rings

    E-Print Network [OSTI]

    Keil, B; Marinkovic, G; Pollet, P; Roggli, M

    2008-01-01

    The PSI DSP Carrier (PDC) Board - a Digital Back-end for Bunch-to-bunch and Global Orbit Feedbacks in Linear Accelerators and Storage Rings

  8. Is it possible to discover a dark matter particle with an accelerator?

    E-Print Network [OSTI]

    Vadim A. Bednyakov

    2015-06-28

    The paper contains description of the main properties of the galactic dark matter (DM) particles, available approaches for detection of DM, main features of direct DM detection, ways to estimate prospects for the DM detection, the first collider search for a DM candidate within an Effective Field Theory, complete review of ATLAS results of the DM candidate search with LHC RUN I, and less complete review of "exotic" dark particle searches with other accelerators and not only. From these considerations it follows that one is unable to prove, especially model-independently,a discovery of a DM particle with an accelerator, or collider. One can only obtain evidence on existence of a weakly interacting neutral particle, which could be, or could not be the DM candidate. The current LHC DM search program uses only the missing transverse energy signature. Non-observation of any excess above Standard Model expectations forces the LHC experiments to enter into the same fighting for the best exclusion curve, in which (almost) all direct and indirect DM search experiments permanently take place. But this fighting has very little (almost nothing) to do with a real possibility of discovering a DM particle. The true DM particles possess an exclusive galactic signature --- annual modulation of a signal, which is accessible today only for direct DM detection experiments. There is no way for it with a collider, or accelerator. Therefore to prove the DM nature of a collider-discovered candidate one must find the candidate in a direct DM experiment and demonstrate the galactic signature for the candidate. Furthermore, being observed, the DM particle must be implemented into a modern theoretical framework. The best candidate is the supersymmetry, which looks today inevitable for coherent interpretation of all available DM data.

  9. Acceleration of particles and shells by Reissner-Nordström naked singularities

    E-Print Network [OSTI]

    Mandar Patil; Pankaj S. Joshi; Masashi Kimura; Ken-ichi Nakao

    2012-09-20

    We explore the Reissner-Nordstr\\"{o}m naked singularities with a charge $Q$ larger than its mass $M$ from the perspective of the particle acceleration. We first consider a collision between two test particles following the radial geodesics in the Reissner-Nordstr\\"{o}m naked singular geometry. An initially radially ingoing particle turns back due to the repulsive effect of gravity in the vicinity of naked singularity. Such a particle then collides with an another radially ingoing particle. We show that the center of mass energy of collision taking place at $r \\approx M$ is unbound, in the limit where the charge transcends the mass by arbitrarily small amount $0naked singularity is around million years while it is many orders of magnitude larger than Hubble time in the black hole case. We then study the collision of the neutral spherically symmetric shells made up of dust particles. In this case, it is possible to treat the situation by exactly taking into account the gravity due to the shells using Israel`s thin shell formalism, and thus this treatment allows us to go beyond the test particle approximation. The center of mass energy of collision of the shells is then calculated in a situation analogous to the test particle case and is shown to be bounded above. However, we find thatthe energy of a collision between two of constituent particles of the shells at the center of mass frame can exceed the Planck energy.

  10. Status of materials handbooks for particle accelerator and nuclear reactor applications

    SciTech Connect (OSTI)

    Maloy, Stuart [Los Alamos National Laboratory (LANL); Rogers, Berylene [Los Alamos National Laboratory (LANL); Ren, Weiju [ORNL; Philip, Rittenhouse [Consultant

    2008-01-01

    In support of research and development for accelerator applications, a materials handbook was developed in August of 1998 funded by the Accelerator Production of Tritium Project. This handbook, presently called Advanced Fuel Cycle Initiative (AFCI) Materials Handbook, Materials Data for Particle Accelerator Applications, has just issued Revision 5 and contains detailed information showing the effects of irradiation on many properties for a wide variety of materials. Development of a web-accessible materials database for Generation IV Reactor Programs has been ongoing for about three years. This handbook provides a single authoritative source for qualified materials data applicable to all Generation IV reactor concepts. A beta version of this Gen IV Materials Handbook has been completed and is presently under evaluation.

  11. PHYSICAL REVIEW SPECIAL TOPICS -ACCELERATORS AND BEAMS, VOLUME 5, 011001 (2002) Energy doubler for a linear collider

    E-Print Network [OSTI]

    2002-01-01

    . Wang University of California, Los Angeles, Los Angeles, California 90095 R. Assmann, F. J. Decker, M sections several meters in length to double the energy of a linear collider just before the collision point of microbunches with the first driving a plasma wake that accelerates the second. The luminosity of the doubled

  12. Generation and Characterization of Electron Bunches with Ramped Current Profiles in a Dual-Frequency Superconducting Linear Accelerator

    E-Print Network [OSTI]

    Piot, P; Gerth, C; Dohlus, M; Lemery, F; Mihalcea, D; Stoltz, P; Vogt, M

    2011-01-01

    We report on the successful experimental generation of electron bunches with ramped current profiles. The technique relies on impressing nonlinear correlations in the longitudinal phase space using a superconducing radiofrequency linear accelerator operating at two frequencies and a current-enhancing dispersive section. The produced $\\sim 700$-MeV bunches have peak currents of the order of a kilo-Amp\\`ere. Data taken for various accelerator settings demonstrate the versatility of the method and in particular its ability to produce current profiles that have a quasi-linear dependency on the longitudinal (temporal) coordinate. The measured bunch parameters are shown, via numerical simulations, to produce gigavolt-per-meter peak accelerating electric fields with transformer ratios larger than 2 in dielectric-lined waveguides.

  13. Generation and Characterization of Electron Bunches with Ramped Current Profiles in a Dual-Frequency Superconducting Linear Accelerator

    SciTech Connect (OSTI)

    Piot, P [Northern Illinois U.; Fermilab; Behrens, C; Gerth, C; Dohlus, M [DESY; Lemery, F; Mihalcea, D [Northern Illinois U.; Stoltz, P [Tech-X, Boulder; Vogt, M [DESY

    2011-09-07

    We report on the successful experimental generation of electron bunches with ramped current profiles. The technique relies on impressing nonlinear correlations in the longitudinal phase space using a superconducing radiofrequency linear accelerator operating at two frequencies and a current-enhancing dispersive section. The produced {approx} 700-MeV bunches have peak currents of the order of a kilo-Ampere. Data taken for various accelerator settings demonstrate the versatility of the method and in particular its ability to produce current profiles that have a quasi-linear dependency on the longitudinal (temporal) coordinate. The measured bunch parameters are shown, via numerical simulations, to produce gigavolt-per-meter peak accelerating electric fields with transformer ratios larger than 2 in dielectric-lined waveguides.

  14. The design of a simulated in-line side-coupled 6 MV linear accelerator waveguide

    SciTech Connect (OSTI)

    St Aubin, Joel; Steciw, Stephen; Fallone, B. G. [Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta T6G 2G7 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada) and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta T6G 2G7 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); and Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)

    2010-02-15

    Purpose: The design of a 3D in-line side-coupled 6 MV linac waveguide for medical use is given, and the effect of the side-coupling and port irises on the radio frequency (RF), beam dynamics, and dosimetric solutions is examined. This work was motivated by our research on a linac-MR hybrid system, where accurate electron trajectory information for a clinical medical waveguide in the presence of an external magnetic field was needed. Methods: For this work, the design of the linac waveguide was generated using the finite element method. The design outlined here incorporates the necessary geometric changes needed to incorporate a full-end accelerating cavity with a single-coupling iris, a waveguide-cavity coupling port iris that allows power transfer into the waveguide from the magnetron, as well as a method to control the RF field magnitude within the first half accelerating cavity into which the electrons from the gun are injected. Results: With the full waveguide designed to resonate at 2998.5{+-}0.1 MHz, a full 3D RF field solution was obtained. The accuracy of the 3D RF field solution was estimated through a comparison of important linac parameters (Q factor, shunt impedance, transit time factor, and resonant frequency) calculated for one accelerating cavity with the benchmarked program SUPERFISH. It was found that the maximum difference between the 3D solution and SUPERFISH was less than 0.03%. The eigenvalue solver, which determines the resonant frequencies of the 3D side-coupled waveguide simulation, was shown to be highly accurate through a comparison with lumped circuit theory. Two different waveguide geometries were examined, one incorporating a 0.5 mm first side cavity shift and another with a 1.5 mm first side cavity shift. The asymmetrically placed side-coupling irises and the port iris for both models were shown to introduce asymmetries in the RF field large enough to cause a peak shift and skewing (center of gravity minus peak shift) of an initially cylindrically uniform electron beam accelerating within the waveguide. The shifting and skewing of the electron beam were found to be greatest due to the effects of the side-coupling irises on the RF field. A further Monte Carlo study showed that this effect translated into a 1% asymmetry in a 40x40 cm{sup 2} field dose profile. Conclusions: A full 3D design for an in-line side-coupled 6 MV linear accelerator that emulates a common commercial waveguide has been given. The effect of the side coupling on the dose distribution has been shown to create a slight asymmetry, but overall does not affect the clinical applicability of the linac. The 3D in-line side-coupled linac model further provides a tool for the investigation of linac performance within an external magnetic field, which exists in an integrated linac-MR system.

  15. Gamma-ray novae as probes of relativistic particle acceleration at non-relativistic shocks

    E-Print Network [OSTI]

    Metzger, Brian D; Vurm, Indrek; Hascoet, Romain; Beloborodov, Andrei M; Chomiuk, Laura

    2015-01-01

    The Fermi LAT discovery that classical novae produce >100 MeV gamma-rays establishes that shocks and relativistic particle acceleration are key features of these events. These shocks are likely to be radiative due to the high densities of the nova ejecta at early times coincident with the gamma-ray emission. Thermal X-rays radiated behind the shock are absorbed by neutral gas and reprocessed into optical emission, similar to Type IIn (interacting) supernovae. The ratio of gamma-ray and optical luminosities, L_gam/L_opt, thus sets a lower limit on the fraction of the shock power used to accelerate relativistic particles, e_nth. The measured values of L_gam/L_opt for two classical novae, V1324 Sco and V339 Del, constrains e_nth > 1e-2 and > 1e-3, respectively. Inverse Compton models for the gamma-ray emission are disfavored given the low electron acceleration efficiency, e_nth ~ 1e-4-1e-3, inferred from observations of Galactic cosmic rays and particle-in-cell (PIC) numerical simulations. Recent hybrid PIC simu...

  16. Settlement in an Amereican landscape : a place of work amidst a particle accelerator's transformation of the Texas prarie

    E-Print Network [OSTI]

    Falliers, Christopher B. (Christopher Basil)

    1991-01-01

    This thesis considers the design of the research facility accompanying the Superconducting Super Collider, a large particle accelerator planned for central Texas. It will focus on this Pl'Qject as a form of human settlement ...

  17. Optical transition radiation used in the diagnostic of low energy and low current electron beams in particle accelerators

    SciTech Connect (OSTI)

    Silva, T. F.; Bonini, A. L.; Lima, R. R.; Maidana, N. L.; Malafronte, A. A.; Pascholati, P. R.; Vanin, V. R.; Martins, M. N. [Institute of Physics, University of Sao Paulo, CP 66318, 05315-970 Sao Paulo, SP (Brazil)

    2012-09-15

    Optical transition radiation (OTR) plays an important role in beam diagnostics for high energy particle accelerators. Its linear intensity with beam current is a great advantage as compared to fluorescent screens, which are subject to saturation. Moreover, the measurement of the angular distribution of the emitted radiation enables the determination of many beam parameters in a single observation point. However, few works deals with the application of OTR to monitor low energy beams. In this work we describe the design of an OTR based beam monitor used to measure the transverse beam charge distribution of the 1.9-MeV electron beam of the linac injector of the IFUSP microtron using a standard vision machine camera. The average beam current in pulsed operation mode is of the order of tens of nano-Amps. Low energy and low beam current make OTR observation difficult. To improve sensitivity, the beam incidence angle on the target was chosen to maximize the photon flux in the camera field-of-view. Measurements that assess OTR observation (linearity with beam current, polarization, and spectrum shape) are presented, as well as a typical 1.9-MeV electron beam charge distribution obtained from OTR. Some aspects of emittance measurement using this device are also discussed.

  18. THE INFLUENCE OF THE MASS RATIO ON THE ACCELERATION OF PARTICLES BY FILAMENTATION INSTABILITIES

    SciTech Connect (OSTI)

    Burkart, Thomas; Elbracht, Oliver; Ganse, Urs; Spanier, Felix, E-mail: fspanier@astro.uni-wuerzburg.d [Lehrstuhl fuer Astronomie, Universitaet Wuerzburg, Am Hubland, D-97074 Wuerzburg (Germany)

    2010-09-10

    Almost all sources of high-energy particles and photons are associated with jet phenomena. Prominent sources of such highly relativistic outflows are pulsar winds, active galactic nuclei (AGNs), and gamma-ray bursts. The current understanding of these jets assumes diluted plasmas which are best described as kinetic phenomena. In this kinetic description, particle acceleration to ultrarelativistic speeds can occur in completely unmagnetized and neutral plasmas through insetting effects of instabilities. Even though the morphology and nature of particle spectra are understood to a certain extent, the composition of the jets is not known yet. While Poynting-flux-dominated jets (e.g., occurring in pulsar winds) are certainly composed of electron-positron plasmas, the understanding of the governing physics in AGN jets is mostly unclear. In this paper, we investigate how the constituting elements of an electron-positron-proton plasma behave differently under the variation of the fundamental mass ratio m{sub p} /m{sub e}. We initially studied unmagnetized counterstreaming plasmas using fully relativistic three-dimensional particle-in-cell simulations to investigate the influence of the mass ratio on particle acceleration and magnetic field generation in electron-positron-proton plasmas. We covered a range of mass ratios m{sub p}/m{sub e} between 1 and 100 with a particle number composition of n{sub p}{sup +}/ n{sub e}{sup +} of 1 in one stream, therefore called the pair-proton stream. Protons are injected in the other one, therefore from now on called the proton stream, whereas electrons are present in both to guarantee charge neutrality in the simulation box. We find that with increasing proton mass the instability takes longer to develop and for mass ratios >20 the particles seem to be accelerated in two phases which can be accounted for by the individual instabilities of the different species. This means that for high mass ratios the coupling between electrons/positrons and the heavier protons, which occurs in low mass ratios, disappears.

  19. Linear_Accelerator_C+6_Ions_as_Injector_for_a_Synchrotron, Intended for Hadrons Therapy

    E-Print Network [OSTI]

    Dolya, S N

    2013-01-01

    We consider acceleration light ions by the field of a traveling-wave in a helical waveguide. The frequency of the accelerating RF field f = 100 MHz, generator power P = 2 MW. Ion focusing is provided by a solenoidal magnetic field with the intensity B = 3.5 Tesla. With increasing the accelerator length up to L = 15 m, the final energy of the ions can be increased up to a value of E = 7 MeV / nucleon.

  20. Time-Dependent Stochastic Particle Acceleration in Astrophysical Plasmas: Exact Solutions Including Momentum-Dependent Escape

    E-Print Network [OSTI]

    P. A. Becker; T. Le; C. D. Dermer

    2006-04-24

    Stochastic acceleration of charged particles due to interactions with magnetohydrodynamic (MHD) plasma waves is the dominant process leading to the formation of the high-energy electron and ion distributions in a variety of astrophysical systems. Collisions with the waves influence both the energization and the spatial transport of the particles, and therefore it is important to treat these two aspects of the problem in a self-consistent manner. We solve the representative Fokker-Planck equation to obtain a new, closed-form solution for the time-dependent Green's function describing the acceleration and escape of relativistic ions interacting with Alfven or fast-mode waves characterized by momentum diffusion coefficient $D(p)\\propto p^q$ and mean particle escape timescale $t_esc(p) \\propto p^{q-2}$, where $p$ is the particle momentum and $q$ is the power-law index of the MHD wave spectrum. In particular, we obtain solutions for the momentum distribution of the ions in the plasma and also for the momentum distribution of the escaping particles, which may form an energetic outflow. The general features of the solutions are illustrated via examples based on either a Kolmogorov or Kraichnan wave spectrum. The new expressions complement the results obtained by Park and Petrosian, who presented exact solutions for the hard-sphere scattering case ($q=2$) in addition to other scenarios in which the escape timescale has a power-law dependence on the momentum. Our results have direct relevance for models of high-energy radiation and cosmic-ray production in astrophysical environments such as $\\gamma$-ray bursts, active galaxies, and magnetized coronae around black holes.

  1. Generation and Characterization of Electron Bunches with Ramped Current Profiles in a Dual-Frequency Superconducting Linear Accelerator

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

    Piot, P; Fermilab; Behrens, C; Gerth, C; Dohlus, M; Lemery, F; Mihalcea, D; Stoltz, P; Vogt, M

    2011-09-07

    We report on the successful experimental generation of electron bunches with ramped current profiles. The technique relies on impressing nonlinear correlations in the longitudinal phase space using a superconducing radiofrequency linear accelerator operating at two frequencies and a current-enhancing dispersive section. The produced {approx} 700-MeV bunches have peak currents of the order of a kilo-Ampere. Data taken for various accelerator settings demonstrate the versatility of the method and in particular its ability to produce current profiles that have a quasi-linear dependency on the longitudinal (temporal) coordinate. The measured bunch parameters are shown, via numerical simulations, to produce gigavolt-per-meter peak acceleratingmore »electric fields with transformer ratios larger than 2 in dielectric-lined waveguides.« less

  2. Device on basis of a bent crystal with variable curvature for particle beams steering in accelerators

    E-Print Network [OSTI]

    Afonin, A G; Bulgakov, M K; Chesnokov, Yu A; Chirkov, P N; Lobanova, E V; Lobanov, I S; Lunkov, A N; Maisheev, V A; Poluektov, I V; Sandomirskiy, Yu E; Yazynin, I A

    2012-01-01

    Recently it was proposed to apply a bent single crystal with decreasing curvature instead of uniform bending for improvement of extraction and collimation of a circulating beam in particle accelerators. In the given paper created crystal devices with a variable curvature, realizing this idea are described. Results of measurement of curvature along a crystal plate are informed. It is shown, that with the help of the developed devices it is possible to carry out also high energy beam focusing. The mathematical description of this process is proposed.

  3. Particle sizing by dynamic light scattering: non-linear cumulant analysis

    E-Print Network [OSTI]

    Alastair G. Mailer; Paul S. Clegg; Peter N. Pusey

    2015-04-24

    We revisit the method of cumulants for analysing dynamic light scattering data in particle sizing applications. Here the data, in the form of the time correlation function of scattered light, is written as a series involving the first few cumulants (or moments) of the distribution of particle diffusion constants. Frisken (2001 Applied Optics 40, 4087) has pointed out that, despite greater computational complexity, a non-linear, iterative, analysis of the data has advantages over the linear least-squares analysis used originally. In order to explore further the potential and limitations of cumulant methods we analyse, by both linear and non-linear methods, computer-generated data with realistic `noise', where the parameters of the distribution can be set explicitly. We find that, with modern computers, non-linear analysis is straightforward and robust. The mean and variance of the distribution of diffusion constants can be obtained quite accurately for distributions of width (standard deviation/mean) up to about 0.6, but there appears to be little prospect of obtaining meaningful higher moments.

  4. Advanced laser particle accelerator development at LANL: from fast ignition to radiation oncology

    SciTech Connect (OSTI)

    Flippo, Kirk A [Los Alamos National Laboratory; Gaillard, Sandrine A [Los Alamos National Laboratory; Offermann, D T [Los Alamos National Laboratory; Cobble, J A [Los Alamos National Laboratory; Schmitt, M J [Los Alamos National Laboratory; Gautier, D C [Los Alamos National Laboratory; Kwan, T J T [Los Alamos National Laboratory; Montgomery, D S [Los Alamos National Laboratory; Kluge, Thomas [FZD-GERMANY; Bussmann, Micheal [FZD-GERMANY; Bartal, T [UCSD; Beg, F N [UCSD; Gall, B [UNIV OF MISSOURI; Geissel, M [SNL; Korgan, G [NANOLABZ; Kovaleski, S [UNIV OF MISSOURI; Lockard, T [UNIV OF NEVADA; Malekos, S [NANOLABZ; Schollmeier, M [SNL; Sentoku, Y [UNIV OF NEVADA; Cowan, T E [FZD-GERMANY

    2010-01-01

    Laser-plasma accelerated ion and electron beam sources are an emerging field with vast prospects, and promise many superior applications in a variety of fields such as hadron cancer therapy, compact radioisotope generation, table-top nuclear physics, laboratory astrophysics, nuclear forensics, waste transmutation, SN M detection, and inertial fusion energy. LANL is engaged in several projects seeking to develop compact high current and high energy ion and electron sources. We are especially interested in two specific applications: ion fast ignition/capsule perturbation and radiation oncology in conjunction with our partners at the ForschungsZentrum Dresden-Rossendorf (FZD). Laser-to-beam conversion efficiencies of over 10% are needed for practical applications, and we have already shown inherent etliciencies of >5% from flat foils, on Trident using only a 5th of the intensity and energy of the Nova Petawatt. With clever target designs, like structured curved cone targets, we have also been able to achieve major ion energy gains, leading to the highest energy laser-accelerated proton beams in the world. These new target designs promise to help usher in the next generation of particle sources realizing the potential of laser-accelerated beams.

  5. Design and Factory Test of the E /E- Frascati Linear Accelerator for DAFNE

    SciTech Connect (OSTI)

    Anamkath, H.; Lyons, S.; Nett, D.; Treas, P.; Whitham, K.; Zante, T.; /Titan Beta, Dublin; Miller, R.; /Titan Beta, Dublin /SLAC; Boni, R.; Hsieh, H.; Sannibale, F.; Vescovi, M.; Vignola, G.; /Frascati

    2011-11-28

    The electron-positron accelerator for the DAFNE project has been built and is in test at Titan Beta in Dublin, CA. This S-Band RF linac system utilizes four 45 MW sledded klystrons and 16-3 m accelerating structures to achieve the required performance. It delivers a 4 ampere electron beam to the positron converter and accelerates the resulting positrons to 550 MeV. The converter design uses a 4.3T pulsed tapered flux compressor along with a pseudo-adiabatic tapered field to a 5 KG solenoid over the first two positron accelerating sections. Quadrupole focusing is used after 100 MeV. The system performance is given in Table 1. This paper briefly describes the design and development of the various subassemblies in this system and gives the initial factory test data.

  6. SuperHILAC: Heavy-ion linear accelerator: Summary of capabilities, facilities, operations, and research

    SciTech Connect (OSTI)

    McDonald, R.J. (ed.)

    1987-09-01

    This report consists of a description of the accelerator facilities and a review of research programs being conducted there. Lists of SuperHILAC researchers and publications are also given.

  7. Efficient modelling of particle collisions using a non-linear viscoelastic contact force

    E-Print Network [OSTI]

    Ray, Shouryya; Fröhlich, Jochen

    2015-01-01

    In this paper the normal collision of spherical particles is investigated. The particle interaction is modelled in a macroscopic way using the Hertzian contact force with additional linear damping. The goal of the work is to develop an efficient approximate solution of sufficient accuracy for this problem which can be used in soft-sphere collision models for Discrete Element Methods and for particle transport in viscous fluids. First, by the choice of appropriate units, the number of governing parameters of the collision process is reduced to one, thus providing a dimensionless parameter that characterizes all such collisions up to dynamic similitude. It is a simple combination of known material parameters as well as initial conditions. A rigorous calculation of the collision time and restitution coefficient from the governing equations, in the form of a series expansion in this parameter is provided. Such a first principles calculation is particularly interesting from a theoretical perspective. Since the gov...

  8. Linear accelerator design study with direct plasma injection scheme for warm dense matter

    SciTech Connect (OSTI)

    Kondo, K.; Kanesue, T; Okamura, M.

    2011-03-28

    Warm Dense Matter (WDM) is a challenging science field, which is related to heavy ion inertial fusion and planetary science. It is difficult to expect the behavior because the state with high density and low temperature is completely different from ideal condition. The well-defined WDM generation is required to understand it. Moderate energy ion beams ({approx} MeV/u) slightly above Bragg peak is an advantageous method for WDM because of the uniform energy deposition. Direct Plasma Injection Scheme (DPIS) with a Interdigital H-mode (IH) accelerator has a potential for the beam parameter. We show feasible parameters of the IH accelerator for WDM. WDM physics is a challenging science and is strongly related to Heavy Ion Fusion science. WDM formation by Direct Plasma Injection Scheme (DPIS) with IH accelerator, which is a compact system, is proposed. Feasible parameters for IH accelerator are shown for WDM state. These represents that DPIS with IH accelerator can access a different parameter region of WDM.

  9. Technical Challenges and Scientific Payoffs of Muon Beam Accelerators for Particle Physics

    E-Print Network [OSTI]

    Zisman, Michael S.

    2008-01-01

    effort toward the International Linear Collider. Looking tosuch as the International Linear Collider (ILC) [6].

  10. Simulation of the relativistic electron dynamics and acceleration in a linearly-chirped laser pulse

    E-Print Network [OSTI]

    Jisrawi, Najeh M; Salamin, Yousef I

    2014-01-01

    Theoretical investigations are presented, and their results are discussed, of the laser acceleration of a single electron by a chirped pulse. Fields of the pulse are modeled by simple plane-wave oscillations and a $\\cos^2$ envelope. The dynamics emerge from analytic and numerical solutions to the relativistic Lorentz-Newton equations of motion of the electron in the fields of the pulse. All simulations have been carried out by independent Mathematica and Python codes, with identical results. Configurations of acceleration from a position of rest as well as from injection, axially and sideways, at initial relativistic speeds are studied.

  11. Accelerated Particle Swarm Optimization and Support Vector Machine for Business Optimization and Applications

    E-Print Network [OSTI]

    Yang, Xin-She; Fong, Simon

    2012-01-01

    Business optimization is becoming increasingly important because all business activities aim to maximize the profit and performance of products and services, under limited resources and appropriate constraints. Recent developments in support vector machine and metaheuristics show many advantages of these techniques. In particular, particle swarm optimization is now widely used in solving tough optimization problems. In this paper, we use a combination of a recently developed Accelerated PSO and a nonlinear support vector machine to form a framework for solving business optimization problems. We first apply the proposed APSO-SVM to production optimization, and then use it for income prediction and project scheduling. We also carry out some parametric studies and discuss the advantages of the proposed metaheuristic SVM.

  12. SimTrack: A compact c++ code for particle orbit and spin tracking in accelerators

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

    Luo, Yun

    2015-08-29

    SimTrack is a compact c++ code of 6-d symplectic element-by-element particle tracking in accelerators originally designed for head-on beam–beam compensation simulation studies in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It provides a 6-d symplectic orbit tracking with the 4th order symplectic integration for magnet elements and the 6-d symplectic synchro-beam map for beam–beam interaction. Since its inception in 2009, SimTrack has been intensively used for dynamic aperture calculations with beam–beam interaction for RHIC. Recently, proton spin tracking and electron energy loss due to synchrotron radiation were added. In this article, I will present the code architecture,more »physics models, and some selected examples of its applications to RHIC and a future electron-ion collider design eRHIC.« less

  13. EA-1904: Linac Coherent Light Source II at Stanford Linear Accelerator Laboratory, San Mateo, California

    Broader source: Energy.gov [DOE]

    This EA evaluates the environmental impacts of the proposed construction of the Linac Coherent Light Source at SLAC National Accelerator Laboratory, Menlo Park, California. None available at this time. For more information, contact: Mr. Dave Osugi DOE SLAC Site Office 2575 Sand Hill Road, MS8A Menlo Park, CA 94025 E-mail: dave.osugi@sso.science.doe.gov

  14. Alignment tolerance of accelerating structures and corrections for future linear colliders

    SciTech Connect (OSTI)

    Kubo, K.; Adolphsen, C.; Bane, K.L.F.; Raubenheimer, T.O.; Thompson, K.A.

    1995-06-01

    The alignment tolerance of accelerating structures is estimated by tracking simulations. Both single-bunch and multi-bunch effects are taken into account. Correction schemes for controlling the single and multi-bunch emittance growth in the case of large misalignment are also tested by simulations.

  15. Production of .sup.64 Cu and other radionuclides using a charged-particle accelerator

    DOE Patents [OSTI]

    Welch, Michael J. (Creve Couer, MO); McCarthy, Deborah W. (Maryland Heights, MO); Shefer, Ruth E. (Newton, MA); Klinkowstein, Robert E. (Winchester, MA)

    2000-01-01

    Radionuclides are produced according to the present invention at commercially significant yields and at specific activities which are suitable for use in radiodiagnostic agents such as PET imaging agents and radiotherapeutic agents and/or compositions. In the method and system of the present invention, a solid target having an isotopically enriched target layer electroplated on an inert substrate is positioned in a specially designed target holder and irradiated with a charged-particle beam. The beam is preferably generated using an accelerator such as a biomedical cyclotron at energies ranging from about 5 MeV to about 25 MeV. The target is preferably directly irradiated, without an intervening attenuating foil, and with the charged particle beam impinging an area which substantially matches the target area. The irradiated target is remotely and automatically transferred from the target holder, preferably without transferring any target holder subassemblies, to a conveyance system which is preferably a pneumatic or hydraulic conveyance system, and then further transferred to an automated separation system. The system is effective for processing a single target or a plurality of targets. After separation, the unreacted target material can be recycled for preparation of other targets. In a preferred application of the invention, a biomedical cyclotron has been used to produce over 500 mCi of .sup.64 Cu having a specific activity of over 300 mCi/.mu.g Cu according to the reaction .sup.64 Ni(p,n).sup.64 Cu. These results indicate that accelerator-produced .sup.64 Cu is suitable for radiopharmaceutical diagnostic and therapeutic applications.

  16. Thermodynamics and higher order moments in SU(3) linear $?$-model with gluonic quasi-particles

    E-Print Network [OSTI]

    Abdel Nasser Tawfik; Niseem Magdy

    2014-11-07

    In framework of linear $\\sigma$-model (LSM) with three quark flavors, the chiral phase-diagram at finite temperature and density is investigated. At temperatures higher than the critical temperature ($ T_c $), we added to LSM the gluonic sector from the quasi-particle model (QPM), which assumes that the interacting gluons in the strongly interacting matter, the quark-gluon plasma (QGP), are phenomenologically the same as non-interacting massive quasi-particles. The dependence of the chiral condensates of strange and non-strange quarks on temperature and chemical potential is analysed. Then, we have calculated the thermodynamics in the new approach (combination of LSM and QPM). Confronting the results with recent lattice QCD simulations shows an excellent agreement in almost all thermodynamic quantities. The first and second order moments of particle multiplicity are studied in dependence on the chemical potential but at fixed temperature and on the chemical potential but at fixed temperature. These are implemented in characterizing the large fluctuations accompanying the chiral phase-transition. The results of first and second order moments are compared with the SU(3) Polyakov linear $\\sigma$-model (PLSM). Also, the resulting phase-diagrams deduced in PLSM and LSM$+$QPM are compared with each other.

  17. An Analytic Linear Accelerator Source Model for Monte Carlo dose calculations. II. Model Utilization in a GPU-based Monte Carlo Package and Automatic Source Commissioning

    E-Print Network [OSTI]

    Tian, Zhen; Li, Yongbao; Shi, Feng; Jiang, Steve B; Jia, Xun

    2015-01-01

    We recently built an analytical source model for GPU-based MC dose engine. In this paper, we present a sampling strategy to efficiently utilize this source model in GPU-based dose calculation. Our source model was based on a concept of phase-space-ring (PSR). This ring structure makes it effective to account for beam rotational symmetry, but not suitable for dose calculations due to rectangular jaw settings. Hence, we first convert PSR source model to its phase-space let (PSL) representation. Then in dose calculation, different types of sub-sources were separately sampled. Source sampling and particle transport were iterated. So that the particles being sampled and transported simultaneously are of same type and close in energy to alleviate GPU thread divergence. We also present an automatic commissioning approach to adjust the model for a good representation of a clinical linear accelerator . Weighting factors were introduced to adjust relative weights of PSRs, determined by solving a quadratic minimization ...

  18. Feasibility of an XUV FEL Oscillator Driven by a SCRF Linear Accelerator

    SciTech Connect (OSTI)

    Lumpkin, A. H.; Freund, H. P.; Reinsch, M.

    2014-01-01

    The Advanced Superconducting Test Accelerator (ASTA) facility is currently under construction at Fermi National Accelerator Laboratory. Using a1-ms-long macropulse composed of up to 3000 micropulses, and with beam energies projected from 45 to 800 MeV, the possibility for an extreme ultraviolet (XUV) free-electron laser oscillator (FELO) with the higher energy is evaluated. We have used both GINGER with an oscillator module and the MEDUSA/OPC code to assess FELO saturation prospects at 120 nm, 40 nm, and 13.4 nm. The results support saturation at all of these wavelengths which are also shorter than the demonstrated shortest wavelength record of 176 nm from a storage-ring-based FELO. This indicates linac-driven FELOs can be extended into this XUV wavelength regime previously only reached with single-pass FEL configurations.

  19. Resonance broadening due to particle scattering and mode-coupling in the quasi-linear relaxation of electron beams

    E-Print Network [OSTI]

    Bian, Nicolas H; Ratcliffe, Heather

    2015-01-01

    Of particular interest for radio and hard X-ray diagnostics of accelerated electrons during solar flares is the understanding of the basic non-linear mechanisms regulating the relaxation of electron beams propagating in turbulent plasmas. In this work, it is shown that in addition to scattering of beam electrons, scattering of the beam-generated Langmuir waves via for instance mode-coupling, can also result in broadening of the wave-particle resonance. We obtain a resonance-broadened version of weak-turbulence theory with mode-coupling to ion-sound modes. Resonance broadening is presented here as a unified framework which can quantitatively account for the reduction and possible suppression of the beam instability due to background scattering of the beam electrons themselves or due to scattering of the beam-generated Langmuir waves in fluctuating plasmas. Resonance broadening being essentially equivalent to smoothing of the electron phase-space distribution, it is used to construct an intuitive physical pictu...

  20. Beam dynamics study of a 30?MeV electron linear accelerator to drive a neutron source

    SciTech Connect (OSTI)

    Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik

    2014-02-14

    An experimental neutron facility based on 32?MeV/18.47?kW electron linac has been studied by means of PARMELA simulation code. Beam dynamics study for a traveling wave constant gradient electron accelerator is carried out to reach the preferential operation parameters (E?=?30?MeV, P?=?18?kW, dE/E?particles). The whole linac comprises mainly E-gun, pre-buncher, buncher, and 2 accelerating columns. A disk-loaded, on-axis-coupled, 2?/3-mode type accelerating rf cavity is considered for this linac. After numerous optimizations of linac parameters, 32?MeV beam energy is obtained at the end of the linac. As high electron energy is required to produce acceptable neutron flux. The final neutron flux is estimated to be 5?×?10{sup 11}?n/cm{sup 2}/s/mA. Future development will be the real design of a 30?MeV electron linac based on S band traveling wave.

  1. High Power Klystrons: Theory and Practice at the Stanford Linear Accelerator CenterPart I

    SciTech Connect (OSTI)

    Caryotakis, G.

    2004-12-15

    This is Part I of a two-part report on design and manufacturing methods used at SLAC to produce accelerator klystrons. Chapter 1 begins with the history and applications for klystrons, in both of which Stanford University was extensively involved. The remaining chapters review the theory of klystron operation, derive the principal formulae used in their design, and discuss the assumptions that they involve. These formulae are subsequently used in small-signal calculations of the frequency response of a particular klystron, whose performance is also simulated by two different computer codes. The results of calculations and simulations are compared to the actual performance of the klystron.

  2. Electron Shock Surfing Acceleration in Multidimensions: Two-dimensional Particle-In-Cell Simulation of Collisionless Perpendicular Shock

    E-Print Network [OSTI]

    Takanobu Amano; Masahiro Hoshino

    2008-09-02

    Electron acceleration mechanism at high Mach number collisionless shocks propagating in a weakly magnetized medium is investigated by a self-consistent two-dimensional particle-in-cell simulation. Simulation results show that strong electrostatic waves are excited via the electron-ion electrostatic two-stream instability at the leading edge of the shock transition region as in the case of earlier one-dimensional simulations. We observe strong electron acceleration that is associated with the turbulent electrostatic waves in the shock transition region. The electron energy spectrum in the shock transition region exhibits a clear power-law distribution with spectral index of $2.0 {\\rm -} 2.5$. By analyzing the trajectories of accelerated electrons, we find that the acceleration mechanism is very similar to shock surfing acceleration of ions. In contrast to the ion shock surfing, however, the energetic electrons are reflected by electron-scale electrostatic fluctuations in the shock transition region, but not by the ion-scale cross-shock electrostatic potential. The reflected electrons are then accelerated by the convective electric field in front of the shock. We conclude that the multidimensional effects as well as the self-consistent shock structure are essential for the strong electron acceleration at high Mach number shocks.

  3. Advances in Normal Conducting Accelerator Technology from the X-Band Linear Collider Program

    E-Print Network [OSTI]

    Adolphsen, Chris

    2005-01-01

    In the early 1990's, groups at SLAC and KEK began dedicated development of X-band (11.4 GHz) rf technology for a next generation, TeV-scale linear collider. The choice of a relatively high frequency, four times that of the SLAC 50 GeV Linac, was motivated by the cost benefits of having lower rf energy per pulse (hence fewer rf components) and reasonable efficiencies at high gradients (hence shorter linacs). However, to realize such savings requires operation at gradients and peak powers much higher than that hitherto achieved. During the past 15 years, these challenges were met through innovations on several fronts, and resulted in a viable rf system design for a linear collider. This paper reviews these achievements, which include developments in the generation and transport of high power rf, and new insights into high gradient limitations.

  4. Suppressing Thermal Energy Drift In The LLNL Flash X-Ray Accelerator Using Linear Disk Resistor Stacks

    SciTech Connect (OSTI)

    Kreitzer, B R; Houck, T L; Luchterhand, O C

    2011-07-19

    This paper addresses thermal drift in sodium thiosulfate liquid resistors and their replacement with linear disk resistors from HVR Advanced Power Components. Sodium thiosulfate resistors in the FXR induction linear accelerator application have a temperature coefficient of {approx}1.8%/C. The FXR Marx banks send an 8kJ pulse through eight 524 cm{sup 3} liquid resistors at a repetition rate of up to 1 every 45 seconds. Every pulse increases the temperature of the solution by {approx}0.4 C which produces a 0.7% change in resistance. The typical cooling rate is {approx}0.4 C per minute which results in {approx}0.1% energy drop per pulse during continuous pulsed operations. A radiographic accelerator is extraordinarily sensitive to energy variations. Changes in beam energy produce movement in beam transport, changes in spot size, and large dose variations. If self-heating were the only problem, we could predict the increase in input voltage required to compensate for the energy loss. However, there are other variables that influence the temperature of the resistors such as focus magnet heating, changes in room temperature, changes in cooling water, where the cell is located, etc. Additionally not all of the resistors have equivalent cooling rates and as many as 32 resistors are driven from a single power source. The FXR accelerator group elected to replace the sodium thiosulfate resistors with HVR Linear Disk Resistors in a stack type configuration. With data limited for these resistors when used in oil and at low resistance values, a full characterization needed to be performed. High currents (up to 15kA), high voltages (up to 400kV), and Fast Rise times (<10ns) made a resistor choice difficult. Other solid resistors have been tried and had problems at the connection points and with the fact that the resistivity changed as they absorbed oil. The selected HVR resistors have the advantage of being manufactured with the oil impregnated in to them so this characteristic is minimized while still offering the desired low temperature coefficient of resistance compared to sodium thiosulfate. The characterization experiments and comparison with the sodium thiosulfate liquid resistors will be fully discussed and the final design described.

  5. Vacuum effects of ultra-low mass particle account for Recent Acceleration of Universe

    E-Print Network [OSTI]

    Leonard Parker; Alpan Raval

    1999-08-04

    In recent work, we showed that non-perturbative vacuum effects of a very low mass particle could induce, at a redshift of order 1, a transition from a matter-dominated to an accelerating universe. In that work, we used the simplification of a sudden transition out of the matter-dominated stage and were able to fit the Type Ia supernovae (SNe-Ia) data points with a spatially-open universe. In the present work, we find a more accurate, smooth {\\it spatially-flat} analytic solution to the quantum-corrected Einstein equations. This solution gives a good fit to the SNe-Ia data with a particle mass parameter $m_h$ in the range $6.40 \\times 10^{-33}$ eV to $7.25 \\times 10^{-33}$ eV. It follows that the ratio of total matter density (including dark matter) to critical density, $\\O_0$, is in the range 0.58 to 0.15, and the age $t_0$ of the universe is in the range $8.10 h^{-1}$ Gyr to $12.2 h^{-1}$ Gyr, where $h$ is the present value of the Hubble constant, measured as a fraction of the value 100 km/(s Mpc). This spatially-flat model agrees with estimates of the position of the first acoustic peak in the small angular scale fluctuations of the cosmic background radiation, and with light-element abundances of standard big-bang nucleosynthesis. Our model has only a single free parameter, $m_h$, and does not require that we live at a special time in the evolution of the universe.

  6. From laser particle acceleration to the synthesis of extremely neutron rich isotopes via the novel fission-fusion mechanism

    SciTech Connect (OSTI)

    Thirolf, P. G.

    2015-02-24

    High-power, short pulse lasers have emerged in the last decade as attractive tools for accelerating charged particles (electrons, ions) to high energies over mm-scale acceleration lengths, thus promising to rival conventional acceleration techniques in the years ahead. In the first part of the article, the principles of laser-plasma interaction as well as the techniques and the current status of the acceleration of electron and ion beams will be briefly introduced. In particular with the upcoming next generation of multi-PW class laser systems, such as the one under construction for the ELI-Nuclear Physics project in Bucharest (ELI-NP), very efficient acceleration mechanisms for brilliant ion beams like radiation pressure acceleration (RPA) come into reach. Here, ultra-dense ion beams reaching solid-state density can be accelerated from thin target foils, exceeding the density of conventionally accelerated ion beams by about 14 orders of magnitude. This unique property of laser-accelerated ion beams can be exploited to explore the scenario of a new reaction mechanism called ‘fission-fusion’, which will be introduced in the second part of the article. Accelerating fissile species (e.g. {sup 232}Th) towards a second layer of the same material will lead to fission both of the beam-like and target-like particles. Due to the close to solid-state density of the accelerated ion bunches, fusion may occur between neutron-rich (light) fission products. This may open an access path towards extremely neutron-rich nuclides in the vicinity of the N=126 waiting point of the astrophysical r process. ‘Waiting points’ at closed nucleon shells play a crucial role in controlling the reaction rates. However, since most of the pathway of heavy-element formation via the rapid-neutron capture process (r-process) runs in ‘terra incognita’ of the nuclear landscape, in particular the waiting point at N=126 is yet unexplored and will remain largely inaccessible to conventional nuclear reaction schemes even at next-generation radioactive beam facilities, underlining the attractive perspectives offered, e.g., by ELI-NP.

  7. Tidal Charged Black Holes as Particle Accelerators to Arbitrarily High Energy

    E-Print Network [OSTI]

    Pradhan, Parthapratim

    2014-01-01

    We show that Randall Sundrum tidal charged spherically symmetric vacuum brane black holes could be act as a particle accelerator with ultrahigh center-of-mass energy in the limiting case of \\emph{ maximal black hole tidal charge}. For non-extremal Randall Sundrum tidal charged black hole, the center-of-mass energy is finite. While for maximally Randall Sundrum tidal charged black hole, the center-of-mass energy is \\emph{infinite}. We have also derived the center-of-mass energy at ISCO(Innermost Stable Circular Orbit) or LSCO(Last Stable Circular Orbit) or MSCO(Marginally Stable Circular Orbit) and MBCO (Marginally Bound Circular Orbit) for maximally Randall Sundrum tidal charged black hole. We show visually the differences between Reissner-Nordstr{\\o}m black hole and Randall Sundrum tidal charged BH. We have found that for maximally Randall Sundrum tidal charged black hole the center-of-mass energy is satisfied the following inequality: $E_{cm}\\mid_{r_{+}}>E_{cm}\\mid_{r_{mb}}>E_{cm}\\mid_{r_{ISCO}}$ i.e. $E_{c...

  8. Tidal Charged Black Holes as Particle Accelerators to Arbitrarily High Energy

    E-Print Network [OSTI]

    Parthapratim Pradhan

    2014-12-28

    We show that Randall Sundrum tidal charged spherically symmetric vacuum brane black holes could be act as a particle accelerator with ultrahigh center-of-mass energy in the limiting case of \\emph{ maximal black hole tidal charge}. For non-extremal Randall Sundrum tidal charged black hole, the center-of-mass energy is finite. While for maximally Randall Sundrum tidal charged black hole, the center-of-mass energy is \\emph{infinite}. We have also derived the center-of-mass energy at ISCO(Innermost Stable Circular Orbit) or LSCO(Last Stable Circular Orbit) or MSCO(Marginally Stable Circular Orbit) and MBCO (Marginally Bound Circular Orbit) for maximally Randall Sundrum tidal charged black hole. We show visually the differences between Reissner-Nordstr{\\o}m black hole and Randall Sundrum tidal charged BH. We have found that for maximally Randall Sundrum tidal charged black hole the center-of-mass energy is satisfied the following inequality: $E_{cm}\\mid_{r_{+}}>E_{cm}\\mid_{r_{mb}}>E_{cm}\\mid_{r_{ISCO}}$ i.e. $E_{cm}\\mid_{r_{+} = \\frac{M}{M_{p}^2}}: E_{cm}\\mid_{r_{mb} = \\left(\\frac{3+\\sqrt{5}}{2}\\right)\\frac{M}{M_{p}^2}}:E_{cm}\\mid_{r_{ISCO} = 4\\frac{M}{M_{p}^2}} = \\infty: 3.23 : 2.6$. Which is exactly \\emph{similar} to the spherically symmetric extreme Reissner-Nordstr\\"{o}m black hole.}

  9. Optical Effects of Wakefields in the PEP-II Stanford Linear Accelerator Center B Factory

    SciTech Connect (OSTI)

    Heifets, S.; Novokhatski, S.; Teytelman, D.; /SLAC

    2007-01-29

    Wakefields defining beam stability affect also the beam optics and beam properties in high current machines. In this paper we present observations and analysis of the optical effects in the PEP-II SLAC B-factory, which has the record in achievement of high electron and positron currents. We study the synchronous phase and the bunch length variation along the train of bunches, overall bunch lengthening and effects of the wakes on the tune and on the Twiss parameters. This analysis is being used in upgrades of PEP-II and may be applied to future B-factories and damping rings for Linear Colliders.

  10. Spontaneous emergence of non-planar electron orbits during direct laser acceleration by a linearly polarized laser pulse

    E-Print Network [OSTI]

    Arefiev, A V; Robinson, A P L; Shvets, G; Willingale, L

    2015-01-01

    An electron irradiated by a linearly polarized relativistic intensity laser pulse in a cylindrical plasma channel can gain significant energy from the pulse. The laser electric and magnetic fields drive electron oscillations in a plane making it natural to expect the electron trajectory to be flat. We show that strong modulations of the relativistic $\\gamma$-factor associated with the energy enhancement cause the free oscillations perpendicular to the plane of the driven motion to become unstable. As a consequence, out of plane displacements grow to become comparable to the amplitude of the driven oscillations and the electron trajectory becomes essentially three-dimensional, even if at an early stage of the acceleration it was flat. The development of the instability profoundly affects the x-ray emission, causing considerable divergence of the radiation perpendicular to the plane of the driven oscillations, while also reducing the overall emitted energy.

  11. Efficient modelling of particle collisions using a non-linear viscoelastic contact force

    E-Print Network [OSTI]

    Shouryya Ray; Tobias Kempe; Jochen Fröhlich

    2015-06-21

    In this paper the normal collision of spherical particles is investigated. The particle interaction is modelled in a macroscopic way using the Hertzian contact force with additional linear damping. The goal of the work is to develop an efficient approximate solution of sufficient accuracy for this problem which can be used in soft-sphere collision models for Discrete Element Methods and for particle transport in viscous fluids. First, by the choice of appropriate units, the number of governing parameters of the collision process is reduced to one, which is a simple combination of known material parameters as well as initial conditions. It provides a dimensionless parameter that characterizes all such collisions up to dynamic similitude. Next, a rigorous calculation of the collision time and restitution coefficient from the governing equations, in the form of a series expansion in this parameter is provided. Such a calculation based on first principles is particularly interesting from a theoretical perspective. Since the governing equations present some technical difficulties, the methods employed are also of interest from the point of view of the analytical technique. Using further approximations, compact expressions for the restitution coefficient and the collision time are then provided. These are used to implement an approximate algebraic rule for computing the desired stiffness and damping in the framework of the adaptive collision model (Kempe & Fr\\"{o}hlich, J. Fluid Mech., 709: 445-489, 2012). Numerical tests with binary as well as multiple particle collisions are reported to illustrate the accuracy of the proposed method and its superiority in terms of numerical efficiency.

  12. The International Linear Collider

    E-Print Network [OSTI]

    Marco Battaglia

    2007-05-28

    The International Linear Collider (ILC) is the next large scale project in accelerator particle physics. Colliding electrons with positrons at energies from 0.3 TeV up to about 1 TeV, the ILC is expected to provide the accuracy needed to complement the LHC data and extend the sensitivity to new phenomena at the high energy frontier and answer some of the fundamental questions in particle physics and in its relation to Cosmology. This paper reviews some highlights of the ILC physics program and some of the major challenges for the accelerator and detector design.

  13. Theoretical and experimental analysis of a linear accelerator endowed with single feed coupler with movable short-circuit

    SciTech Connect (OSTI)

    Forno, Massimo Dal [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy) [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy); Department of Engineering and Architecture, University of Trieste, Trieste (Italy); Craievich, Paolo [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy) [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy); P.S.I. (Paul Scherrer Institute), Villigen (Switzerland); Penco, Giuseppe [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy)] [Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy); Vescovo, Roberto [Department of Engineering and Architecture, University of Trieste, Trieste (Italy)] [Department of Engineering and Architecture, University of Trieste, Trieste (Italy)

    2013-11-15

    The front-end injection systems of the FERMI@Elettra linac produce high brightness electron beams that define the performance of the Free Electron Laser. The photoinjector mainly consists of the radiofrequency (rf) gun and of two S-band rf structures which accelerate the beam. Accelerating structures endowed with a single feed coupler cause deflection and degradation of the electron beam properties, due to the asymmetry of the electromagnetic field. In this paper, a new type of single feed structure with movable short-circuit is proposed. It has the advantage of having only one waveguide input, but we propose a novel design where the dipolar component is reduced. Moreover, the racetrack geometry allows to reduce the quadrupolar component. This paper presents the microwave design and the analysis of the particle motion inside the linac. A prototype has been machined at the Elettra facility to verify the new coupler design and the rf field has been measured by adopting the bead-pull method. The results are here presented, showing good agreement with the expectations.

  14. Linear gyrokinetic particle-in-cell simulations of Alfven instabilities in tokamaks

    E-Print Network [OSTI]

    Biancalani, A; Briguglio, S; Koenies, A; Lauber, Ph; Mishchenko, A; Poli, E; Scott, B D; Zonca, F

    2015-01-01

    The linear dynamics of Alfven modes in tokamaks is investigated here by means of the global gyrokinetic particle-in-cell code NEMORB. The model equations are shown and the local shear Alfven wave dispersion relation is derived, recovering the continuous spectrum in the incompressible ideal MHD limit. A verification and benchmark analysis is performed for continuum modes in a cylinder and for toroidicity-induced Alfven Eigenmodes. Modes in a reversed-shear equilibrium are also investigated, and the dependence of the spatial structure in the poloidal plane on the equilibrium parameters is described. In particular, a phase-shift in the poloidal angle is found to be present for modes whose frequency touches the continuum, whereas a radial symmetry is found to be characteristic of modes in the continuum gap.

  15. Self-interaction in the Bopp–Podolsky electrodynamics: Can the observable mass of a charged particle depend on its acceleration?

    SciTech Connect (OSTI)

    Zayats, Alexei E., E-mail: Alexei.Zayats@kpfu.ru

    2014-03-15

    In this paper we obtain the expression for the self-force in the model with the Lagrangian containing additional terms, quadratic in Maxwell tensor derivatives (so-called Bopp–Podolsky electrodynamics). Features of this force are analyzed for various limiting cases. When a charged particle moves along straight line with a uniform acceleration, an explicit formula is found. In the framework of the considered model, an observable renormalized particle mass is shown to depend on its acceleration. This dependence allows, in principle, to extract experimentally a value of the particle bare mass. -- Highlights: •An expression for the self-force in the Bopp–Podolsky electrodynamics is given. •For a uniformly accelerated charged particle an explicit formula for the self-force is obtained. •Dependence between the observable mass of a charged particle and its acceleration is found.

  16. Laser-driven plasma-based accelerators: Wakefield excitation, channel guiding, and laser triggered particle injection*

    E-Print Network [OSTI]

    Wurtele, Jonathan

    Laser-driven plasma-based accelerators: Wakefield excitation, channel guiding, and laser triggered; accepted 18 February 1998 Plasma-based accelerators are discussed in which high-power short pulse lasers are the power source, suitably tailored plasma structures provide guiding of the laser beam and support large

  17. FOCUSING IN LINEAR ACCELERATORS

    E-Print Network [OSTI]

    McMillan, Edwin M.

    2008-01-01

    sponsored by the Atomic Energy Commission. Infozmation D i vP r o j e c t Atomic Energy Commission - Washington B a t t

  18. Muon acceleration in cosmic-ray sources

    SciTech Connect (OSTI)

    Klein, Spencer R.; Mikkelsen, Rune E. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Becker Tjus, Julia [Fakultät für Physik and Astronomie, Theoretische Physik I, Ruhr-Universität Bochum, D-44780 Bochum (Germany)

    2013-12-20

    Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in gamma-ray bursts, magnetars, or other sources. These transient sources have short lifetimes, which necessitate very high accelerating gradients, up to 10{sup 13} keV cm{sup –1}. At gradients above 1.6 keV cm{sup –1}, muons produced by hadronic interactions undergo significant acceleration before they decay. This muon acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. Using the IceCube high-energy diffuse neutrino flux limits, we set two-dimensional limits on the source opacity and matter density, as a function of accelerating gradient. These limits put strong constraints on different models of particle acceleration, particularly those based on plasma wake-field acceleration, and limit models for sources like gamma-ray bursts and magnetars.

  19. Three-dimensional simulations of the non-thermal broadband emission from young supernova remnants including efficient particle acceleration

    SciTech Connect (OSTI)

    Ferrand, Gilles; Safi-Harb, Samar [Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Decourchelle, Anne, E-mail: gferrand@physics.umanitoba.ca, E-mail: samar@physics.umanitoba.ca, E-mail: anne.decourchelle@cea.fr [Laboratoire AIM (CEA/Irfu, CNRS/INSU, Université Paris VII), CEA Saclay, bât. 709, F-91191 Gif sur Yvette (France)

    2014-07-01

    Supernova remnants are believed to be major contributors to Galactic cosmic rays. In this paper, we explore how the non-thermal emission from young remnants can be used to probe the production of energetic particles at the shock (both protons and electrons). Our model couples hydrodynamic simulations of a supernova remnant with a kinetic treatment of particle acceleration. We include two important back-reaction loops upstream of the shock: energetic particles can (1) modify the flow structure and (2) amplify the magnetic field. As the latter process is not fully understood, we use different limit cases that encompass a wide range of possibilities. We follow the history of the shock dynamics and of the particle transport downstream of the shock, which allows us to compute the non-thermal emission from the remnant at any given age. We do this in three dimensions, in order to generate projected maps that can be compared with observations. We observe that completely different recipes for the magnetic field can lead to similar modifications of the shock structure, although to very different configurations of the field and particles. We show how this affects the emission patterns in different energy bands, from radio to X-rays and ?-rays. High magnetic fields (>100 ?G) directly impact the synchrotron emission from electrons, by restricting their emission to thin rims, and indirectly impact the inverse Compton emission from electrons and also the pion decay emission from protons, mostly by shifting their cut-off energies to respectively lower and higher energies.

  20. Selected topics in particle accelerators: Proceedings of the CAP meetings. Volume 4

    SciTech Connect (OSTI)

    Parsa, Z.

    1995-10-01

    This Report includes copies of transparencies and notes from the presentations made at the Center for Accelerator Physics at Brookhaven National Laboratory. Editing and changes to the authors` contributions in this Report were made only to fulfill the publication requirements. This volume includes notes and transparencies on eight presentations: ``Application of Accelerator-Driven Spallation Targets - Including Tritium Production and Nuclear Waste Transmutation``, ``BNL 5 MW Pulsed Spallation Neutron Source Study``, ``Designing and Understanding of Magnets with the Help of Conformal Mapping``, ``Laser - Electron Beam Scattering Coherent Compton X-Ray Sources``, ``The LHC Project``, ``Optimization of the Photocathode-Linac Separation for the ATF [Accelerator Test Facility] Injection System``, ``On CEBAF Commissioning: First Results``, and ``The Proposed Booster Application Facility at BNL``. An Appendix lists dates, topics, and speakers from October 1989 to December 1994.

  1. The effect of a paraffin screen on the neutron dose at the maze door of a 15 MV linear accelerator

    SciTech Connect (OSTI)

    Krmar, M.; Kuzmanovi?, A. [Physics Department, Faculty of Science, University of Novi Sad, Novi Sad 21000 (Serbia)] [Physics Department, Faculty of Science, University of Novi Sad, Novi Sad 21000 (Serbia); Nikoli?, D. [National Institute for Nanotechnology, Edmonton, Alberta T6G 2M9 (Canada)] [National Institute for Nanotechnology, Edmonton, Alberta T6G 2M9 (Canada); Kuzmanovi?, Z. [International Medical Centers, Banja Luka 78000, Republika Srpska, Bosnia and Herzegovina (Bosnia and Herzegowina)] [International Medical Centers, Banja Luka 78000, Republika Srpska, Bosnia and Herzegovina (Bosnia and Herzegowina); Ganezer, K. [Physics Department, California State University Dominguez Hills, Carson, California 90747 (United States)] [Physics Department, California State University Dominguez Hills, Carson, California 90747 (United States)

    2013-08-15

    Purpose: The purpose of this study was to explore the effects of a paraffin screen located at various positions in the maze on the neutron dose equivalent at the maze door.Methods: The neutron dose equivalent was measured at the maze door of a room containing a 15 MV linear accelerator for x-ray therapy. Measurements were performed for several positions of the paraffin screen covering only 27.5% of the cross-sectional area of the maze. The neutron dose equivalent was also measured at all screen positions. Two simple models of the neutron source were considered in which the first assumed that the source was the cross-sectional area at the inner entrance of the maze, radiating neutrons in an isotropic manner. In the second model the reduction in the neutron dose equivalent at the maze door due to the paraffin screen was considered to be a function of the mean values of the neutron fluence and energy at the screen.Results: The results of this study indicate that the equivalent dose at the maze door was reduced by a factor of 3 through the use of a paraffin screen that was placed inside the maze. It was also determined that the contributions to the dosage from areas that were not covered by the paraffin screen as viewed from the dosimeter, were 2.5 times higher than the contributions from the covered areas. This study also concluded that the contributions of the maze walls, ceiling, and floor to the total neutron dose equivalent were an order of magnitude lower than those from the surface at the far end of the maze.Conclusions: This study demonstrated that a paraffin screen could be used to reduce the neutron dose equivalent at the maze door by a factor of 3. This paper also found that the reduction of the neutron dose equivalent was a linear function of the area covered by the maze screen and that the decrease in the dose at the maze door could be modeled as an exponential function of the product ?·E at the screen.

  2. Accelerator dynamics and beam aperture

    SciTech Connect (OSTI)

    Parsa, Z.

    1986-10-01

    We present an analytical method for analyzing accelerator dynamics, including higher order effects of multipoles on the beam. This formalism provides a faster alternative to particle tracking. Simplectic expressions for the emittance and phase describing the dynamical behavior of a particle in a circular accelerator are derived using second order perturbation theory (in the presence of nonlinear elements, e.g., sextupoles, octupoles). These expressions are successfully used to calculate the emittance growth, smear and linear aperture. Our findings compare well with results obtained from tracking programs. In addition perturbation to betatron tune; resonance strengths; stop bandwidth; fixed points; island width; and Chirikov criteria are calculated.

  3. Lagrangian Measurements of Inertial Particle Accelerations in Grid Generated Wind Tunnel Turbulence

    E-Print Network [OSTI]

    Gylfason, Ármann

    (where the particle-fluid density ratio is order 1000), or fuel drops in combustors, respond exponential tails that are narrower than those of a fluid particles (St 0) and there is a decrease selectively sample the fluid field and are less likely to experience regions of the fluid undergoing

  4. PARTICLE ACCELERATION IN A THREE-DIMENSIONAL MODEL OF RECONNECTING CORONAL MAGNETIC FIELDS

    E-Print Network [OSTI]

    Isliker, Heinz

    , Denmark (Author for correspondence: E-mail: p.cargill@imperial.ac.uk) (Received 11 July 2005; Accepted dimensional MHD models lead to the production of relativistic particles on sub-second timescales with power, particles gain energy by multiple interactions with many current sheets. Difficulties that need

  5. Correlation of pulsar radio emission spectrum with peculiarities of particle acceleration in a polar gap

    SciTech Connect (OSTI)

    Kontorovich, V. M. Flanchik, A. B.

    2013-01-15

    The analytical expression for the frequency of radio emission intensity maximum in pulsars with free electron emission from the stellar surface has been found. Peculiarities of the electron acceleration in a polar gap are considered. The correlation between the high-frequency cutoff and low-frequency turnover in the radio emission spectrum of pulsars known from observations has been explained.

  6. Theoretical and observational analysis of particle acceleration mechanisms at astrophysical shocks

    E-Print Network [OSTI]

    Lever, Edward Lawrence

    2011-01-01

    linear dependence on wave energy density and right panelc motion. Extrapolating the wave energy to unity as observedfactor ? C / v ? and the wave energy by way of the magnetic

  7. Small-scale magnetic islands in the solar wind and their role in particle acceleration. Part 1: Dynamics of magnetic islands near the heliospheric current sheet

    E-Print Network [OSTI]

    Khabarova, O; Li, G; Roux, J A le; Webb, G M; Dosch, A; Malandraki, O E

    2015-01-01

    Increases of ion fluxes in the keV-MeV range are sometimes observed near the heliospheric current sheet (HCS) during periods when other sources are absent. These resemble solar energetic particle (SEP) events, but the events are weaker and apparently local. Conventional explanations based on either shock acceleration of charged particles or particle acceleration due to magnetic reconnection at interplanetary current sheets are not persuasive. We suggest instead that recurrent magnetic reconnection occurs at the HCS and smaller current sheets in the solar wind (Zharkova & Khabarova 2012), of which a consequence is particle energization by the dynamically evolving secondary current sheets and magnetic islands (Zank et al. 2014; Drake et al. 2006a). The effectiveness of the trapping and acceleration process associated with magnetic islands depends in part on the topology of the HCS. We show that the HCS possesses ripples superimposed on the large-scale flat or wavy structure. We conjecture that the ripples c...

  8. Particle Acceleration and Gamma-ray emission due to magnetic reconnection in the core region of radio galaxies

    E-Print Network [OSTI]

    Khiali, Behrouz; Sol, Hélène

    2015-01-01

    The current detectors of gamma-ray emission have too poor resolution to determine whether this emission is produced in the jet or in the core, specially of low luminous, non-blazar AGNs (as radio galaxies). In recent works it has been found that the power released by events of turbulent fast magnetic reconnection in the core region of these sources is more than sufficient to reproduce the observed gamma-ray luminosities. Besides, 3D MHD simulations with test particles have demonstrated that a first-order Fermi process within reconnection sites with embedded turbulence results very efficient particle acceleration rates. Employing this acceleration mechanism and the model above, and considering the relevant leptonic and hadronic loss processes in the core region, we computed the spectral energy distribution (SED) of radio galaxies for which very high energy (VHE) emission has been detected (namely, M87, Cen A, Per A, and IC 310). We found that these match very well specially with the VHE observations, therefore...

  9. User's manual for ONEDANT: a code package for one-dimensional, diffusion-accelerated, neutral-particle transport

    SciTech Connect (OSTI)

    O'Dell, R.D.; Brinkley, F.W. Jr.; Marr, D.R.

    1982-02-01

    ONEDANT is designed for the CDC-7600, but the program has been implemented and run on the IBM-370/190 and CRAY-I computers. ONEDANT solves the one-dimensional multigroup transport equation in plane, cylindrical, spherical, and two-angle plane geometries. Both regular and adjoint, inhomogeneous and homogeneous (k/sub eff/ and eigenvalue search) problems subject to vacuum, reflective, periodic, white, albedo, or inhomogeneous boundary flux conditions are solved. General anisotropic scattering is allowed and anisotropic inhomogeneous sources are permitted. ONEDANT numerically solves the one-dimensional, multigroup form of the neutral-particle, steady-state form of the Boltzmann transport equation. The discrete-ordinates approximation is used for treating the angular variation of the particle distribution and the diamond-difference scheme is used for phase space discretization. Negative fluxes are eliminated by a local set-to-zero-and-correct algorithm. A standard inner (within-group) iteration, outer (energy-group-dependent source) iteration technique is used. Both inner and outer iterations are accelerated using the diffusion synthetic acceleration method. (WHK)

  10. Particle acceleration and radiation friction effects in the filamentation instability of pair plasmas

    E-Print Network [OSTI]

    D'Angelo, M; Sgattoni, A; Pegoraro, F; Macchi, A

    2015-01-01

    The evolution of the filamentation instability produced by two counter-streaming pair plasmas is studied with particle-in-cell (PIC) simulations in both one (1D) and two (2D) spatial dimensions. Radiation friction effects on particles are taken into account. After an exponential growth of both the magnetic field and the current density, a nonlinear quasi-stationary phase sets up characterized by filaments of opposite currents. During the nonlinear stage, a strong broadening of the particle energy spectrum occurs accompanied by the formation of a peak at twice their initial energy. A simple theory of the peak formation is presented. The presence of radiative losses does not change the dynamics of the instability but affects the structure of the particle spectra.

  11. Diffusive Shock Acceleration: the Fermi Mechanism

    E-Print Network [OSTI]

    Matthew G. Baring

    1997-11-16

    The mechanism of diffusive Fermi acceleration at collisionless plasma shock waves is widely invoked in astrophysics to explain the appearance of non-thermal particle populations in a variety of environments, including sites of cosmic ray production, and is observed to operate at several sites in the heliosphere. This review outlines the principal results from the theory of diffusive shock acceleration, focusing first on how it produces power-law distributions in test-particle regimes, where the shock dynamics are dominated by the thermal populations that provide the seed particles for the acceleration process. Then the importance of non-linear modifications to the shock hydrodynamics by the accelerated particles is addressed, emphasizing how these subsequently influence non-thermal spectral formation.

  12. Selected topics in particle accelerators: Proceedings of the CAP meetings. Volume 3

    SciTech Connect (OSTI)

    Parsa, Z. [ed.] [comp.

    1995-10-01

    This Report includes copies of transparencies and notes from the presentations made at the Center for Accelerator Physics at Brookhaven National Laboratory. Editing and changes to authors` contributions in this Report were made only to fulfill the publication requirements. This volume includes notes and transparencies on eight presentations: ``Inverse Cherenkov Laser Acceleration of Electron Beams``, ``High Brightness Field Emission Cathodes``, ``QCD/Teraflop Collaboration: The Future of Supercomputing``, ``Report on Dipole R&D``, ``Reaching Maximum Luminosity in Hadron Colliders at 10-100 TeV``, ``STAR Collaboration Project Status Report: Quarks and Gluons``, ``PHENIX Collaboration Project Status Report``, and ``Update on Status of BNL Relativistic Heavy Ion Collider (RHIC) Project: RHIC Design Issues.``

  13. Acceleration and Compression of Charged Particle Bunches Using Counter-Propagating Laser Beams

    SciTech Connect (OSTI)

    G. Shvets; N. J. Fisch; A. Pukhov

    2000-10-17

    The nonlinear interaction between counter-propagating laser beams in a plasma results in the generation of large (enhanced) plasma wakes. The two beams need to be slightly detuned in frequency, and one of them has to be ultra-short (shorter than a plasma period). Thus produced wakes have a phase velocity close to the speed of light and can be used for acceleration and compression of charged bunches. The physical mechanism responsible for the enhanced wake generation is qualitatively described and compared with the conventional laser wakefield mechanism. The authors also demonstrate that, depending on the sign of the frequency difference between the lasers, the enhanced wake can be used as a ``snow-plow'' to accelerate and compress either positively or negatively charged bunches. This ability can be utilized in an electron-positron injector.

  14. Particle-in-cell simulations of particle energization via shock drift acceleration from low Mach number quasi-perpendicular shocks in solar flares

    E-Print Network [OSTI]

    Park, Jaehong; Workman, Jared C; Blackman, Eric G

    2012-01-01

    Low Mach number, high beta fast mode shocks can occur in the magnetic reconnection outflows of solar flares. These shocks, which occur above flare loop tops, may provide the electron energization responsible for some of the observed hard X-rays and contemporaneous radio emission. Here we present new 2D particle-in-cell simulations of low Mach number/high beta quasi-perpendicular shocks. The simulations show that electrons above a certain energy threshold experience shock-drift-acceleration. The transition energy between the thermal and non-thermal spectrum and the spectral index from the simulations are consistent with some of the X-ray spectra from RHESSI in the energy regime, $E\\lesssim 40\\sim 100$ keV. Plasma instabilities associated with the shock structure such as the modified-two-stream and the electron whistler/mirror instabilities are examined and compared with the numerical solutions of the kinetic dispersion relations.

  15. Condensed Surfaces of Magnetic Neutron Stars, Thermal Surface Emission, and Particle Acceleration Above Pulsar Polar Caps

    E-Print Network [OSTI]

    Zach Medin; Dong Lai

    2008-01-18

    For sufficiently strong magnetic fields and/or low temperatures, the neutron star surface may be in a condensed state with little gas or plasma above it. Such surface condensation can significantly affect the thermal emission from isolated neutron stars, and may lead to the formation of a charge-depleted acceleration zone ("vacuum gap") in the magnetosphere above the stellar polar cap. Using the latest results on the cohesive property of magnetic condensed matter, we quantitatively determine the conditions for surface condensation and vacuum gap formation in magnetic neutron stars. We find that condensation can occur if the thermal energy kT of the neutron star surface is less than about 8% of its cohesive energy Q_s, and that a vacuum gap can form if the neutron star's rotation axis and magnetic moment point in opposite directions and kT is less than about 4% of Q_s. Thus, vacuum gap accelerators may exist for some neutron stars. Motivated by this result, we also study the physics of pair cascades in the vacuum gap model for photon emission by accelerating electrons and positrons due to both curvature radiation and resonant/nonresonant inverse Compton scattering. Our calculations of the condition of cascade-induced vacuum breakdown and the related pulsar death line/boundary generalize previous works to the superstrong field regime. We find that inverse Compton scatterings do not produce a sufficient number of high energy photons in the gap and thus do not lead to pair cascades for most neutron star parameters. We discuss the implications of our results for the recent observations of neutron star thermal radiation as well as for the detection/non-detection of radio emission from high-B pulsars and magnetars.

  16. Accelerator measurements of magnetically-induced radio emission from particle cascades with applications to cosmic-ray air showers

    E-Print Network [OSTI]

    K. Belov; K. Mulrey; A. Romero-Wolf; S. A. Wissel; A. Zilles; K. Bechtol; K. Borch; P. Chen; J. Clem; P. W. Gorham; C. Hast; T. Huege; R. Hyneman; K. Jobe; K. Kuwatani; J. Lam; T. Liu; J. Nam; C. Naudet; R. Nichol; B. F. Rauch; B. Rotter; D. Saltzberg; H. Schoorlemmer; D. Seckel; B. Strutt; A. G. Vieregg; C. Williams

    2015-07-27

    An experiment at SLAC provides the first beam test of radio-frequency (RF) radiation from a charged particle cascade in the presence of a magnetic field (up to $\\sim$1~kG), a model system for RF emission from a cosmic-ray air shower. This experiment provides a suite of controlled laboratory measurements to compare to particle-level simulations of RF emission, which are relied upon in ultra-high-energy cosmic-ray air shower detection. We compare simulations to data for intensity, linearity with magnetic field, angular distribution, polarization, and spectral content. In particular, we confirm recent predictions that the magnetically induced emission forms a beam that peaks at the Cherenkov angle and show that the simulations reproduce the data within systematic uncertainties.

  17. Shock Acceleration of the Energetic Particle Background in the Solar Wind David T. Sodaitis

    E-Print Network [OSTI]

    on planet Earth, the solar wind is an important topic for study because it is strongly influenced by solar activity, and it transfers that solar influence "to planets, comets, dust particles, and cosmic rays of three components, a fluid model of the sun's corona which in it's equilibrium state creates a supersonic

  18. Radiation Heat Transfer in Particle-Laden Gaseous Flame: Flame Acceleration and Triggering Detonation

    E-Print Network [OSTI]

    Liberman, M A; Kiverin, A D

    2015-01-01

    In this study we examine influence of the radiation heat transfer on the combustion regimes in the mixture, formed by suspension of fine inert particles in hydrogen gas. The gaseous phase is assumed to be transparent for the thermal radiation, while the radiant heat absorbed by the particles is then lost by conduction to the surrounding gas. The particles and gas ahead of the flame is assumed to be heated by radiation from the original flame. It is shown that the maximum temperature increase due to the radiation preheating becomes larger for a flame with lower velocity. For a flame with small enough velocity temperature of the radiation preheating may exceed the crossover temperature, so that the radiation heat transfer may become a dominant mechanism of the flame propagation. In the case of non-uniform distribution of particles, the temperature gradient formed due to the radiation preheating can initiate either deflagration or detonation ahead of the original flame via the Zel'dovich's gradient mechanism. Th...

  19. Means for the focusing and acceleration of parallel beams of charged particles. [Patent application

    DOE Patents [OSTI]

    Maschke, A.W.

    1980-09-23

    Apparatus for focusing beams of charged particles comprising planar arrays of electrostatic quadrupoles. The array may be assembled from a single component which comprises a support plate containing uniform rows of poles. Each pole is separated by a hole through the plate designed to pass a beam. Two such plates may be positioned with their poles intermeshed to form a plurality of quadrupoles.

  20. Means for the focusing and acceleration of parallel beams of charged particles

    DOE Patents [OSTI]

    Maschke, Alfred W. (East Moriches, NY)

    1982-09-21

    Apparatus for focusing beams of charged particles comprising planar arrays of electrostatic quadrupoles. The array may be assembled from a single component which comprises a support plate containing uniform rows of poles. Each pole is separated by a hole through the plate designed to pass a beam. Two such plates may be positioned with their poles intermeshed to form a plurality of quadrupoles.

  1. Study of high-energy particle acceleration in Tycho with gamma-ray observations

    E-Print Network [OSTI]

    Park, Nahee

    2015-01-01

    Gamma-ray emission from supernova remnants (SNRs) can provide a unique window to observe the cosmic-ray acceleration believed to take place in these objects. Tycho is an especially good target for investigating hadronic cosmic-ray acceleration and interactions because it is a young type Ia SNR that is well studied in other wavelengths, and it is located in a relatively clean environment. Several different theoretical models have been advanced to explain the broadband spectral energy emission of Tycho from radio to the gamma-ray emission detected by the Fermi-LAT in the GeV and by VERITAS in the TeV. We will present an update on the high-energy gamma-ray studies of Tycho with $\\sim150$ hours of VERITAS and $\\sim77$ months of the Fermi-LAT observations, which represents about a factor of two increase in exposure over previously published data. VERITAS data also include exposure with an upgraded camera, which made it possible to extend the TeV measurements toward lower energy, thanks to its improved low energy s...

  2. FFAG ACCELERATOR PROTON DRIVER FOR NEUTRINO FACTORY.

    SciTech Connect (OSTI)

    RUGGIERO, A.

    2005-06-21

    This paper is the summary of a conceptual study of a Proton Driver for Neutrino Factory based on the use of a Fixed-Field Alternating-Gradient (FFAG) Accelerator. The required proton energy range for an optimum neutrino production is 5 to 12 GeV. This can be accomplished with a group of three concentric rings each with 807 m circumference [1]. FFAG Accelerators [2] have the capability to accelerate charged particles over a large momentum range ({+-}30-50%) and the feature of constant bending and focusing fields. Particles can be accelerated very fast at the rate given by the accelerating field of RF cavities placed in proper locations between magnets. The performance of FFAG accelerators is to be placed between that of Super-Conducting Linear Accelerators (SCL), with which they share the fast acceleration rate, and Rapid-Cycling Synchrotrons (RCS), as they allow the beam to re-circulate over fewer revolutions. Brookhaven National Laboratory is involved in the study of feasibility of FFAG Accelerators to accelerate intense beams of protons in the GeV energy range for a variety of applications the most important of which is the Upgrade of the Alternating Gradient Synchrotron (AGS) with a new FFAG injector [3] accelerating from 400 MeV to 1.5 GeV. The ring would be housed in the AGS tunnel and has henceforth a circumference of 807 m.

  3. COVER: Part of the drift-tube linear accelerator designed and built by Los Alamos National Laboratory for the Spallation Neutron Source at ORNL (see article on p.13). Photograph by Leroy N. Sanchez of LANL.

    E-Print Network [OSTI]

    #12;COVER: Part of the drift-tube linear accelerator designed and built by Los Alamos National, Brookhaven, Jefferson, and Los Alamos. No single laboratory possessed the resources needed to design

  4. The Real-Time Data Analysis and Decision System for Particle Flux Detection in the LHC Accelerator at CERN.

    E-Print Network [OSTI]

    Zamantzas, C; Dehning, B

    2006-01-01

    The superconducting Large Hadron Collider (LHC) under construction at the European Organisation for Nuclear Research (CERN) is an accelerator unprecedented in terms of beam energy, particle production rate and also in the potential of self-destruction. Its operation requires a large variety of instrumentation, not only for the control of the beams, but also for the protection of the complex hardware systems. The Beam Loss Monitoring (BLM) system has to prevent the superconducting magnets from becoming normal conducting and protect the machine components against damages making it one of the most critical elements for the protection of the LHC. For its operation, the system requires 3600 detectors to be placed at various locations around the 27 km ring. The measurement system is sub-divided to the tunnel electronics, which are responsible for acquiring, digitising and transmitting the data, and the surface electronics, which receive the data via 2 km optical data links, process, analyze, store and issue warning...

  5. Linear dynamics of charged particles in the main lattices of storage rings

    E-Print Network [OSTI]

    Shishanin, Oleg

    2015-01-01

    To study the characteristics of synchrotron radiation in magnetic fields of accelerators first the author was necessary to obtain a continuous solutions of Hill's equation. For this purpose the gradient or the components of magnetic field were developed in a series. The same procedure is followed now in the case of storage rings. This approach proved to be interesting not only from the point of view of describing the motion of partiles in ordinary three-dimensional space but also in the fact that we get new differential equations. This brief review can be regarded as an introduction to the proposed method. The next step may be to add nonlinearities. This would be the best approximation to the determination of betatron oscillations in the existing accelerators.

  6. SU-E-T-226: Junction Free Craniospinal Irradiation in Linear Accelerator Using Volumetric Modulated Arc Therapy : A Novel Technique Using Dose Tapering

    SciTech Connect (OSTI)

    Sarkar, B; Roy, S; Paul, S; Munshi, A; Roy, Shilpi; Jassal, K; Ganesh, T; Mohanti, BK

    2014-06-01

    Purpose: Spatially separated fields are required for craniospinal irradiation due to field size limitation in linear accelerator. Field junction shits are conventionally done to avoid hot or cold spots. Our study was aimed to demonstrate the feasibility of junction free irradiation plan of craniospinal irradiation (CSI) for Meduloblastoma cases treated in linear accelerator using Volumetric modulated arc therapy (VMAT) technique. Methods: VMAT was planned using multiple isocenters in Monaco V 3.3.0 and delivered in Elekta Synergy linear accelerator. A full arc brain and 40° posterior arc spine fields were planned using two isocentre for short (<1.3 meter height ) and 3 isocentres for taller patients. Unrestricted jaw movement was used in superior-inferior direction. Prescribed dose to PTV was achieved by partial contribution from adjacent beams. A very low dose gradient was generated to taper the isodoses over a long length (>10 cm) at the conventional field junction. Results: In this primary study five patients were planned and three patients were delivered using this novel technique. As the dose contribution from the adjacent beams were varied (gradient) to create a complete dose distribution, therefore there is no specific junction exists in the plan. The junction were extended from 10–14 cm depending on treatment plan. Dose gradient were 9.6±2.3% per cm for brain and 7.9±1.7 % per cm for spine field respectively. Dose delivery error due to positional inaccuracy was calculated for brain and spine field for ±1mm, ±2mm, ±3mm and ±5 mm were 1%–0.8%, 2%–1.6%, 2.8%–2.4% and 4.3%–4% respectively. Conclusion: Dose tapering in junction free CSI do not require a junction shift. Therefore daily imaging for all the field is also not essential. Due to inverse planning dose to organ at risk like thyroid kidney, heart and testis can be reduced significantly. VMAT gives a quicker delivery than Step and shoot or dynamic IMRT.

  7. Design Study of Beam Dynamics Issues for 1 TeV Next Linear Collider Based on Relativistic-Klystron Two-Beam-Accelerators

    E-Print Network [OSTI]

    Li, H.

    2008-01-01

    Yu, S. S. , "Relativistic Klystron Two-Beam Accelerator,"Consideration of Relativistic Klystron Two-Beam AcceleratorStudy of the Relativistic Klystron Two-Beam Accelerator

  8. A Chandra view of non-thermal emission in the northwestern region of supernova remnant RCW 86: Particle acceleration and magnetic fields

    SciTech Connect (OSTI)

    Castro, Daniel; Lopez, Laura A.; Figueroa-Feliciano, Enectali [MIT-Kavli Center for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Slane, Patrick O.; Yamaguchi, Hiroya [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ramirez-Ruiz, Enrico [Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95060 (United States)

    2013-12-10

    The shocks of supernova remnants are believed to accelerate particles to cosmic ray (CR) energies. The amplification of the magnetic field due to CRs propagating in the shock region is expected to have an impact on both the emission from the accelerated particle population as well as the acceleration process itself. Using a 95 ks observation with the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray Observatory, we map and characterize the synchrotron emitting material in the northwest region of RCW 86. We model spectra from several different regions, both filamentary and diffuse, where emission appears to be dominated by synchrotron radiation. The fine spatial resolution of Chandra allows us to obtain accurate emission profiles across three different non-thermal rims in this region. The narrow width (l ? 10''-30'') of these filaments constrains the minimum magnetic field strength at the post-shock region to approximately 80 ?G.

  9. Diffusive Acceleration of Ions at Interplanetary Shocks

    E-Print Network [OSTI]

    Matthew G. Baring; Errol J. Summerlin

    2005-06-08

    Heliospheric shocks are excellent systems for testing theories of particle acceleration in their environs. These generally fall into two classes: (1) interplanetary shocks that are linear in their ion acceleration characteristics, with the non-thermal ions serving as test particles, and (2) non-linear systems such as the Earth's bow shock and the solar wind termination shock, where the accelerated ions strongly influence the magnetohydrodynamic structure of the shock. This paper explores the modelling of diffusive acceleration at a particular interplanetary shock, with an emphasis on explaining in situ measurements of ion distribution functions. The observational data for this event was acquired on day 292 of 1991 by the Ulysses mission. The modeling is performed using a well-known kinetic Monte Carlo simulation, which has yielded good agreement with observations at several heliospheric shocks, as have other theoretical techniques, namely hybrid plasma simulations, and numerical solution of the diffusion-convection equation. In this theory/data comparison, it is demonstrated that diffusive acceleration theory can, to first order, successfully account for both the proton distribution data near the shock, and the observation of energetic protons farther upstream of this interplanetary shock than lower energy pick-up protons, using a single turbulence parameter. The principal conclusion is that diffusive acceleration of inflowing upstream ions can model this pick-up ion-rich event without the invoking any seed pre-acceleration mechanism, though this investigation does not rule out the action of such pre-acceleration.

  10. A Systems Study of an RF Power Source for a 1 TeV Next Linear Collider Based Upon the Relativistic-Klystron Two-Beam Accelerator

    E-Print Network [OSTI]

    Yu, S.

    2008-01-01

    Study of the Relativistic Klystron Two-Beam AcceleratorYu, S. S. , "Relativistic Klystron Two-Beam Accelerator,"S. , et al. , "Relativistic Klystron Two-Beam Accelerator As

  11. Reinventing the Accelerator for the High Energy Frontier

    ScienceCinema (OSTI)

    Rosenzweig, James [UCLA, Los Angeles, California, United States

    2009-09-01

    The history of discovery in high-energy physics has been intimately connected with progress in methods of accelerating particles for the past 75 years. This remains true today, as the post-LHC era in particle physics will require significant innovation and investment in a superconducting linear collider. The choice of the linear collider as the next-generation discovery machine, and the selection of superconducting technology has rather suddenly thrown promising competing techniques -- such as very large hadron colliders, muon colliders, and high-field, high frequency linear colliders -- into the background. We discuss the state of such conventional options, and the likelihood of their eventual success. We then follow with a much longer view: a survey of a new, burgeoning frontier in high energy accelerators, where intense lasers, charged particle beams, and plasmas are all combined in a cross-disciplinary effort to reinvent the accelerator from its fundamental principles on up.

  12. Beam-driven acceleration in ultra-dense plasma media

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

    Shin, Young-Min

    2014-09-15

    Accelerating parameters of beam-driven wakefield acceleration in an extremely dense plasma column has been analyzed with the dynamic framed particle-in-cell plasma simulator, and compared with analytic calculations. In the model, a witness beam undergoes a TeV/m scale alternating potential gradient excited by a micro-bunched drive beam in a 1025 m-3 and 1.6 x 1028 m-3 plasma column. The acceleration gradient, energy gain, and transformer ratio have been extensively studied in quasi-linear, linear-, and blowout-regimes. The simulation analysis indicated that in the beam-driven acceleration system a hollow plasma channel offers 20 % higher acceleration gradient by enlarging the channel radius (r)more »from 0.2 ?p to 0.6 ?p in a blowout regime. This paper suggests a feasibility of TeV/m scale acceleration with a hollow crystalline structure (e.g. nanotubes) of high electron plasma density.« less

  13. Beam generation and planar imaging at energies below 2.40 MeV with carbon and aluminum linear accelerator targets

    SciTech Connect (OSTI)

    Parsons, David; Robar, James L.

    2012-07-15

    Purpose: Recent work has demonstrated improvement of image quality with low-Z linear accelerator targets and energies as low as 3.5 MV. In this paper, the authors lower the incident electron beam energy between 1.90 and 2.35 MeV and assess the improvement of megavoltage planar image quality with the use of carbon and aluminum linear accelerator targets. Methods: The bending magnet shunt current was adjusted in a Varian linear accelerator to allow selection of mean electron energy between 1.90 and 2.35 MeV. Linac set points were altered to increase beam current to allow experimental imaging in a practical time frame. Electron energy was determined through comparison of measured and Monte Carlo modeled depth dose curves. Planar image CNR and spatial resolution measurements were performed to quantify the improvement of image quality. Magnitudes of improvement are explained with reference to Monte Carlo generated energy spectra. Results: After modifications to the linac, beam current was increased by a factor greater than four and incident electron energy was determined to have an adjustable range from 1.90 MeV to 2.35 MeV. CNR of cortical bone was increased by a factor ranging from 6.2 to 7.4 and 3.7 to 4.3 for thin and thick phantoms, respectively, compared to a 6 MV therapeutic beam for both aluminum and carbon targets. Spatial resolution was degraded slightly, with a relative change of 3% and 10% at 0.20 lp/mm and 0.40 lp/mm, respectively, when reducing energy from 2.35 to 1.90 MV. The percentage of diagnostic x-rays for the beams examined here, ranges from 46% to 54%.Conclusion: It is possible to produce a large fraction of diagnostic energy x-rays by lowering the beam energy below 2.35 MV. By lowering the beam energy to 1.90 MV or 2.35 MV, CNR improves by factors ranging from 3.7 to 7.4 compared to a 6 MV therapy beam, with only a slight degradation of spatial resolution when lowering the energy from 2.35 MV to 1.90 MV.

  14. Dynamical mean-field theory and weakly non-linear analysis for the phase separation of active Brownian particles

    E-Print Network [OSTI]

    Thomas Speck; Andreas M. Menzel; Julian Bialké; Hartmut Löwen

    2015-03-29

    Recently, we have derived an effective Cahn-Hilliard equation for the phase separation dynamics of active Brownian particles by performing a weakly non-linear analysis of the effective hydrodynamic equations for density and polarization [Phys. Rev. Lett. 112, 218304 (2014)]. Here we develop and explore this strategy in more detail and show explicitly how to get to such a large-scale, mean-field description starting from the microscopic dynamics. The effective free energy emerging from this approach has the form of a conventional Ginzburg-Landau function. On the coarsest scale, our results thus agree with the mapping of active phase separation onto that of passive fluids with attractive interactions through a global effective free energy (mobility-induced phase transition). Particular attention is paid to the square-gradient term necessary for the dynamics. We finally discuss results from numerical simulations corroborating the analytical results.

  15. Mean first passage times for bond formation for a Brownian particle in linear shear flow above a wall

    E-Print Network [OSTI]

    C. Korn; U. S. Schwarz

    2007-07-16

    Motivated by cell adhesion in hydrodynamic flow, here we study bond formation between a spherical Brownian particle in linear shear flow carrying receptors for ligands covering the boundary wall. We derive the appropriate Langevin equation which includes multiplicative noise due to position-dependent mobility functions resulting from the Stokes equation. We present a numerical scheme which allows to simulate it with high accuracy for all model parameters, including shear rate and three parameters describing receptor geometry (distance, size and height of the receptor patches). In the case of homogeneous coating, the mean first passage time problem can be solved exactly. In the case of position-resolved receptor-ligand binding, we identify different scaling regimes and discuss their biological relevance.

  16. European Particle Accelerator Conference -Rome, Italy -June 7-12, 1988 DEVELOPMENT OFA HIGH BRIGHTNESS ELECTRON GUN FOR THE ACCELERATOR TEST FACILITY AT

    E-Print Network [OSTI]

    McDonald, Kirk

    BRIGHTNESS ELECTRON GUN FOR THE ACCELERATOR TEST FACILITY AT BROOKHAVEN NATIONAL LABORATORY* K. Batchelor, HDonald Princeton University At innBNL--41767 DE89 002179 Abstract An electron gun utilizing aradio frequency on the design of (he electron gun which will provide r.f. bunches of upto 101 electrons synchronized

  17. Intensity-modulated radiation therapy (IMRT) dosimetry of the head and neck: A comparison of treatment plans using linear accelerator-based IMRT and helical tomotherapy

    SciTech Connect (OSTI)

    Sheng Ke [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)]. E-mail: ks2mc@virginia.edu; Molloy, Janelle A. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Read, Paul W. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)

    2006-07-01

    Purpose: To date, most intensity-modulated radiation therapy (IMRT) delivery has occurred using linear accelerators (linacs), although helical tomotherapy has become commercially available. To quantify the dosimetric difference, we compared linac-based and helical tomotherapy-based treatment plans for IMRT of the oropharynx. Methods and Materials: We compared the dosimetry findings of 10 patients who had oropharyngeal carcinoma. Five patients each had cancers in the base of the tongue and tonsil. Each plan was independently optimized using either the CORVUS planning system (Nomos Corporation, Sewickly, PA), commissioned for a Varian 2300 CD linear accelerator (Varian Medical Systems, Palo Alto, CA) with 1-cm multileaf collimator leaves, or helical tomotherapy. The resulting treatment plans were evaluated by comparing the dose-volume histograms, equivalent uniform dose (EUD), dose uniformity, and normal tissue complication probabilities. Results: Helical tomotherapy plans showed improvement of critical structure avoidance and target dose uniformity for all patients. The average equivalent uniform dose reduction for organs at risk (OARs) surrounding the base of tongue and the tonsil were 17.4% and 27.14% respectively. An 80% reduction in normal tissue complication probabilities for the parotid glands was observed in the tomotherapy plans relative to the linac-based plans. The standard deviation of the planning target volume dose was reduced by 71%. In our clinic, we use the combined dose-volume histograms for each class of plans as a reference goal for helical tomotherapy treatment planning optimization. Conclusions: Helical tomotherapy provides improved dose homogeneity and normal structure dose compared with linac-based IMRT in the treatment of oropharyngeal carcinoma resulting in a reduced risk for complications from focal hotspots within the planning target volume and for the adjacent parotid glands.

  18. Feasibility of producing a short, high energy s-band linear accelerator using a klystron power source

    SciTech Connect (OSTI)

    Baillie, Devin [Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Aubin, J. St. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Fallone, B. G. [Department of Physics, University of Alberta, 11322-89 Avenue, Edmonton, Alberta T6G 2G7 (Canada); Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Steciw, S. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)

    2013-04-15

    Purpose: To use a finite-element method (FEM) model to study the feasibility of producing a short s-band (2.9985 GHz) waveguide capable of producing x-rays energies up to 10 MV, for applications in a linac-MR, as well as conventional radiotherapy. Methods: An existing waveguide FEM model developed by the authors' group is used to simulate replacing the magnetron power source with a klystron. Peak fields within the waveguide are compared with a published experimental threshold for electric breakdown. The RF fields in the first accelerating cavity are scaled, approximating the effect of modifications to the first coupling cavity. Electron trajectories are calculated within the RF fields, and the energy spectrum, beam current, and focal spot of the electron beam are analyzed. One electron spectrum is selected for Monte Carlo simulations and the resulting PDD compared to measurement. Results: When the first cavity fields are scaled by a factor of 0.475, the peak magnitude of the electric fields within the waveguide are calculated to be 223.1 MV/m, 29% lower than the published threshold for breakdown at this operating frequency. Maximum electron energy increased from 6.2 to 10.4 MeV, and beam current increased from 134 to 170 mA. The focal spot FWHM is decreased slightly from 0.07 to 0.05 mm, and the width of the energy spectrum increased slightly from 0.44 to 0.70 MeV. Monte Carlo results show d{sub max} is at 2.15 cm for a 10 Multiplication-Sign 10 cm{sup 2} field, compared with 2.3 cm for a Varian 10 MV linac, while the penumbral widths are 4.8 and 5.6 mm, respectively. Conclusions: The authors' simulation results show that a short, high-energy, s-band accelerator is feasible and electric breakdown is not expected to interfere with operation at these field strengths. With minor modifications to the first coupling cavity, all electron beam parameters are improved.

  19. Fermilab | Science | Particle Accelerators

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photo feature photo feature

  20. Laser Wakefield Particle Acceleration

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesse Bergkamp Graduate studentScienceLaboratoryandBryanoutreach LaserLaserLaser

  1. Relativistic-Klystron Two-Beam Accelerator as a Power Source for a 1 Tev Next Linear Collider - A Systems Study

    E-Print Network [OSTI]

    Yu, S.

    2008-01-01

    Study of the Relativistic Klystron Two- Beam AcceleratorProceedings Relativistic-Klystron Two-Beam-Accelerator as a76SF00098 RELATIVISTIC- KLYSTRON TWO-REAM-ACCELERATOR AS A

  2. Acceleration and stability of a high-current ion beam in induction fields

    SciTech Connect (OSTI)

    Karas', V. I.; Manuilenko, O. V.; Tarakanov, V. P.; Federovskaya, O. V.

    2013-03-15

    A one-dimensional nonlinear analytic theory of the filamentation instability of a high-current ion beam is formulated. The results of 2.5-dimensional numerical particle-in-cell simulations of acceleration and stability of an annular compensated ion beam (CIB) in a linear induction particle accelerator are presented. It is shown that additional transverse injection of electron beams in magnetically insulated gaps (cusps) improves the quality of the ion-beam distribution function and provides uniform beam acceleration along the accelerator. The CIB filamentation instability in both the presence and the absence of an external magnetic field is considered.

  3. From Autos to Accelerators

    Office of Energy Efficiency and Renewable Energy (EERE)

    In a town haunted by the remains of fallen automobile plants, some companies are hiring workers to put their car-manufacturing skills toward building particle accelerators.

  4. Intraoperative Radiation Therapy in Early Breast Cancer Using a Linear Accelerator Outside of the Operative Suite: An “Image-Guided” Approach

    SciTech Connect (OSTI)

    Hanna, Samir Abdallah; Simões Dornellas de Barros, Alfredo Carlos; Martins de Andrade, Felipe Eduardo; Barbosa Bevilacqua, Jose Luiz; Morales Piato, José Roberto; Lopes Pelosi, Edilson; Martella, Eduardo; Fernandes da Silva, João Luis; Andrade Carvalho, Heloisa de

    2014-08-01

    Purpose: To present local control, complications, and cosmetic outcomes of intraoperative radiation therapy (IORT) for early breast cancer, as well as technical aspects related to the use of a nondedicated linear accelerator. Methods and Materials: This prospective trial began in May of 2004. Eligibility criteria were biopsy-proven breast-infiltrating ductal carcinoma, age >40 years, tumor <3 cm, and cN0. Exclusion criteria were in situ or lobular types, multicentricity, skin invasion, any contraindication for surgery and/or radiation therapy, sentinel lymph node involvement, metastasis, or another malignancy. Patients underwent classic quadrantectomy with intraoperative sentinel lymph node and margins evaluation. If both free, the patient was transferred from operative suite to linear accelerator room, and IORT was delivered (21 Gy). Primary endpoint: local recurrence (LR); secondary endpoints: toxicities and aesthetics. Quality assurance involved using a customized shield for chest wall protection, applying procedures to minimize infection caused by patient transportation, and using portal films to check collimator-shield alignment. Results: A total of 152 patients were included, with at least 1 year follow-up. Median age (range) was 58.3 (40-85.4) years, and median follow-up time was 50.7 (12-110.5) months. The likelihood of 5-year local recurrence was 3.7%. There were 3 deaths, 2 of which were cancer related. The Kaplan-Meier 5-year actuarial estimates of overall, disease-free, and local recurrence-free survivals were 97.8%, 92.5%, and 96.3%, respectively. The overall incidences of acute and late toxicities were 12.5% and 29.6%, respectively. Excellent, good, fair, and bad cosmetic results were observed in 76.9%, 15.8%, 4.3%, and 2.8% of patients, respectively. Most treatments were performed with a 5-cm collimator, and in 39.8% of the patients the electron-beam energy used was ?12 MeV. All patients underwent portal film evaluation, and the shielding was repositioned in 39.9% of cases. No infection or anesthesia complications were observed. Conclusions: Local control with IORT was adequate, with low complication rates and good cosmetic outcomes. More than one-third of patients benefited from the “image-guidance” approach, and almost 40% benefited from the option of higher electron beam energies.

  5. LASER-PLASMA-ACCELERATOR-BASED GAMMA GAMMA COLLIDERS

    E-Print Network [OSTI]

    Schroeder, C. B.

    2010-01-01

    LASER-PLASMA-ACCELERATOR-BASED ?? COLLIDERS ? C. B.linear col- lider based on laser-plasma-accelerators arediscussed, and a laser-plasma-accelerator-based gamma-

  6. PUBLISHED ONLINE: 10 JANUARY 2012 | DOI: 10.1038/NPHYS2179 Acceleration in the linear non-scaling fixed-field

    E-Print Network [OSTI]

    Keil, Eberhard

    , and for accelerator-driven reactor systems9 . Several scaling proton FFAGs have now been constructed9

  7. Field calculations, single-particle tracking, and beam dynamics with space charge in the electron lens for the Fermilab Integrable Optics Test Accelerator

    SciTech Connect (OSTI)

    Noll, Daniel; Stancari, Giulio

    2015-11-17

    An electron lens is planned for the Fermilab Integrable Optics Test Accelerator as a nonlinear element for integrable dynamics, as an electron cooler, and as an electron trap to study space-charge compensation in rings. We present the main design principles and constraints for nonlinear integrable optics. A magnetic configuration of the solenoids and of the toroidal section is laid out. Singleparticle tracking is used to optimize the electron path. Electron beam dynamics at high intensity is calculated with a particle-in-cell code to estimate current limits, profile distortions, and the effects on the circulating beam. In the conclusions, we summarize the main findings and list directions for further work.

  8. Safety training and safe operating procedures written for PBFA (Particle Beam Fusion Accelerator) II and applicable to other pulsed power facilities

    SciTech Connect (OSTI)

    Donovan, G.L.; Goldstein, S.A.

    1986-12-01

    To ensure that work in advancing pulsed power technology is performed with an acceptably low risk, pulsed power research facilities at Sandia National Laboratories must satisfy general safety guidelines established by the Department of Energy, policies and formats of the Environment, Safety, and Health (ES and H) Department, and detailed procedures formulated by the Pulsed Power Sciences Directorate. The approach to safety training and to writing safe operating procedures, and the procedures presented here are specific to the Particle Beam Fusion Accelerator II (PBFA II) Facility but are applicable as guidelines to other research and development facilities which have similar hazards.

  9. Compact accelerator

    DOE Patents [OSTI]

    Caporaso, George J. (Livermore, CA); Sampayan, Stephen E. (Manteca, CA); Kirbie, Hugh C. (Los Alamos, NM)

    2007-02-06

    A compact linear accelerator having at least one strip-shaped Blumlein module which guides a propagating wavefront between first and second ends and controls the output pulse at the second end. Each Blumlein module has first, second, and third planar conductor strips, with a first dielectric strip between the first and second conductor strips, and a second dielectric strip between the second and third conductor strips. Additionally, the compact linear accelerator includes a high voltage power supply connected to charge the second conductor strip to a high potential, and a switch for switching the high potential in the second conductor strip to at least one of the first and third conductor strips so as to initiate a propagating reverse polarity wavefront(s) in the corresponding dielectric strip(s).

  10. Power Converters for Accelerators

    E-Print Network [OSTI]

    Visintini, R

    2015-01-01

    Particle accelerators use a great variety of power converters for energizing their sub-systems; while the total number of power converters usually depends on the size of the accelerator or combination of accelerators (including the experimental setup), the characteristics of power converters depend on their loads and on the particle physics requirements: this paper aims to provide an overview of the magnet power converters in use in several facilities worldwide.

  11. Accelerated Quantum Dynamics

    E-Print Network [OSTI]

    Lynch, Morgan H

    2015-01-01

    In this paper we establish a formalism for the computation of observables due to acceleration-induced particle physics processes. General expressions for the transition rate, multiplicity, power, spectra, and displacement law of particles undergoing time-dependent acceleration and transitioning into a final state of arbitrary particle number are obtained. The transition rate, power, and spectra are characterised by unique polynomials of multiplicity and thermal distributions of both bosonic and fermionic statistics. The acceleration dependent multiplicity is computed in terms of the branching fractions of the associated inertial processes. The displacement law of the spectra predicts the energy of the emitted particles are directly proportional to the accelerated temperature. These results extend our understanding of particle physics into the high acceleration sector.

  12. Plasmoid Ejections and Loop Contractions in an Eruptive M7.7 Solar Flare: Evidence of Particle Acceleration and Heating in Magnetic Reconnection Outflows

    E-Print Network [OSTI]

    Liu, Wei; Petrosian, Vahe'

    2013-01-01

    Where particle acceleration and plasma heating take place in relation to magnetic reconnection is a fundamental question for solar flares. We report analysis of an M7.7 flare on 2012 July 19 observed by SDO/AIA and RHESSI. Bi-directional outflows in forms of plasmoid ejections and contracting cusp-shaped loops originate between an erupting flux rope and underlying flare loops at speeds of typically 200-300 km/s up to 1050 km/s. These outflows are associated with spatially separated double coronal X-ray sources with centroid separation decreasing with energy. The highest temperature is located near the nonthermal X-ray loop-top source well below the original heights of contracting cusps near the inferred reconnection site. These observations suggest that the primary loci of particle acceleration and plasma heating are in the reconnection outflow regions, rather than the reconnection site itself. In addition, there is an initial ascent of the X-ray and EUV loop-top source prior to its recently recognized descen...

  13. A magnetohydrodynamic model of the M87 jet. II. Self-consistent quad-shock jet model for optical relativistic motions and particle acceleration

    SciTech Connect (OSTI)

    Nakamura, Masanori

    2014-04-20

    We describe a new paradigm for understanding both relativistic motions and particle acceleration in the M87 jet: a magnetically dominated relativistic flow that naturally produces four relativistic magnetohydrodynamic (MHD) shocks (forward/reverse fast and slow modes). We apply this model to a set of optical super- and subluminal motions discovered by Biretta and coworkers with the Hubble Space Telescope during 1994-1998. The model concept consists of ejection of a single relativistic Poynting jet, which possesses a coherent helical (poloidal + toroidal) magnetic component, at the remarkably flaring point HST-1. We are able to reproduce quantitatively proper motions of components seen in the optical observations of HST-1 with the same model we used previously to describe similar features in radio very long baseline interferometry observations in 2005-2006. This indicates that the quad relativistic MHD shock model can be applied generally to recurring pairs of super/subluminal knots ejected from the upstream edge of the HST-1 complex as observed from radio to optical wavelengths, with forward/reverse fast-mode MHD shocks then responsible for observed moving features. Moreover, we identify such intrinsic properties as the shock compression ratio, degree of magnetization, and magnetic obliquity and show that they are suitable to mediate diffusive shock acceleration of relativistic particles via the first-order Fermi process. We suggest that relativistic MHD shocks in Poynting-flux-dominated helical jets may play a role in explaining observed emission and proper motions in many active galactic nuclei.

  14. Magneto-optical granulometry: on the determination of the statistics of magnetically induced particle chains in concentrated ferrofluids from linear dichroism experiments

    E-Print Network [OSTI]

    V. Socoliuc; L. B. Popescu

    2014-10-09

    An analytical theoretical model for the influence of the magnetically induced nanoparticle chaining on the linear dichroism in ferrofluids was developed. The model is based on a statistical theory for magnetic nanoparticle chaining in ferrofluids. Together with appropriate experimental approach and data processing strategy, the model grounds a magneto-optical granulometry method able to determine the magnetic field dependence of the statistics of magnetically induced particle chains in concentrated ferrofluids.

  15. Accelerators for high energy physics research

    SciTech Connect (OSTI)

    Chao, A.

    1995-12-01

    A brief survey of particle accelerators as research tools for high energy physics is given. The survey includes existing accelerators, as well as those envisioned for the future.

  16. Dielectric-wall linear accelerator with a high voltage fast rise time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators

    DOE Patents [OSTI]

    Caporaso, G.J.; Sampayan, S.E.; Kirbie, H.C.

    1998-10-13

    A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 12 figs.

  17. Dielectric-wall linear accelerator with a high voltage fast rise time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators

    DOE Patents [OSTI]

    Caporaso, George J. (Livermore, CA); Sampayan, Stephen E. (Manteca, CA); Kirbie, Hugh C. (Dublin, CA)

    1998-01-01

    A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.

  18. Particle Physics Booklet 2008

    E-Print Network [OSTI]

    et al., C. Amsler

    2008-01-01

    212 25. Accelerator physics of colliders ? 26. High-energythe full Review. PARTICLE PHYSICS BOOKLET TABLE OF CONTENTSrev. ) Summary Tables of Particle Physics Gauge and Higgs

  19. Klystron switching power supplies for the Internation Linear Collider

    SciTech Connect (OSTI)

    Fraioli, Andrea; /Cassino U. /INFN, Pisa

    2009-12-01

    The International Linear Collider is a majestic High Energy Physics particle accelerator that will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. ILC will complement the Large Hadron Collider (LHC), a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, by producing electron-positron collisions at center of mass energy of about 500 GeV. In particular, the subject of this dissertation is the R&D for a solid state Marx Modulator and relative switching power supply for the International Linear Collider Main LINAC Radio Frequency stations.

  20. Universal statistics of density of inertial particles sedimenting in turbulence

    E-Print Network [OSTI]

    Itzhak Fouxon; Yongnam Park; Roei Harduf; Changhoon Lee

    2014-10-30

    We solve the problem of spatial distribution of inertial particles that sediment in Navier-Stokes turbulence with small ratio $Fr$ of acceleration of fluid particles to acceleration of gravity $g$. The particles are driven by linear drag and have arbitrary inertia. We demonstrate that independently of the particles' size or density the particles distribute over fractal set with log-normal statistics determined completely by the Kaplan-Yorke dimension $D_{KY}$. When inertia is not small $D_{KY}$ is proportional to the ratio of integral of spectrum of turbulence multiplied by wave-number and $g$. This ratio is independent of properties of particles so that the particles concentrate on fractal with universal, particles-independent statistics. We find Lyapunov exponents and confirm predictions numerically. The considered case includes typical situation of water droplets in clouds.

  1. A novel adaptive time stepping variant of the Boris–Buneman integrator for the simulation of particle accelerators with space charge

    SciTech Connect (OSTI)

    Toggweiler, Matthias; Adelmann, Andreas; Arbenz, Peter; Yang, Jianjun

    2014-09-15

    We show that adaptive time stepping in particle accelerator simulation is an enhancement for certain problems. The new algorithm has been implemented in the OPAL (Object Oriented Parallel Accelerator Library) framework. The idea is to adjust the frequency of costly self-field calculations, which are needed to model Coulomb interaction (space charge) effects. In analogy to a Kepler orbit simulation that requires a higher time step resolution at the close encounter, we propose to choose the time step based on the magnitude of the space charge forces. Inspired by geometric integration techniques, our algorithm chooses the time step proportional to a function of the current phase space state instead of calculating a local error estimate like a conventional adaptive procedure. Building on recent work, a more profound argument is given on how exactly the time step should be chosen. An intermediate algorithm, initially built to allow a clearer analysis by introducing separate time steps for external field and self-field integration, turned out to be useful by its own, for a large class of problems.

  2. COMPASS, the COMmunity Petascale project for Accelerator Science and Simulation, a board computational accelerator physics initiative

    E-Print Network [OSTI]

    Cary, J.R.

    2008-01-01

    computational accelerator physics initiative † J R Carycomputational accelerator physics initiative J R Cary 1,9 ,colliders for particle physics and nuclear science and light

  3. Fermilab | Science | Particle Accelerators | Fermilab's Accelerator Complex

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photo feature photoFermilab's

  4. Fermilab | Science | Particle Accelerators | Leading Accelerator Technology

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photo feature photoFermilab'sLHC

  5. The International Linear Collider

    E-Print Network [OSTI]

    Karsten Buesser

    2013-06-13

    The International Linear Collider (ILC) is a proposed electron-positron collider for the centre-of-mass energy range of 200 to 500 GeV and with upgrade options towards 1 TeV. The ILC would be the ideal tool to explore with high precision the properties of the new Higgs-like particle that has recently been discovered at the LHC with a mass of around 125 GeV. The ILC accelerator design is based on the mature superconducting technology that has been developed in the TESLA collaboration and that is currently being used for the European XFEL. The exploitation of the huge physics potential of the ILC is a challenge for the design of the ILC detectors.

  6. Physics at the International Linear Collider

    E-Print Network [OSTI]

    J. List

    2006-05-18

    The International Linear Collider (ILC) is the next large project in accelerator based particle physics. It is complementary to the LHC in many aspects. Measurements from both machines together will finally shed light onto the known deficiencies of the Standard Model of particle physics and allow to unveil a possible underlying more fundamental theory. Here, the possibilities of the ILC will be discussed with special emphasis on the Higgs sector and on topics with a strong connection to cosmological questions like extra dimensions or dark matter candidates.

  7. Leaky Fermi accelerators

    E-Print Network [OSTI]

    Shah, Kushal; Rom-Kedar, Vered; Turaev, Dmitry

    2015-01-01

    A Fermi accelerator is a billiard with oscillating walls. A leaky accelerator interacts with an environment of an ideal gas at equilibrium by exchange of particles through a small hole on its boundary. Such interaction may heat the gas: we estimate the net energy flow through the hole under the assumption that the particles inside the billiard do not collide with each other and remain in the accelerator for sufficiently long time. The heat production is found to depend strongly on the type of the Fermi accelerator. An ergodic accelerator, i.e. one which has a single ergodic component, produces a weaker energy flow than a multi-component accelerator. Specifically, in the ergodic case the energy gain is independent of the hole size, whereas in the multi-component case the energy flow may be significantly increased by shrinking the hole size.

  8. Leaky Fermi accelerators

    E-Print Network [OSTI]

    Kushal Shah; Vassili Gelfreich; Vered Rom-Kedar; Dmitry Turaev

    2015-04-03

    A Fermi accelerator is a billiard with oscillating walls. A leaky accelerator interacts with an environment of an ideal gas at equilibrium by exchange of particles through a small hole on its boundary. Such interaction may heat the gas: we estimate the net energy flow through the hole under the assumption that the particles inside the billiard do not collide with each other and remain in the accelerator for sufficiently long time. The heat production is found to depend strongly on the type of the Fermi accelerator. An ergodic accelerator, i.e. one which has a single ergodic component, produces a weaker energy flow than a multi-component accelerator. Specifically, in the ergodic case the energy gain is independent of the hole size, whereas in the multi-component case the energy flow may be significantly increased by shrinking the hole size.

  9. The International Linear Collider

    E-Print Network [OSTI]

    Barish, Barry

    2013-01-01

    In this article, we describe the key features of the recently completed technical design for the International Linear Collider (ILC), a 200-500 GeV linear electron-positron collider (expandable to 1 TeV) that is based on 1.3 GHz superconducting radio-frequency (SCRF) technology. The machine parameters and detector characteristics have been chosen to complement the Large Hadron Collider physics, including the discovery of the Higgs boson, and to further exploit this new particle physics energy frontier with a precision instrument. The linear collider design is the result of nearly twenty years of R&D, resulting in a mature conceptual design for the ILC project that reflects an international consensus. We summarize the physics goals and capability of the ILC, the enabling R&D and resulting accelerator design, as well as the concepts for two complementary detectors. The ILC is technically ready to be proposed and built as a next generation lepton collider, perhaps to be built in stages beginning as a Hig...

  10. Mapping the particle acceleration in the cool core of the galaxy cluster RX J1720.1+2638

    SciTech Connect (OSTI)

    Giacintucci, S. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Markevitch, M. [Joint Space-Science Institute, University of Maryland, College Park, MD, 20742-2421 (United States); Brunetti, G.; Venturi, T. [INAF—Istituto di Radioastronomia, Via Gobetti 101, I-40129 Bologna (Italy); ZuHone, J. A. [Astrophysics Science Division, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Mazzotta, P.; Bourdin, H., E-mail: simona@astro.umd.edu [Dipartimento di Fisica, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Rome (Italy)

    2014-11-01

    We present new deep, high-resolution radio images of the diffuse minihalo in the cool core of the galaxy cluster RX J1720.1+2638. The images have been obtained with the Giant Metrewave Radio Telescope at 317, 617, and 1280 MHz and with the Very Large Array at 1.5, 4.9, and 8.4 GHz, with angular resolutions ranging from 1'' to 10''. This represents the best radio spectral and imaging data set for any minihalo. Most of the radio flux of the minihalo arises from a bright central component with a maximum radius of ?80 kpc. A fainter tail of emission extends out from the central component to form a spiral-shaped structure with a length of ?230 kpc, seen at frequencies 1.5 GHz and below. We find indication of a possible steepening of the total radio spectrum of the minihalo at high frequencies. Furthermore, a spectral index image shows that the spectrum of the diffuse emission steepens with increasing distance along the tail. A striking spatial correlation is observed between the minihalo emission and two cold fronts visible in the Chandra X-ray image of this cool core. These cold fronts confine the minihalo, as also seen in numerical simulations of minihalo formation by sloshing-induced turbulence. All these observations favor the hypothesis that the radio-emitting electrons in cluster cool cores are produced by turbulent re-acceleration.

  11. Challenges in Accelerator Beam Instrumentation

    SciTech Connect (OSTI)

    Wendt, M.

    2009-12-01

    The challenges in beam instrumentation and diagnostics for present and future particle accelerator projects are presented. A few examples for advanced hadron and lepton beam diagnostics are given.

  12. Lab Breakthrough: Fermilab Accelerator Technology

    Broader source: Energy.gov [DOE]

    Fermilab scientists developed techniques to retrofit some of the 30,000 particle accelerators in use around the world to make them more efficient and powerful.

  13. Accelerator on a Chip

    ScienceCinema (OSTI)

    England, Joel

    2014-07-16

    SLAC's Joel England explains how the same fabrication techniques used for silicon computer microchips allowed their team to create the new laser-driven particle accelerator chips. (SLAC Multimedia Communications)

  14. Breakthrough: Fermilab Accelerator Technology

    ScienceCinema (OSTI)

    None

    2014-08-12

    There are more than 30,000 particle accelerators in operation around the world. At Fermilab, scientists are collaborating with other laboratories and industry to optimize the manufacturing processes for a new type of powerful accelerator that uses superconducting niobium cavities. Experimenting with unique polishing materials, a Fermilab team has now developed an efficient and environmentally friendly way of creating cavities that can propel particles with more than 30 million volts per meter.

  15. Solving NonlinearSolving Nonlinear EigenproblemsEigenproblems inin Accelerator Cavity DesignAccelerator Cavity Design

    E-Print Network [OSTI]

    California at Davis, University of

    Light Source RF-gun Accelerating cavity for International Linear Collider Summary and Future work #12 Light Source RF-gun Accelerating cavity for International Linear Collider Summary and Future work #12;RF-gun Accelerating cavity for International Linear Collider Summary and Future work #12;Quadratric

  16. Experimental Particle Physics

    SciTech Connect (OSTI)

    Rosenfeld, Carl; Mishra, Sanjib R.; Petti, Roberto; Purohit, Milind V.

    2014-08-31

    The high energy physics group at the University of South Carolina, under the leadership of Profs. S.R. Mishra, R. Petti, M.V. Purohit, J.R. Wilson (co-PI's), and C. Rosenfeld (PI), engaged in studies in "Experimental Particle Physics." The group collaborated with similar groups at other universities and at national laboratories to conduct experimental studies of elementary particle properties. We utilized the particle accelerators at the Fermi National Accelerator Laboratory (Fermilab) in Illinois, the Stanford Linear Accelerator Center (SLAC) in California, and the European Center for Nuclear Research (CERN) in Switzerland. Mishra, Rosenfeld, and Petti worked predominantly on neutrino experiments. Experiments conducted in the last fifteen years that used cosmic rays and the core of the sun as a source of neutrinos showed conclusively that, contrary to the former conventional wisdom, the "flavor" of a neutrino is not immutable. A neutrino of flavor "e," "mu," or "tau," as determined from its provenance, may swap its identity with one of the other flavors -- in our jargon, they "oscillate." The oscillation phenomenon is extraordinarily difficult to study because neutrino interactions with our instruments are exceedingly rare -- they travel through the earth mostly unimpeded -- and because they must travel great distances before a substantial proportion have made the identity swap. Three of the experiments that we worked on, MINOS, NOvA, and LBNE utilize a beam of neutrinos from an accelerator at Fermilab to determine the parameters governing the oscillation. Two other experiments that we worked on, NOMAD and MIPP, provide measurements supportive of the oscillation experiments. Good measurements of the neutrino oscillation parameters may constitute a "low energy window" on related phenomena that are otherwise unobservable because they would occur only at energies way above the reach of conceivable accelerators. Purohit and Wilson participated in the BaBar experiment, which collected data at SLAC until 2008. They continued to analyze the voluminous BaBar data with an emphasis on precision tests of Quantum Chromodynamics and on properties of the "eta_B," a bottom quark paired in a meson with a strange quark. The ATLAS experiment became the principal research focus for Purohit. One of the world's largest pieces of scientific equipment, ATLAS observes particle collisions at the highest-energy particle accelerator ever built, the Large Hadron Collider (LHC) at CERN. Our efforts on ATLAS included participation in the commissioning, calibration, and installation of components called "CSCs". The unprecedented energy of 14 TeV enabled the ATLAS and CMS collaborations to declare discovery of the famous Higgs particle in 2012.

  17. The Brookhaven National Laboratory Accelerator Test Facility

    SciTech Connect (OSTI)

    Batchelor, K.

    1992-01-01

    The Brookhaven National Laboratory Accelerator Test Facility comprises a 50 MeV traveling wave electron linear accelerator utilizing a high gradient, photo-excited, raidofrequency electron gun as an injector and an experimental area for study of new acceleration methods or advanced radiation sources using free electron lasers. Early operation of the linear accelerator system including calculated and measured beam parameters are presented together with the experimental program for accelerator physics and free electron laser studies.

  18. The Brookhaven National Laboratory Accelerator Test Facility

    SciTech Connect (OSTI)

    Batchelor, K.

    1992-09-01

    The Brookhaven National Laboratory Accelerator Test Facility comprises a 50 MeV traveling wave electron linear accelerator utilizing a high gradient, photo-excited, raidofrequency electron gun as an injector and an experimental area for study of new acceleration methods or advanced radiation sources using free electron lasers. Early operation of the linear accelerator system including calculated and measured beam parameters are presented together with the experimental program for accelerator physics and free electron laser studies.

  19. The Next Linear Collider: NLC2001

    SciTech Connect (OSTI)

    D. Burke et al.

    2002-01-14

    Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider. A first Zeroth-Order Design Report (ZDR) [2] for a second-generation electron-positron linear collider, the Next Linear Collider (NLC), was published five years ago. The NLC design is based on a high-frequency room-temperature rf accelerator. Its goal is exploration of elementary particle physics at the TeV center-of-mass energy, while learning how to design and build colliders at still higher energies. Many advances in accelerator technologies and improvements in the design of the NLC have been made since 1996. This Report is a brief update of the ZDR.

  20. Electron Firehose instability and acceleration of electrons in solar flares

    E-Print Network [OSTI]

    Gunnar Paesold; Arnold O. Benz

    2000-01-14

    An electron distribution with a temperature anisotropy T_par/T_perp > 1 can lead to the Electron Firehose instability (Here par and perp denote directions relative to the background magnetic field B_0). Since possible particle acceleration mechanisms in solar flares exhibit a preference of energizing particles in parallel direction, such an anisotropy is expected during the impulsive phase of a flare. The properties of the excited waves and the thresholds for instability are investigated by using linearized kinetic theory. These thresholds were connected to the pre-flare plasma parameters by assuming an acceleration model acting exclusively in parallel direction. For usually assumed pre-flare plasma conditions the electrons become unstable during the acceleration process and lefthand circularly polarized waves with frequencies of about the proton gyrofrequency are excited at parallel propagation. Indications have been found, that the largest growth rates occur at oblique propagation and the according frequencies lie well above the proton gyrofrequency.

  1. Compact X-ray Free Electron Laser from a Laser-plasma Accelerator...

    Office of Scientific and Technical Information (OSTI)

    Language: English Subject: 43 PARTICLE ACCELERATORS; ACCELERATORS; ELECTRON BEAMS; ELECTRONS; FREE ELECTRON LASERS; LASERS; PERFORMANCE; PLASMA GUNS; RADIATIONS; WIGGLER MAGNETS...

  2. A study of the effect of in-line and perpendicular magnetic fields on beam characteristics of electron guns in medical linear accelerators

    SciTech Connect (OSTI)

    Constantin, Dragos E.; Fahrig, Rebecca; Keall, Paul J.

    2011-07-15

    Purpose: Using magnetic resonance imaging (MRI) for real-time guidance during radiotherapy is an active area of research and development. One aspect of the problem is the influence of the MRI scanner, modeled here as an external magnetic field, on the medical linear accelerator (linac) components. The present work characterizes the behavior of two medical linac electron guns with external magnetic fields for in-line and perpendicular orientations of the linac with respect to the MRI scanner. Methods: Two electron guns, Litton L-2087 and Varian VTC6364, are considered as representative models for this study. Emphasis was placed on the in-line design approach in which case the MRI scanner and the linac axes of symmetry coincide and assumes no magnetic shielding of the linac. For the in-line case, the magnetic field from a 0.5 T open MRI (GE Signa SP) magnet with a 60 cm gap between its poles was computed and used in full three dimensional (3D) space charge simulations, whereas for the perpendicular case the magnetic field was constant. Results: For the in-line configuration, it is shown that the electron beam is not deflected from the axis of symmetry of the gun and the primary beam current does not vanish even at very high values of the magnetic field, e.g., 0.16 T. As the field strength increases, the primary beam current has an initial plateau of constant value after which its value decreases to a minimum corresponding to a field strength of approximately 0.06 T. After the minimum is reached, the current starts to increase slowly. For the case when the beam current computation is performed at the beam waist position the initial plateau ends at 0.016 T for Litton L-2087 and at 0.012 T for Varian VTC6364. The minimum value of the primary beam current is 27.5% of the initial value for Litton L-2087 and 22.9% of the initial value for Varian VTC6364. The minimum current is reached at 0.06 and 0.062 T for Litton L-2087 and Varian VTC6364, respectively. At 0.16 T the beam current increases to 40.2 and 31.4% from the original value of the current for Litton L-2087 and Varian VTC6364, respectively. In contrast, for the case when the electron gun is perpendicular to the magnetic field, the electron beam is deflected from the axis of symmetry even at small values of the magnetic field. As the strength of the magnetic field increases, so does the beam deflection, leading to a sharp decrease of the primary beam current which vanishes at about 0.007 T for Litton L-2087 and at 0.006 T for Varian VTC6364, respectively. At zero external field, the beam rms emittance computed at beam waist is 1.54 and 1.29{pi}-mm-mrad for Litton L-2087 and Varian VTC6364, respectively. For the in-line configuration, there are two particular values of the external field where the beam rms emittance reaches a minimum. Litton L-2087 rms emittance reaches a minimum of 0.72{pi} and 2.01{pi}-mm-mrad at 0.026 and 0.132 T, respectively. Varian VTC6364 rms emittance reaches a minimum of 0.34{pi} and 0.35{pi}-mm-mrad at 0.028 and 0.14 T, respectively. Beam radius dependence on the external field is shown for the in-line configuration for both electron guns. Conclusions: 3D space charge simulation of two electron guns, Litton L-2087 and Varian VTC6364, were performed for in-line and perpendicular external magnetic fields. A consistent behavior of Pierce guns in external magnetic fields was proven. For the in-line configuration, the primary beam current does not vanish but a large reduction of beam current (up to 77.1%) is observed at higher field strengths; the beam directionality remains unchanged. It was shown that for a perpendicular configuration the current vanishes due to beam bending under the action of the Lorentz force. For in-line configuration it was determined that the rms beam emittance reaches two minima for relatively high values of the external magnetic field.

  3. Proceedings of a workshop on Applications of Accelerators

    SciTech Connect (OSTI)

    Herrmannsfeldt, W.B. [ed.] [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Sessler, A.M.; Alonso, J.R. [eds.] [Lawrence Berkeley Lab., CA (United States)

    1994-01-31

    This document is a compilation of material collected as the results of a workshop, Applications of Accelerators, held at the Stanford Linear Accelerator Center, 1--2 December 1993. The material collected here has been edited for style and to minimize duplication. Footnotes will identify the original source of the material. We believe that the reader will find that this document has something for every interest. There are applications in the fields of health, food preservation, energy, environmental monitoring and protection, and industrial processing. Man y of the examples discussed have already passed the demonstration stage. Most of the others are the subject of active accelerator research. Taken as a whole, the particle accelerator field contains a wealth of application opportunities, some already in use, and many more ready to be exploited.

  4. Beam-driven acceleration in ultra-dense plasma media

    SciTech Connect (OSTI)

    Shin, Young-Min [Department of Physics, Northern Illinois University, Dekalb, Illinois 60115 (United States); Accelerator Physics Center (APC), Fermi National Accelerator Laboratory (FNAL), Batavia, Illinois 60510 (United States)

    2014-09-15

    Accelerating parameters of beam-driven wakefield acceleration in an extremely dense plasma column has been analyzed with the dynamic framed particle-in-cell plasma simulator, and compared with analytic calculations. In the model, a witness beam undergoes a TeV/m scale alternating potential gradient excited by a micro-bunched drive beam in a 10{sup 25?}m{sup ?3} and 1.6?×?10{sup 28?}m{sup ?3} plasma column. The acceleration gradient, energy gain, and transformer ratio have been extensively studied in quasi-linear, linear-, and blowout-regimes. The simulation analysis indicated that in the beam-driven acceleration system a hollow plasma channel offers ?20% higher acceleration gradient by enlarging the channel radius (r) from 0.2 ?{sub p} to 0.6 ?{sub p} in a blowout regime. This paper suggests a feasibility of TeV/m scale acceleration with a hollow crystalline structure (e.g., nanotubes) of high electron plasma density.

  5. Beam-driven acceleration in ultra-dense plasma media

    SciTech Connect (OSTI)

    Shin, Young-Min [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States). Accelerator Physics Center

    2014-09-15

    Accelerating parameters of beam-driven wakefield acceleration in an extremely dense plasma column has been analyzed with the dynamic framed particle-in-cell plasma simulator, and compared with analytic calculations. In the model, a witness beam undergoes a TeV/m scale alternating potential gradient excited by a micro-bunched drive beam in a 1025 m-3 and 1.6 x 1028 m-3 plasma column. The acceleration gradient, energy gain, and transformer ratio have been extensively studied in quasi-linear, linear-, and blowout-regimes. The simulation analysis indicated that in the beam-driven acceleration system a hollow plasma channel offers 20 % higher acceleration gradient by enlarging the channel radius (r) from 0.2 ?p to 0.6 ?p in a blowout regime. This paper suggests a feasibility of TeV/m scale acceleration with a hollow crystalline structure (e.g. nanotubes) of high electron plasma density.

  6. Cosmic ray acceleration at perpendicular shocks in supernova remnants

    SciTech Connect (OSTI)

    Ferrand, Gilles; Danos, Rebecca J.; Shalchi, Andreas; Safi-Harb, Samar; Edmon, Paul; Mendygral, Peter

    2014-09-10

    Supernova remnants (SNRs) are believed to accelerate particles up to high energies through the mechanism of diffusive shock acceleration (DSA). Except for direct plasma simulations, all modeling efforts must rely on a given form of the diffusion coefficient, a key parameter that embodies the interactions of energetic charged particles with magnetic turbulence. The so-called Bohm limit is commonly employed. In this paper, we revisit the question of acceleration at perpendicular shocks, by employing a realistic model of perpendicular diffusion. Our coefficient reduces to a power law in momentum for low momenta (of index ?), but becomes independent of the particle momentum at high momenta (reaching a constant value ?{sub ?} above some characteristic momentum p {sub c}). We first provide simple analytical expressions of the maximum momentum that can be reached at a given time with this coefficient. Then we perform time-dependent numerical simulations to investigate the shape of the particle distribution that can be obtained when the particle pressure back-reacts on the flow. We observe that for a given index ? and injection level, the shock modifications are similar for different possible values of p {sub c}, whereas the particle spectra differ markedly. Of particular interest, low values of p {sub c} tend to remove the concavity once thought to be typical of non-linear DSA, and result in steep spectra, as required by recent high-energy observations of Galactic SNRs.

  7. A Linac Simulation Code for Macro-Particles Tracking and Steering Algorithm Implementation

    SciTech Connect (OSTI)

    sun, yipeng

    2012-05-03

    In this paper, a linac simulation code written in Fortran90 is presented and several simulation examples are given. This code is optimized to implement linac alignment and steering algorithms, and evaluate the accelerator errors such as RF phase and acceleration gradient, quadrupole and BPM misalignment. It can track a single particle or a bunch of particles through normal linear accelerator elements such as quadrupole, RF cavity, dipole corrector and drift space. One-to-one steering algorithm and a global alignment (steering) algorithm are implemented in this code.

  8. Carrigan, Jr., Richard A. [Fermi National Accelerator Lab. (FNAL...

    Office of Scientific and Technical Information (OSTI)

    Accelerator Lab. (FNAL), Batavia, IL (United States) 43 PARTICLE ACCELERATORS; BEAM OPTICS; CHANNELING; ATTENUATION; BEAM EXTRACTION; BENDING; CRYSTALS; MESON BEAMS; BEAMS;...

  9. Solar Flares and particle acceleration

    E-Print Network [OSTI]

    energy ~2 1032 ergs #12;"Standard" model of a solar flare/CME Solar corona T ~ 106 K => 0.1 keV per MeV Proton energies >100 MeV Large solar flare releases about 1032 ergs (about half energy-free emission) #12;X-ray spectrum of solar flares Thermal X-rays Non-thermal X-rays Gamma-ray lines Ramaty High

  10. Advanced Modeling for Particle Accelerators

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News Publications Traditional Knowledge KiosksAboutHelp & Reference UsersAdvancedAdvanced

  11. A unified cosmic evolution: Inflation to late time acceleration

    E-Print Network [OSTI]

    Subenoy Chakraborty; Supriya Pan; Subhajit Saha

    2015-04-30

    The present work deals with a cosmological model having particle creation mechanism in the framework of irreversible thermodynamics. In the second order non-equilibrium thermodynamical prescription, the particle creation rate is treated as the dissipative effect. The non-equilibrium thermodynamical process is assumed to be isentropic, and, as a consequence, the entropy per particle is constant, and, hence, the dissipative pressure can be expressed linearly in terms of the particle creation rate in the background of the homogeneous and isotropic flat FLRW model. By proper choice of the particle creation rate as a function of the Hubble parameter, the model shows the evolution of the universe starting from the inflationary scenario to the present accelerating phase, considering the cosmic matter as normal perfect fluid with barotropic equation of state.

  12. Symposium report on frontier applications of accelerators

    SciTech Connect (OSTI)

    Parsa, Z.

    1993-09-28

    This report contains viewgraph material on the following topics: Electron-Positron Linear Colliders; Unconventional Colliders; Prospects for UVFEL; Accelerator Based Intense Spallation; Neutron Sources; and B Physics at Hadron Accelerators with RHIC as an Example.

  13. International linear collider reference design report

    SciTech Connect (OSTI)

    Aarons, G.

    2007-06-22

    The International Linear Collider will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. A proposed electron-positron collider, the ILC will complement the Large Hadron Collider, a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, together unlocking some of the deepest mysteries in the universe. With LHC discoveries pointing the way, the ILC -- a true precision machine -- will provide the missing pieces of the puzzle. Consisting of two linear accelerators that face each other, the ILC will hurl some 10 billion electrons and their anti-particles, positrons, toward each other at nearly the speed of light. Superconducting accelerator cavities operating at temperatures near absolute zero give the particles more and more energy until they smash in a blazing crossfire at the centre of the machine. Stretching approximately 35 kilometres in length, the beams collide 14,000 times every second at extremely high energies -- 500 billion-electron-volts (GeV). Each spectacular collision creates an array of new particles that could answer some of the most fundamental questions of all time. The current baseline design allows for an upgrade to a 50-kilometre, 1 trillion-electron-volt (TeV) machine during the second stage of the project. This reference design provides the first detailed technical snapshot of the proposed future electron-positron collider, defining in detail the technical parameters and components that make up each section of the 31-kilometer long accelerator. The report will guide the development of the worldwide R&D program, motivate international industrial studies and serve as the basis for the final engineering design needed to make an official project proposal later this decade.

  14. Particle acceleration and jet dynamics in Centaurus A Martin J. Hardcastle a , Diana M. Worrall a , Ralph P. Kraft b , W.R. Forman b , C. Jones b and S.S. Murray b

    E-Print Network [OSTI]

    Hardcastle, Martin

    1 Particle acceleration and jet dynamics in Centaurus A Martin J. Hardcastle a , Diana M. Worrall-dynamic range VLA data, have allowed us to relate the radio and X-ray structure of the jet in Cen A to the jet dynamics. We present evidence that a signi#12;cant fraction of the structure in the Cen A X-ray jet is due

  15. PULSED-FOCUSING RECIRCULATING LINACS FOR MUON ACCELERATION

    SciTech Connect (OSTI)

    Johnson, Rolland PAUL

    2014-12-31

    Since the muon has a short lifetime, fast acceleration is essential for high-energy applications such as muon colliders, Higgs factories, or neutrino factories. The best one can do is to make a linear accelerator with the highest possible accelerating gradient to make the accelerating time as short as possible. However, the cost of such a single linear accelerator is prohibitively large due to expensive power sources, cavities, tunnels, and related infrastructure. As was demonstrated in the Thomas Jefferson Accelerator Facility (Jefferson Lab) Continuous Electron Beam Accelerator Facility (CEBAF), an elegant solution to reduce cost is to use magnetic return arcs to recirculate the beam through the accelerating RF cavities many times, where they gain energy on each pass. In such a Recirculating Linear Accelerator (RLA), the magnetic focusing strength diminishes as the beam energy increases in a conventional linac that has constant strength quadrupoles. After some number of passes the focusing strength is insufficient to keep the beam from going unstable and being lost. In this project, the use of fast pulsed quadrupoles in the linac sections was considered for stronger focusing as a function of time to allow more successive passes of a muon beam in a recirculating linear accelerator. In one simulation, it was shown that the number of passes could be increased from 8 to 12 using pulsed magnet designs that have been developed and tested. This could reduce the cost of linac sections of a muon RLA by 8/12, where more improvement is still possible. The expense of a greater number of passes and corresponding number of return arcs was also addressed in this project by exploring the use of ramped or FFAG-style magnets in the return arcs. A better solution, invented in this project, is to use combined-function dipole-quadrupole magnets to simultaneously transport two beams of different energies through one magnet string to reduce costs of return arcs by almost a factor of two. A patent application was filed for this invention and a detailed report published in Physical Review Special Topics. A scaled model using an electron beam was developed and proposed to test the concept of a dog bone RLA with combined-function return arcs. The efforts supported by this grant were reported in a series of contributions to particle accelerator conferences that are reproduced in the appendices and summarized in the body of this report.

  16. The MESA accelerator

    SciTech Connect (OSTI)

    Aulenbacher, Kurt [Institut für Kernphysik, Johannnes-Gutenberg-Universität Mainz (Germany)

    2013-11-07

    The MESA accelerator will operate for particle and nuclear physics experiments in two different modes. A first option is conventional c.w. acceleration yielding 150-200MeV spin-polarized external beam. Second, MESA will be operated as a superconducting multi-turn energy recovery linac (ERL), opening the opportunity to perform experiments with a windowless target with beam current of up to 10 mA. The perspectives for innovative experiments with such a machine are discussed together with a sketch of the accelerator physics issues that have to be solved.

  17. Use of incomplete energy recovery for the energy compression of large energy spread charged particle beams

    DOE Patents [OSTI]

    Douglas, David R. (Newport News, VA); Benson, Stephen V. (Yorktown, VA)

    2007-01-23

    A method of energy recovery for RF-base linear charged particle accelerators that allows energy recovery without large relative momentum spread of the particle beam involving first accelerating a waveform particle beam having a crest and a centroid with an injection energy E.sub.o with the centroid of the particle beam at a phase offset f.sub.o from the crest of the accelerating waveform to an energy E.sub.full and then recovering the beam energy centroid a phase f.sub.o+Df relative to the crest of the waveform particle beam such that (E.sub.full-E.sub.o)(1+cos(f.sub.o+Df))>dE/2 wherein dE=the full energy spread, dE/2=the full energy half spread and Df=the wave form phase distance.

  18. CLIC e+e- Linear Collider Studies

    E-Print Network [OSTI]

    Dominik Dannheim; Philippe Lebrun; Lucie Linssen; Daniel Schulte; Frank Simon; Steinar Stapnes; Nobukazu Toge; Harry Weerts; James Wells

    2012-08-07

    This document provides input from the CLIC e+e- linear collider studies to the update process of the European Strategy for Particle Physics. It is submitted on behalf of the CLIC/CTF3 collaboration and the CLIC physics and detector study. It describes the exploration of fundamental questions in particle physics at the energy frontier with a future TeV-scale e+e- linear collider based on the Compact Linear Collider (CLIC) two-beam acceleration technique. A high-luminosity high-energy e+e- collider allows for the exploration of Standard Model physics, such as precise measurements of the Higgs, top and gauge sectors, as well as for a multitude of searches for New Physics, either through direct discovery or indirectly, via high-precision observables. Given the current state of knowledge, following the observation of a \\sim125 GeV Higgs-like particle at the LHC, and pending further LHC results at 8 TeV and 14 TeV, a linear e+e- collider built and operated in centre-of-mass energy stages from a few-hundred GeV up to a few TeV will be an ideal physics exploration tool, complementing the LHC. Two example scenarios are presented for a CLIC accelerator built in three main stages of 500 GeV, 1.4 (1.5) TeV, and 3 TeV, together with the layout and performance of the experiments and accompanied by cost estimates. The resulting CLIC physics potential and measurement precisions are illustrated through detector simulations under realistic beam conditions.

  19. Accelerator on a Chip: How It Works

    SciTech Connect (OSTI)

    2014-06-30

    In an advance that could dramatically shrink particle accelerators for science and medicine, researchers used a laser to accelerate electrons at a rate 10 times higher than conventional technology in a nanostructured glass chip smaller than a grain of rice.

  20. Acceleration of relativistic electrons by magnetohydrodynamic turbulence: Implications for non-thermal emission from black hole accretion disks

    SciTech Connect (OSTI)

    Lynn, Jacob W.; Quataert, Eliot; Chandran, Benjamin D. G.; Parrish, Ian J.

    2014-08-10

    We use analytic estimates and numerical simulations of test particles interacting with magnetohydrodynamic (MHD) turbulence to show that subsonic MHD turbulence produces efficient second-order Fermi acceleration of relativistic particles. This acceleration is not well described by standard quasi-linear theory but is a consequence of resonance broadening of wave-particle interactions in MHD turbulence. We provide momentum diffusion coefficients that can be used for astrophysical and heliospheric applications and discuss the implications of our results for accretion flows onto black holes. In particular, we show that particle acceleration by subsonic turbulence in radiatively inefficient accretion flows can produce a non-thermal tail in the electron distribution function that is likely important for modeling and interpreting the emission from low-luminosity systems such as Sgr A* and M87.

  1. Accelerators and the Accelerator Community

    E-Print Network [OSTI]

    Malamud, Ernest

    2009-01-01

    such as the International Linear Collider (ILC). In 2008, acollider: the International Linear Collider (ILC). Just what

  2. Method of Linear Invariants for description of beam dynamics of FEL undulator

    E-Print Network [OSTI]

    A. Angelow; D. Trifonov; V. Angelov; H. Hristov

    2008-05-23

    We propose a new model for description of electrons beam dynamics in Free Electron Laser (FEL) undulator, based on the method of linear time-dependent invariants of quantum-mechanical charge particle. The magnetic field has periodic structure along the undulator. For this problem, described by time-dependent quadratic Hamiltonian, we obtain exact solution. The time-evolutions of the tree quantum fluctuations: covariance cov(q,p), var(q) and var(p) for the charge particle in this case are also determined. This research will help to optimize the FEL undulator: for example, using a 2.5 GeV linear electron accelerator it will be possible to emit radiation at 1.5 nm and shorter length. This method could be applicable also to any device with periodic structure of applied field (e.g. Tokamak, cyclic accelerators) for the case of charge non-relativistic quantum particles.

  3. THE RADIOLOGICAL RESEARCH ACCELERATOR FACILITY The Radiological Research Accelerator Facility

    E-Print Network [OSTI]

    THE RADIOLOGICAL RESEARCH ACCELERATOR FACILITY 71 The Radiological Research Accelerator Facility the irradiated cells. Both the microbeam and the track segment facilities continue to be utilized in various investigations of this phenomenon. The single- particle microbeam facility provides precise control of the number

  4. THE RADIOLOGICAL RESEARCH ACCELERATOR FACILITY The Radiological Research Accelerator Facility

    E-Print Network [OSTI]

    THE RADIOLOGICAL RESEARCH ACCELERATOR FACILITY 1 The Radiological Research Accelerator Facility for Radiological Research (CRR). Using the mi- crobeam facility, 10% of the cells were irradiated through particle beam as well as the first fo- cused microbeam in the new microbeam facility. · Another significant

  5. ACCELERATORS: ENGINES FOR TRAVERSING A LARGE AND OFTEN DIFFICULT LANDSCAPE

    E-Print Network [OSTI]

    Sessler, Andrew M.

    2014-01-01

    California. ACCELERATORS: ENGINES FOR TRAVERSING A LARGE ANDthat go with them, are from: “Engines of Discovery: Particle

  6. THE RADIOLOGICAL RESEARCH ACCELERATOR FACILITY

    E-Print Network [OSTI]

    THE RADIOLOGICAL RESEARCH ACCELERATOR FACILITY #12;115 THE RADIOLOGICAL RESEARCH ACCELERATOR FACILITY An NIH-Supported Resource Center WWW.RARAF.ORG Director: David J. Brenner, Ph.D., D.Sc. Manager delighted that NIH funding for continued development of our single-particle microbeam facility was renewed

  7. Laser acceleration of ion beams

    E-Print Network [OSTI]

    I. A. Egorova; A. V. Filatov; A. V. Prozorkevich; S. A. Smolyansky; D. B. Blaschke; M. Chubaryan

    2007-02-01

    We consider methods of charged particle acceleration by means of high-intensity lasers. As an application we discuss a laser booster for heavy ion beams provided, e.g. by the Dubna nuclotron. Simple estimates show that a cascade of crossed laser beams would be necessary to provide additional acceleration to gold ions of the order of GeV/nucleon.

  8. The International Linear Collider

    E-Print Network [OSTI]

    Jim Brau; Paul Grannis; Mike Harrison; Michael Peskin; Marc Ross; Harry Weerts

    2013-04-09

    We present a brief summary of the International Linear Collider as documented in the 2013 Technical Design Report. The Technical Design Report has detailed descriptions of the accelerator baseline design for a 500 GeV e+e- linear collider, the R&D program that has demonstrated its feasibility, the physics goals and expected sensitivities, and the description of the ILD and SiD detectors and their capabilities.

  9. Sequentially pulsed traveling wave accelerator

    DOE Patents [OSTI]

    Caporaso, George J. (Livermore, CA); Nelson, Scott D. (Patterson, CA); Poole, Brian R. (Tracy, CA)

    2009-08-18

    A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

  10. Acceleration and Enrichment of 3He in Impulsive Solar Flares by Electron Firehose Waves

    E-Print Network [OSTI]

    G. Paesold; R. Kallenbach; A. O. Benz

    2002-09-08

    A new mechanism for acceleration and enrichment of 3He during impulsive solar flares is presented. Low-frequency electromagnetic plasma waves excited by the Electron Firehose Instability (EFI) can account for the acceleration of ions up to 1 MeV/amu energies as a single stage process. The EFI arises as a direct consequence of the free energy stored in a temperature anisotropy (T_parallel>T_perp) of the bulk energized electron population during the acceleration process. In contrast to other mechanisms which require special plasma properties, the EFI is an intrinsic feature of the acceleration process of the bulk electrons. Being present as a side effect in the flaring plasma, these waves can account for the acceleration of 3He and 4He while selectively enhancing 3He due to the spectral energy density built up from linear growth. Linearized kinetic theory, analytic models and test-particle simulations have been applied to investigate the ability of the waves to accelerate and fractionate. As waves grow in both directions parallel to the magnetic field, they can trap resonant ions and efficiently accelerate them to the highest energies. Plausible models have been found that can explain the observed energies, spectra and abundances of 3He and 4He.

  11. A Linear Theory of Microwave Instability in Electron Storage...

    Office of Scientific and Technical Information (OSTI)

    United States Language: English Subject: 43 PARTICLE ACCELERATORS; DISTRIBUTION; ELECTRONS; INSTABILITY; LAGUERRE POLYNOMIALS; STABILITY; STORAGE RINGS; SYNCHROTRON RADIATION;...

  12. Accelerators for research and applications

    SciTech Connect (OSTI)

    Alonso, J.R.

    1990-06-01

    The newest particle accelerators are almost always built for extending the frontiers of research, at the cutting edge of science and technology. Once these machines are operating and these technologies mature, new applications are always found, many of which touch our lives in profound ways. The evolution of accelerator technologies will be discussed, with descriptions of accelerator types and characteristics. The wide range of applications of accelerators will be discussed, in fields such as nuclear science, medicine, astrophysics and space-sciences, power generation, airport security, materials processing and microcircuit fabrication. 13 figs.

  13. Alfven-wave particle interaction in finite-dimensional self-consistent field model

    SciTech Connect (OSTI)

    Padhye, N.; Horton, W.

    1998-10-09

    A low-dimensional Hamiltonian model is derived for the acceleration of ions in finite amplitude Alfven waves in a finite pressure plasma sheet. The reduced low-dimensional wave-particle Hamiltonian is useful for describing the reaction of the accelerated ions on the wave amplitudes and phases through the self-consistent fields within the envelope approximation. As an example, the authors show for a single Alfven wave in the central plasma sheet of the Earth`s geotail, modeled by the linear pinch geometry called the Harris sheet, the time variation of the wave amplitude during the acceleration of fast protons.

  14. Market Acceleration

    SciTech Connect (OSTI)

    Solar Energy Technologies Program

    2010-09-28

    The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts within its market acceleration subprogram.

  15. Future HEP Accelerators: The US Perspective

    E-Print Network [OSTI]

    Bhat, Pushpalatha

    2015-01-01

    Accelerator technology has advanced tremendously since the introduction of accelerators in the 1930s, and particle accelerators have become indispensable instruments in high energy physics (HEP) research to probe Nature at smaller and smaller distances. At present, accelerator facilities can be classified into Energy Frontier colliders that enable direct discoveries and studies of high mass scale particles and Intensity Frontier accelerators for exploration of extremely rare processes, usually at relatively low energies. The near term strategies of the global energy frontier particle physics community are centered on fully exploiting the physics potential of the Large Hadron Collider (LHC) at CERN through its high-luminosity upgrade (HL-LHC), while the intensity frontier HEP research is focused on studies of neutrinos at the MW-scale beam power accelerator facilities, such as Fermilab Main Injector with the planned PIP-II SRF linac project. A number of next generation accelerator facilities have been proposed...

  16. EM Structure Based and Vacuum Acceleration

    SciTech Connect (OSTI)

    Colby, E.R.; /SLAC

    2005-09-27

    The importance of particle acceleration may be judged from the number of applications which require some sort of accelerated beam. In addition to accelerator-based high energy physics research, non-academic applications include medical imaging and treatment, structural biology by x-ray diffraction, pulse radiography, cargo inspection, material processing, food and medical instrument sterilization, and so on. Many of these applications are already well served by existing technologies and will profit only marginally from developments in accelerator technology. Other applications are poorly served, such as structural biology, which is conducted at synchrotron radiation facilities, and medical treatment using proton accelerators, the machines for which are rare because they are complex and costly. Developments in very compact, high brightness and high gradient accelerators will change how accelerators are used for such applications, and potentially enable new ones. Physical and technical issues governing structure-based and vacuum acceleration of charged particles are reviewed, with emphasis on practical aspects.

  17. particle physics 2009Highlights

    E-Print Network [OSTI]

    Report particle physics 2009ª #12;2 | Contents #12;Contents | 3 contentsª º introduction 4 º News;Introduction | 5 projects, (ii) coordination of national particle physics activities and (iii) reaching outparticle physics 2009ªHighlights and Annual Report Accelerators | Photon Science | Particle Physics

  18. Accelerator simulation using computers

    SciTech Connect (OSTI)

    Lee, M.; Zambre, Y.; Corbett, W.

    1992-01-01

    Every accelerator or storage ring system consists of a charged particle beam propagating through a beam line. Although a number of computer programs exits that simulate the propagation of a beam in a given beam line, only a few provide the capabilities for designing, commissioning and operating the beam line. This paper shows how a ``multi-track`` simulation and analysis code can be used for these applications.

  19. Accelerator simulation using computers

    SciTech Connect (OSTI)

    Lee, M.; Zambre, Y.; Corbett, W.

    1992-01-01

    Every accelerator or storage ring system consists of a charged particle beam propagating through a beam line. Although a number of computer programs exits that simulate the propagation of a beam in a given beam line, only a few provide the capabilities for designing, commissioning and operating the beam line. This paper shows how a multi-track'' simulation and analysis code can be used for these applications.

  20. Linear psoriasis

    E-Print Network [OSTI]

    Jr, Peter Chien; Rosenman, Karla; Cheung, Wang; Wang, Nadia; Sanchez, Miguel

    2009-01-01

    type 1/type 2 mosaic of psoriasis? Dermatology 2006; 212:Magalhaes RF, et al. Linear psoriasis in Brazilian childrensuffering from linear psoriasis along lines of Blaschko. Br

  1. CENTRIPETAL ACCELERATION AND CENTRIFUGAL FORCE IN GENERAL RELATIVITY

    E-Print Network [OSTI]

    Jantzen, Robert T.

    1 CENTRIPETAL ACCELERATION AND CENTRIFUGAL FORCE IN GENERAL RELATIVITY D. BINI Istituto per acceleration which, once interpreted as a centrifugal force acting on the particle, allows writing the particle and centrifugal acceleration generalizing the classical concepts must be properly (geometrically) defined

  2. International Workshop on Linear Colliders 2010

    ScienceCinema (OSTI)

    None

    2011-10-06

    IWLC2010 International Workshop on Linear Colliders 2010ECFA-CLIC-ILC joint meeting: Monday 18 October - Friday 22 October 2010Venue: CERN and CICG (International Conference Centre Geneva, Switzerland) This year, the International Workshop on Linear Colliders organized by the European Committee for Future Accelerators (ECFA) will study the physics, detectors and accelerator complex of a linear collider covering both CLIC and ILC options.Contact Workshop Secretariat  IWLC2010 is hosted by CERN

  3. An Alternative to Particle Dark Matter

    E-Print Network [OSTI]

    Justin Khoury

    2014-12-11

    We propose an alternative to particle dark matter that borrows ingredients of MOdified Newtonian Dynamics (MOND) while adding new key components. The first new feature is a dark matter fluid, in the form of a scalar field with small equation of state and sound speed. This component is critical in reproducing the success of cold dark matter for the expansion history and the growth of linear perturbations, but does not cluster significantly on non-linear scales. Instead, the missing mass problem on non-linear scales is addressed by a modification of the gravitational force law. The force law approximates MOND at large and intermediate accelerations, and therefore reproduces the empirical success of MOND at fitting galactic rotation curves. At ultra-low accelerations, the force law reverts to an inverse-square-law, albeit with a larger Newton's constant. This latter regime is important in galaxy clusters and is consistent with their observed isothermal profiles, provided the characteristic acceleration scale of MOND is mildly varying with scale or mass, such that it is ~12 times higher in clusters than in galaxies. We present an explicit relativistic theory in terms of two scalar fields. The first scalar field is governed by a Dirac-Born-Infeld action and behaves as a dark matter fluid on large scales. The second scalar field also has single-derivative interactions and mediates a fifth force that modifies gravity on non-linear scales. Both scalars are coupled to matter via an effective metric that depends locally on the fields. The form of this effective metric implies the equality of the two scalar gravitational potentials, which ensures that lensing and dynamical mass estimates agree. Further work is needed in order to make both the acceleration scale of MOND and the fraction at which gravity reverts to an inverse-square law explicitly dynamical quantities, varying with scale or mass.

  4. High-energy X-ray imaging of the pulsar wind nebula MSH 15–52: constraints on particle acceleration and transport

    SciTech Connect (OSTI)

    An, Hongjun; Kaspi, Victoria M.; Madsen, Kristin K.; Harrison, Fiona A.; Grefenstette, Brian W.; Reynolds, Stephen P.; Boggs, Steven E.; Craig, William W.; Christensen, Finn E.; Fryer, Chris L.; Hailey, Charles J.; Mori, Kaya; Stern, Daniel; Zhang, William W.

    2014-10-01

    We present the first images of the pulsar wind nebula (PWN) MSH 15–52 in the hard X-ray band (?8 keV), as measured with the Nuclear Spectroscopic Telescope Array (NuSTAR). Overall, the morphology of the PWN as measured by NuSTAR in the 3-7 keV band is similar to that seen in Chandra high-resolution imaging. However, the spatial extent decreases with energy, which we attribute to synchrotron energy losses as the particles move away from the shock. The hard-band maps show a relative deficit of counts in the northern region toward the RCW 89 thermal remnant, with significant asymmetry. We find that the integrated PWN spectra measured with NuSTAR and Chandra suggest that there is a spectral break at 6 keV, which may be explained by a break in the synchrotron-emitting electron distribution at ?200 TeV and/or imperfect cross calibration. We also measure spatially resolved spectra, showing that the spectrum of the PWN softens away from the central pulsar B1509–58, and that there exists a roughly sinusoidal variation of spectral hardness in the azimuthal direction. We discuss the results using particle flow models. We find non-monotonic structure in the variation with distance of spectral hardness within 50'' of the pulsar moving in the jet direction, which may imply particle and magnetic-field compression by magnetic hoop stress as previously suggested for this source. We also present two-dimensional maps of spectral parameters and find an interesting shell-like structure in the N {sub H} map. We discuss possible origins of the shell-like structure and their implications.

  5. Accelerators and the Accelerator Community

    E-Print Network [OSTI]

    Malamud, Ernest

    2009-01-01

    became the APS Division of the Physics of Beams. If oneorganizes accelerator physics sessions at APS meetings, and,creating the APS topical group on beam physics, which later

  6. Cascaded target normal sheath acceleration

    SciTech Connect (OSTI)

    Wang, W. P.; Shen, B. F.; Zhang, X. M.; Wang, X. F.; Xu, J. C.; Zhao, X. Y.; Yu, Y. H.; Yi, L. Q.; Shi, Y.; Zhang, L. G.; Xu, T. J.; Xu, Z. Z.

    2013-11-15

    A cascaded target normal sheath acceleration (TNSA) scheme is proposed to simultaneously increase energy and improve energy spread of a laser-produced mono-energetic proton beam. An optimum condition that uses the maximum sheath field to accelerate the center of the proton beam is theoretically found and verified by two-dimensional particle-in-cell simulations. An initial 10 MeV proton beam is accelerated to 21 MeV with energy spread decreased from 5% to 2% under the optimum condition during the process of the cascaded TNSA. The scheme opens a way to scale proton energy lineally with laser energy.

  7. Discovery of Optical Emission in the Hotspots of Three 3CR Quasars: High-Energy Particle Acceleration in Powerful Radio Hotspots

    E-Print Network [OSTI]

    C. C. Cheung; J. F. C. Wardle; T. Chen

    2005-03-29

    Archival Hubble Space Telescope WFPC2 images were used to search for optical emission associated with the radio jets of a number of luminous quasars. From this search, we report new optical hotspot detections in the well-known blazar 3C~454.3 and the lobe-dominated quasars 3C~275.1 and 3C~336. We also find optical emission in the vicinity of the hotspot in 3C~208, but believe this is a chance alignment. Optical emission from the arcsecond-scale jet in 3C~454.3 is also detected. Multi-frequency archival radio data from the VLA and MERLIN are analyzed, and the synchrotron spectra of these high-power hotspots are presented. We estimate that their break frequencies are in the range of $10^{10}-10^{11}$ Hz, with large uncertainties due to the wide gap in frequency coverage between the radio and optical bands. We also calculate their equipartition magnetic fields, and find that the anti-correlation between break frequency and magnetic field found by Brunetti et al. for lower power hotspots extends to these high power hotspots. This supports their model of hot-spots based on shock acceleration and synchrotron losses.

  8. Linear Collider Physics Resource Book Snowmass 2001

    SciTech Connect (OSTI)

    Ronan (Editor), M.T.

    2001-06-01

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup -} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup -} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup -} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup -} experiments can provide. This last point merits further emphasis. If a new accelerator could be designed and built in a few years, it would make sense to wait for the results of each accelerator before planning the next one. Thus, we would wait for the results from the Tevatron before planning the LHC experiments, and wait for the LHC before planning any later stage. In reality accelerators require a long time to construct, and they require such specialized resources and human talent that delay can cripple what would be promising opportunities. In any event, we believe that the case for the linear collider is so compelling and robust that we can justify this facility on the basis of our current knowledge, even before the Tevatron and LHC experiments are done. The physics prospects for the linear collider have been studied intensively for more than a decade, and arguments for the importance of its experimental program have been developed from many different points of view. This book provides an introduction and a guide to this literature. We hope that it will allow physicists new to the consideration of linear collider physics to start from their own personal perspectives and develop their own assessments of the opportunities afforded by a linear collider.

  9. High Performance Computing in Accelerator Science: Past Successes. Future Challenges

    E-Print Network [OSTI]

    Ryne, R.

    2013-01-01

    nuclear physics Particle accelerators have important applications in energy, environment,nuclear material, explosives in cargo • accelerator-driven energy production • studying materials and organisms relevent to energy and the environment —

  10. First Director Named for Center for Accelerator Science | Jefferson...

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

    and is a regular teacher at the U.S. Particle Accelerator School. He is the inventor of several types of accelerating cavities that are being used worldwide. "Jean's...

  11. Future directions of accelerator-based NP and HEP facilities

    SciTech Connect (OSTI)

    Roser, T.

    2011-07-24

    Progress in particle and nuclear physics has been closely connected to the progress in accelerator technologies - a connection that is highly beneficial to both fields. This paper presents a review of the present and future facilities and accelerator technologies that will push the frontiers of high-energy particle interactions and high intensity secondary particle beams.

  12. Accelerator Division

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsicloudden Documentation DataStreamsTotalproposalsAboutAccelerating theAccelerator

  13. Accelerator Systems

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News Publications Traditional Knowledge KiosksAbout UsAbout NewAccelerator Systems Accelerator

  14. Accelerator Technology Division progress report, FY 1992

    SciTech Connect (OSTI)

    Schriber, S.O.; Hardekopf, R.A.; Heighway, E.A.

    1993-07-01

    This report briefly discusses the following topics: The Ground Test Accelerator Program; Defense Free-Electron Lasers; AXY Programs; A Next Generation High-Power Neutron-Scattering Facility; JAERI OMEGA Project and Intense Neutron Sources for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Supercollider; The High-Power Microwave (HPM) Program; Neutral Particle Beam (NPB) Power Systems Highlights; Industrial Partnering; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Accelerator Theory and Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations.

  15. Interplay of Boltzmann equation and continuity equation for accelerated electrons in solar flares

    E-Print Network [OSTI]

    Codispoti, Anna

    2015-01-01

    During solar flares a large amount of electrons are accelerated within the plasma present in the solar atmosphere. Accurate measurements of the motion of these electrons start becoming available from the analysis of hard X-ray imaging-spectroscopy observations. In this paper, we discuss the linearized perturbations of the Boltzmann kinetic equation describing an ensemble of electrons accelerated by the energy release occurring during solar flares. Either in the limit of high energy or at vanishing background temperature such an equation reduces to a continuity equation equipped with an extra force of stochastic nature. This stochastic force is actually described by the well known energy loss rate due to Coulomb collision with ambient particles, but, in order to match the collision kernel in the linearized Boltzmann equation it needs to be treated in a very specific manner. In the second part of the paper the derived continuity equation is solved with some hyperbolic techniques, and the obtained solution is wr...

  16. Design and construction of a cyclotron capable of accelerating protons to 2 MeV

    E-Print Network [OSTI]

    Dewan, Leslie

    2007-01-01

    This thesis describes the design and construction of a cyclotron capable of accelerating protons to 2 MeV. A cyclotron is a charged particle accelerator that uses a magnetic field to confine particles to a spiral flight ...

  17. Beam loading in a laser-plasma accelerator using a near-hollow plasma channel

    SciTech Connect (OSTI)

    Schroeder, C. B.; Benedetti, C.; Esarey, E.; Leemans, W. P.

    2013-12-15

    Beam loading in laser-plasma accelerators using a near-hollow plasma channel is examined in the linear wake regime. It is shown that, by properly shaping and phasing the witness particle beam, high-gradient acceleration can be achieved with high-efficiency, and without induced energy spread or emittance growth. Both electron and positron beams can be accelerated in this plasma channel geometry. Matched propagation of electron beams can be achieved by the focusing force provided by the channel density. For positron beams, matched propagation can be achieved in a hollow plasma channel with external focusing. The efficiency of energy transfer from the wake to a witness beam is calculated for single ultra-short bunches and bunch trains.

  18. Advanced medical accelerator design

    SciTech Connect (OSTI)

    Alonso, J.R.; Elioff, T.; Garren, A.

    1982-11-01

    This report describes the design of an advanced medical facility dedicated to charged particle radiotherapy and other biomedical applications of relativistic heavy ions. Project status is reviewed and some technical aspects discussed. Clinical standards of reliability are regarded as essential features of this facility. Particular emphasis is therefore placed on the control system and on the use of technology which will maximize operational efficiency. The accelerator will produce a variety of heavy ion beams from helium to argon with intensities sufficient to provide delivered dose rates of several hundred rad/minute over large, uniform fields. The technical components consist of a linac injector with multiple PIG ion sources, a synchrotron and a versatile beam delivery system. An overview is given of both design philosophy and selected accelerator subsystems. Finally, a plan of the facility is described.

  19. Linear Dependence and Linear Independence

    E-Print Network [OSTI]

    PRETEX (Halifax NS) #1 1054 1999 Mar 05 10:59:16

    2010-02-12

    Feb 16, 2007 ... Observe that the vector (1, 2) is already a linear combination of (1, 0) and (0, 1), and therefore it does not add any new vectors to the linear span ...

  20. Accelerator target

    DOE Patents [OSTI]

    Schlyer, D.J.; Ferrieri, R.A.; Koehler, C.

    1999-06-29

    A target includes a body having a depression in a front side for holding a sample for irradiation by a particle beam to produce a radioisotope. Cooling fins are disposed on a backside of the body opposite the depression. A foil is joined to the body front side to cover the depression and sample therein. A perforate grid is joined to the body atop the foil for supporting the foil and for transmitting the particle beam therethrough. A coolant is circulated over the fins to cool the body during the particle beam irradiation of the sample in the depression. 5 figs.

  1. Accelerator target

    DOE Patents [OSTI]

    Schlyer, David J. (Bellport, NY); Ferrieri, Richard A. (Patchogue, NY); Koehler, Conrad (Miller Place, NY)

    1999-01-01

    A target includes a body having a depression in a front side for holding a sample for irradiation by a particle beam to produce a radioisotope. Cooling fins are disposed on a backside of the body opposite the depression. A foil is joined to the body front side to cover the depression and sample therein. A perforate grid is joined to the body atop the foil for supporting the foil and for transmitting the particle beam therethrough. A coolant is circulated over the fins to cool the body during the particle beam irradiation of the sample in the depression.

  2. Linear Algebraic Method for Non-Linear Map Analysis

    SciTech Connect (OSTI)

    Yu,L.; Nash, B.

    2009-05-04

    We present a newly developed method to analyze some non-linear dynamics problems such as the Henon map using a matrix analysis method from linear algebra. Choosing the Henon map as an example, we analyze the spectral structure, the tune-amplitude dependence, the variation of tune and amplitude during the particle motion, etc., using the method of Jordan decomposition which is widely used in conventional linear algebra.

  3. Accelerators for Intensity Frontier Research

    SciTech Connect (OSTI)

    Derwent, Paul; /Fermilab

    2012-05-11

    In 2008, the Particle Physics Project Prioritization Panel identified three frontiers for research in high energy physics, the Energy Frontier, the Intensity Frontier, and the Cosmic Frontier. In this paper, I will describe how Fermilab is configuring and upgrading the accelerator complex, prior to the development of Project X, in support of the Intensity Frontier.

  4. Stochastic Acceleration in Relativistic Parallel Shocks

    E-Print Network [OSTI]

    Joni J. P. Virtanen; Rami Vainio

    2004-11-08

    (abridged) We present results of test-particle simulations on both the first and the second order Fermi acceleration at relativistic parallel shock waves. We consider two scenarios for particle injection: (i) particles injected at the shock front, then accelerated at the shock by the first order mechanism and subsequently by the stochastic process in the downstream region; and (ii) particles injected uniformly throughout the downstream region to the stochastic process. We show that regardless of the injection scenario, depending on the magnetic field strength, plasma composition, and the employed turbulence model, the stochastic mechanism can have considerable effects on the particle spectrum on temporal and spatial scales too short to be resolved in extragalactic jets. Stochastic acceleration is shown to be able to produce spectra that are significantly flatter than the limiting case of particle energy spectral index -1 of the first order mechanism. Our study also reveals a possibility of re-acceleration of the stochastically accelerated spectrum at the shock, as particles at high energies become more and more mobile as their mean free path increases with energy. Our findings suggest that the role of the second order mechanism in the turbulent downstream of a relativistic shock with respect to the first order mechanism at the shock front has been underestimated in the past, and that the second order mechanism may have significant effects on the form of the particle spectra and its evolution.

  5. Fermilab | Science | Particle Accelerators | LHC and Future Accelerators

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photo feature photoFermilab'sLHC and

  6. 1 Industrial Electron Accelerators type ILU for Industrial Technologies

    E-Print Network [OSTI]

    1 Industrial Electron Accelerators type ILU for Industrial Technologies The present work describes industrial electron accelerators of the ILU family. Their main parameters, design, principle of action the pulse linear accelerators type ILU are developed and supplied to the industry. The ILU machines

  7. Use of Oriented Crystals at High-Energy Accelerators

    SciTech Connect (OSTI)

    Kotov, V.I.; Afonin, A.G.; Baranov, V.T.; Biryukov, V.M.; Ivanov, Yu.M.; Kardash, A.A.; Maisheev, V.A.; Terekhov, V.I.; Troyanov, E.F.; Fedotov, Yu.S.; Chepegin, V.N.; Chesnokov, Yu.A.

    2005-06-01

    The application of bent crystals for extracting accelerated beams from high-energy accelerators is reviewed. The results of realizing highly efficient extraction of protons from the IHEP accelerator are presented. Proposals on using oriented crystals for designing efficient positron sources at linear colliders and on developing new undulators are discussed.

  8. Basic non-linear effects in silicon radiation detector in detection of highly ionizing particles: registration of ultra rare events of superheavy nuclei in the long-term experiments

    E-Print Network [OSTI]

    Tsyganov, Y S

    2015-01-01

    Sources of non-linear response of PIPS detector, when detecting highly ionizing particles like recoils (EVR), fission fragments and heavy ions, including formation of large pulse-height defect (PHD) are considered. An analytical formula to calculate the recombination component of EVR PHD is proposed on the base of surface recombination model with some empirical correction. PC-based simulation code for generating the spectrum of the measured recoil signal amplitudes of the heavy implanted nuclei is presented. The simulated spectra are compared with the experimental ones for the different facilities: the Dubna Gas Filled Recoil Separator (DGFRS), SHIP and RIKEN gas-filled separator. After the short reviewing of the detection system of the DGFRS, is considered the real-time matrix algorithm application aimed to the radical background suppression in the complete-fusion heavy-ion induced nuclear reactions. Typical examples of application in the long term experiments aimed to the synthesis of superheavy elements Z=...

  9. Community Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies

    SciTech Connect (OSTI)

    Spentzouris, P.; /Fermilab; Cary, J.; /Tech-X, Boulder; McInnes, L.C.; /Argonne; Mori, W.; /UCLA; Ng, C.; /SLAC; Ng, E.; Ryne, R.; /LBL, Berkeley

    2011-11-14

    The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors. ComPASS is in the first year of executing its plan to develop the next-generation HPC accelerator modeling tools. ComPASS aims to develop an integrated simulation environment that will utilize existing and new accelerator physics modules with petascale capabilities, by employing modern computing and solver technologies. The ComPASS vision is to deliver to accelerator scientists a virtual accelerator and virtual prototyping modeling environment, with the necessary multiphysics, multiscale capabilities. The plan for this development includes delivering accelerator modeling applications appropriate for each stage of the ComPASS software evolution. Such applications are already being used to address challenging problems in accelerator design and optimization. The ComPASS organization for software development and applications accounts for the natural domain areas (beam dynamics, electromagnetics, and advanced acceleration), and all areas depend on the enabling technologies activities, such as solvers and component technology, to deliver the desired performance and integrated simulation environment. The ComPASS applications focus on computationally challenging problems important for design or performance optimization to all major HEP, NP, and BES accelerator facilities. With the cost and complexity of particle accelerators rising, the use of computation to optimize their designs and find improved operating regimes becomes essential, potentially leading to significant cost savings with modest investment.

  10. Accelerators and the Accelerator Community

    SciTech Connect (OSTI)

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  11. Peculiar acceleration

    E-Print Network [OSTI]

    Luca Amendola; Claudia Quercellini; Amedeo Balbi

    2007-08-08

    It has been proposed recently to observe the change in cosmological redshift of distant galaxies or quasars with the next generation of large telescope and ultra-stable spectrographs (the so-called Sandage-Loeb test). Here we investigate the possibility of observing the change in peculiar velocity in nearby clusters and galaxies. This ``peculiar acceleration'' could help reconstructing the gravitational potential without assuming virialization. We show that the expected effect is of the same order of magnitude of the cosmological velocity shift. Finally, we discuss how to convert the theoretical predictions into quantities directly related to observations.

  12. Acceleration Fund

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsicloudden Documentation DataStreamsTotalproposalsAboutAccelerating the transfer

  13. SuperB Progress Report for Accelerator

    SciTech Connect (OSTI)

    Biagini, M.E.; Boni, R.; Boscolo, M.; Buonomo, B.; Demma, T.; Drago, A.; Esposito, M.; Guiducci, S.; Mazzitelli, G.; Pellegrino, L.; Preger, M.A.; Raimondi, P.; Ricci, R.; Rotundo, U.; Sanelli, C.; Serio, M.; Stella, A.; Tomassini, S.; Zobov, M.; Bertsche, K.; Brachman, A.; /SLAC /Novosibirsk, IYF /INFN, Pisa /Pisa U. /Orsay, LAL /Annecy, LAPP /LPSC, Grenoble /IRFU, SPP, Saclay /DESY /Cockroft Inst. Accel. Sci. Tech. /U. Liverpool /CERN

    2012-02-14

    This report details the progress made in by the SuperB Project in the area of the Collider since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008. With this document we propose a new electron positron colliding beam accelerator to be built in Italy to study flavor physics in the B-meson system at an energy of 10 GeV in the center-of-mass. This facility is called a high luminosity B-factory with a project name 'SuperB'. This project builds on a long history of successful e+e- colliders built around the world, as illustrated in Figure 1.1. The key advances in the design of this accelerator come from recent successes at the DAFNE collider at INFN in Frascati, Italy, at PEP-II at SLAC in California, USA, and at KEKB at KEK in Tsukuba Japan, and from new concepts in beam manipulation at the interaction region (IP) called 'crab waist'. This new collider comprises of two colliding beam rings, one at 4.2 GeV and one at 6.7 GeV, a common interaction region, a new injection system at full beam energies, and one of the two beams longitudinally polarized at the IP. Most of the new accelerator techniques needed for this collider have been achieved at other recently completed accelerators including the new PETRA-3 light source at DESY in Hamburg (Germany) and the upgraded DAFNE collider at the INFN laboratory at Frascati (Italy), or during design studies of CLIC or the International Linear Collider (ILC). The project is to be designed and constructed by a worldwide collaboration of accelerator and engineering staff along with ties to industry. To save significant construction costs, many components from the PEP-II collider at SLAC will be recycled and used in this new accelerator. The interaction region will be designed in collaboration with the particle physics detector to guarantee successful mutual use. The accelerator collaboration will consist of several groups at present universities and national laboratories. In Italy these may include INFN Frascati and the University of Pisa, in the United States SLAC, LBNL, BNL and several universities, in France IN2P3, LAPP, and Grenoble, in Russia BINP, in Poland Krakow University, and in the UK the Cockcroft Institute. The construction time for this collider is a total of about four years. The new tunnel can be bored in about a year. The new accelerator components can be built and installed in about 4 years. The shipping of components from PEP-II at SLAC to Italy will take about a year. A new linac and damping ring complex for the injector for the rings can be built in about three years. The commissioning of this new accelerator will take about a year including the new electron and positron sources, new linac, new damping ring, new beam transport lines, two new collider rings and the Interaction Region. The new particle physics detector can be commissioned simultaneously with the accelerator. Once beam collisions start for particle physics, the luminosity will increase with time, likely reaching full design specifications after about two to three years of operation. After construction, the operation of the collider will be the responsibility of the Italian INFN governmental agency. The intent is to run this accelerator about ten months each year with about one month for accelerator turn-on and nine months for colliding beams. The collider will need to operate for about 10 years to provide the required 50 ab{sup -1} requested by the detector collaboration. Both beams as anticipated in this collider will have properties that are excellent for use as sources for synchrotron radiation (SR). The expected photon properties are comparable to those of PETRA-3 or NSLS-II. The beam lines and user facilities needed to carry out this SR program are being investigated.

  14. Commnity Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies

    SciTech Connect (OSTI)

    Spentzouris, Panagiotis; /Fermilab; Cary, John; /Tech-X, Boulder; Mcinnes, Lois Curfman; /Argonne; Mori, Warren; /UCLA; Ng, Cho; /SLAC; Ng, Esmond; Ryne, Robert; /LBL, Berkeley

    2008-07-01

    The design and performance optimization of particle accelerators is essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC1 Accelerator Science and Technology project, the SciDAC2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modeling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multi-physics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.

  15. Commnity Petascale Project for Accelerator Science And Simulation: Advancing Computational Science for Future Accelerators And Accelerator Technologies

    SciTech Connect (OSTI)

    Spentzouris, Panagiotis; /Fermilab; Cary, John; /Tech-X, Boulder; Mcinnes, Lois Curfman; /Argonne; Mori, Warren; /UCLA; Ng, Cho; /SLAC; Ng, Esmond; Ryne, Robert; /LBL, Berkeley

    2011-10-21

    The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.

  16. Electron Cloud Effects in Accelerators

    SciTech Connect (OSTI)

    Furman, M.A.

    2012-11-30

    Abstract We present a brief summary of various aspects of the electron-cloud effect (ECE) in accelerators. For further details, the reader is encouraged to refer to the proceedings of many prior workshops, either dedicated to EC or with significant EC contents, including the entire ?ECLOUD? series [1?22]. In addition, the proceedings of the various flavors of Particle Accelerator Conferences [23] contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series [24] contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC [25].

  17. Operation of the Brookhaven National Laboratory Accelerator Test Facility

    SciTech Connect (OSTI)

    Batchelor, K.; Ben-Zvi, I.; Botke, I.; Chou, T.S.; Fernow, R.; Fischer, J.; Fisher, A.; Gallardo, J.; Ingold, G.; Malone, R.; Palmer, R.; Parsa, Z.; Pogorelsky, I.; Rogers, J.; Sheehan, J.; Srinivasan-Rao, T.; Tsang, T.; Ulc, S.; van Steenbergen, A.; Wang, X.J.; Woodle, M.; Yu, L.H.

    1992-01-01

    Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program.

  18. Operation of the Brookhaven National Laboratory Accelerator Test Facility

    SciTech Connect (OSTI)

    Batchelor, K.; Ben-Zvi, I.; Botke, I.; Chou, T.S.; Fernow, R.; Fischer, J.; Fisher, A.; Gallardo, J.; Ingold, G.; Malone, R.; Palmer, R.; Parsa, Z.; Pogorelsky, I.; Rogers, J.; Sheehan, J.; Srinivasan-Rao, T.; Tsang, T.; Ulc, S.; van Steenbergen, A.; Wang, X.J.; Woodle, M.; Yu, L.H.

    1992-10-01

    Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program.

  19. LASER ACCELERATION IN VACUUM J.L. Hsu, T. Katsouleas

    E-Print Network [OSTI]

    Wurtele, Jonathan

    LASER ACCELERATION IN VACUUM J.L. Hsu, T. Katsouleas University of Southern California, Los Angeles electric fields of high-brightness lasers (e.g., up to order TV/cm) to accelerate particles. Unfortunately, as is well known, it is difficult to couple the vacuum field of the laser to particles so as to achieve a net

  20. Simple Laser Accelerator - Optics and Particle Dynamics 

    E-Print Network [OSTI]

    Scully, Marlan O.; Zubairy, M. Suhail.

    1991-01-01

    fitting structure are being investigated. The model developed will be presented to various Natural Gas producing countries such as Iran, Iraq, Russia, and Saudi to name a few and will ultimately be set up the same way that OPEC was....

  1. International Particle Accelerator Community Prepares for May...

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

    worldwide that serve as essential tools in disease diagnosis and treatment, in biomedical and materials research and in manufacturing, energy and security. More than 1,200...

  2. Fermilab | Science | Particle Accelerators | Advanced Superconducting Test

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photo feature photo

  3. How Particle Accelerators Work | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergy HeadquartersFuelB IMSofNewsletterGuidingUpdate Webinar Slidess g n i rFuel CellsHow

  4. Final Report: Particle Physics Research Program

    SciTech Connect (OSTI)

    Karchin, Paul E.

    2011-09-01

    We describe recent progress in accelerator-based experiments in high-energy particle physics and progress in theoretical investigations in particle physics. We also describe future plans in these areas.

  5. The BErkeley Lab Laser Accelerator (BELLA): A 10 GeV Laser Plasma Accelerator

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    of something like the proposed International Linear Collider--a 25 miles (40 kilometers) long machine place formidable demands on the accelerators that drive them. The design of the International Linear Collider (ILC), an RF-driven, TeV-scale, electron-positron machine, calls for a luminosity of 1034 cm-2 s-1

  6. The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part 1: Overview

    E-Print Network [OSTI]

    Billing, M G

    2015-01-01

    Cornell's electron/positron storage ring (CESR) was modified over a series of accelerator shutdowns beginning in May 2008, which substantially improves its capability for research and development for particle accelerators. CESR's energy span from 1.8 to 5.6 GeV with both electrons and positrons makes it ideal for the study of a wide spectrum of accelerator physics issues and instrumentation related to present light sources and future lepton damping rings. Additionally a number of these are also relevant for the beam physics of proton accelerators. This paper outlines the motivation, design and conversion of CESR to a test accelerator, CesrTA, enhanced to study such subjects as low emittance tuning methods, electron cloud (EC) effects, intra-beam scattering, fast ion instabilities as well as general improvements to beam instrumentation. While the initial studies of CesrTA focussed on questions related to the International Linear Collider (ILC) damping ring design, CesrTA is a very flexible storage ring, capabl...

  7. Exact analysis of particle dynamics in combined field of finite duration laser pulse and static axial magnetic field

    SciTech Connect (OSTI)

    Sagar, Vikram; Sengupta, Sudip; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2012-11-15

    Dynamics of a charged particle is studied in the field of a relativistically intense linearly polarized finite duration laser pulse in the presence of a static axial magnetic field. For a finite duration laser pulse whose temporal shape is defined by Gaussian profile, exact analytical expressions are derived for the particle trajectory, momentum, and energy as function of laser phase. From the solutions, it is shown that, unlike for the monochromatic plane wave case, resonant phase locking time between the particle and laser pulse is finite. The net energy transferred to the particle does not increase monotonically but tends to saturate. It is further shown that appropriate tuning of cyclotron frequency of the particle with the characteristic frequency in the pulse spectrum can lead to the generation of accelerated particles with variable energies in MeV-TeV range.

  8. Summary Report of Working Group 1: Laser-Plasma Acceleration

    SciTech Connect (OSTI)

    Geddes, C.G.R.; Clayton, C.; Lu, W.; Thomas, A.G.R.

    2010-06-01

    Advances in and physics of the acceleration of particles using underdense plasma structures driven by lasers were the topics of presentations and discussions in Working Group 1 of the 2010 Advanced Accelerator Concepts Workshop. Such accelerators have demonstrated gradients several orders beyond conventional machines, with quasi-monoenergetic beams at MeV-GeV energies, making them attractive candidates for next generation accelerators. Workshop discussions included advances in control over injection and laser propagation to further improve beam quality and stability, detailed diagnostics and physics models of the acceleration process, radiation generation as a source and diagnostic, and technological tools and upcoming facilities to extend the reach of laser-plasma accelerators.

  9. APT accelerator. Topical report

    SciTech Connect (OSTI)

    Lawrence, G.; Rusthoi, D.

    1995-03-01

    The Accelerator Production of Tritium (APT) project, sponsored by Department of Energy Defense Programs (DOE/DP), involves the preconceptual design of an accelerator system to produce tritium for the nation`s stockpile of nuclear weapons. Tritium is an isotope of hydrogen used in nuclear weapons, and must be replenished because of radioactive decay (its half-life is approximately 12 years). Because the annual production requirements for tritium has greatly decreased since the end of the Cold War, an alternative approach to reactors for tritium production, based on a linear accelerator, is now being seriously considered. The annual tritium requirement at the time this study was undertaken (1992-1993) was 3/8 that of the 1988 goal, usually stated as 3/8-Goal. Continued reduction in the number of weapons in the stockpile has led to a revised (lower) production requirement today (March, 1995). The production requirement needed to maintain the reduced stockpile, as stated in the recent Nuclear Posture Review (summer 1994) is approximately 3/16-Goal, half the previous level. The Nuclear Posture Review also requires that the production plant be designed to accomodate a production increase (surge) to 3/8-Goal capability within five years, to allow recovery from a possible extended outage of the tritium plant. A multi-laboratory team, collaborating with several industrial partners, has developed a preconceptual APT design for the 3/8-Goal, operating at 75% capacity. The team has presented APT as a promising alternative to the reactor concepts proposed for Complex-21. Given the requirements of a reduced weapons stockpile, APT offers both significant safety, environmental, and production-fexibility advantages in comparison with reactor systems, and the prospect of successful development in time to meet the US defense requirements of the 21st Century.

  10. Accelerator and electrodynamics capability review

    SciTech Connect (OSTI)

    Jones, Kevin W

    2010-01-01

    Los Alamos National Laboratory (LANL) uses capability reviews to assess the science, technology and engineering (STE) quality and institutional integration and to advise Laboratory Management on the current and future health of the STE. Capability reviews address the STE integration that LANL uses to meet mission requirements. The Capability Review Committees serve a dual role of providing assessment of the Laboratory's technical contributions and integration towards its missions and providing advice to Laboratory Management. The assessments and advice are documented in reports prepared by the Capability Review Committees that are delivered to the Director and to the Principal Associate Director for Science, Technology and Engineering (PADSTE). Laboratory Management will use this report for STE assessment and planning. LANL has defined fifteen STE capabilities. Electrodynamics and Accelerators is one of the seven STE capabilities that LANL Management (Director, PADSTE, technical Associate Directors) has identified for review in Fiscal Year (FY) 2010. Accelerators and electrodynamics at LANL comprise a blend of large-scale facilities and innovative small-scale research with a growing focus on national security applications. This review is organized into five topical areas: (1) Free Electron Lasers; (2) Linear Accelerator Science and Technology; (3) Advanced Electromagnetics; (4) Next Generation Accelerator Concepts; and (5) National Security Accelerator Applications. The focus is on innovative technology with an emphasis on applications relevant to Laboratory mission. The role of Laboratory Directed Research and Development (LDRD) in support of accelerators/electrodynamics will be discussed. The review provides an opportunity for interaction with early career staff. Program sponsors and customers will provide their input on the value of the accelerator and electrodynamics capability to the Laboratory mission.

  11. Chemical Accelerators The phrase "chemical accelerators"

    E-Print Network [OSTI]

    Meetings Chemical Accelerators The phrase "chemical accelerators" is scarcely older than for one or two dozen people grew to include nearly a hundred. Chemical accelerators is a name sug- gested by one of us for devices that produce beams of chemically interesting species at relative kinetic

  12. Compensation Techniques in Accelerator Physics

    SciTech Connect (OSTI)

    Hisham Kamal Sayed

    2011-05-31

    Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain, and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along with applying state of the art techniques in beam dynamics will be used in this dissertation to study and solve accelerator physics problems. Two problems involving compensation are studied in the context of the MEIC (Medium Energy Electron Ion Collider) project at Jefferson Laboratory. Several chromaticity (the energy dependence of the particle tune) compensation methods are evaluated numerically and deployed in a figure eight ring designed for the electrons in the collider. Furthermore, transverse coupling optics have been developed to compensate the coupling introduced by the spin rotators in the MEIC electron ring design.

  13. Basic non-linear effects in silicon radiation detector in detection of highly ionizing particles: registration of ultra rare events of superheavy nuclei in the long-term experiments

    E-Print Network [OSTI]

    Y. S. Tsyganov

    2015-06-08

    Sources of non-linear response of PIPS detector, when detecting highly ionizing particles like recoils (EVR), fission fragments and heavy ions, including formation of large pulse-height defect (PHD) are considered. An analytical formula to calculate the recombination component of EVR PHD is proposed on the base of surface recombination model with some empirical correction. PC-based simulation code for generating the spectrum of the measured recoil signal amplitudes of the heavy implanted nuclei is presented. The simulated spectra are compared with the experimental ones for the different facilities: the Dubna Gas Filled Recoil Separator (DGFRS), SHIP and RIKEN gas-filled separator. After the short reviewing of the detection system of the DGFRS, is considered the real-time matrix algorithm application aimed to the radical background suppression in the complete-fusion heavy-ion induced nuclear reactions. Typical examples of application in the long term experiments aimed to the synthesis of superheavy elements Z=112-118 are presented [1-9].

  14. ACCELERATING POLARIZED PROTONS TO HIGH ENERGY.

    SciTech Connect (OSTI)

    BAI, M.; AHRENS, L.; ALEKSEEV, I.G.; ALESSI, J.; BEEBE-WANG, J.; BLASKIEWICZ, M.; BRAVAR, A.; BRENNAN, J.M.; BRUNO, D.; BUNCE, G.; ET AL.

    2006-10-02

    The Relativistic Heavy Ion Collider (RHIC) is designed to provide collisions of high energy polarized protons for the quest of understanding the proton spin structure. Polarized proton collisions at a beam energy of 100 GeV have been achieved in RHIC since 2001. Recently, polarized proton beam was accelerated to 250 GeV in RHIC for the first time. Unlike accelerating unpolarized protons, the challenge for achieving high energy polarized protons is to fight the various mechanisms in an accelerator that can lead to partial or total polarization loss due to the interaction of the spin vector with the magnetic fields. We report on the progress of the RHIC polarized proton program. We also present the strategies of how to preserve the polarization through the entire acceleration chain, i.e. a 200 MeV linear accelerator, the Booster, the AGS and RHIC.

  15. Accelerating Polarized Protons to High Energy

    SciTech Connect (OSTI)

    Bai, M.; Ahrens, L.; Alekseev, I. G.; Alessi, J.; Beebe-Wang, J.; Blaskiewicz, M.; Bravar, A.; Brennan, J. M.; Bruno, D.; Bunce, G.; Butler, J.; Cameron, P.; Connolly, R.; Delong, J.; D'Ottavio, T.; Drees, A.; Fischer, W.; Ganetis, G.; Gardner, C.; Glenn, J.

    2007-06-13

    The Relativistic Heavy Ion Collider (RHIC) is designed to provide collisions of high energy polarized protons for the quest of understanding the proton spin structure. Polarized proton collisions at a beam energy of 100 GeV have been achieved in RHIC since 2001. Recently, polarized proton beam was accelerated to 250 GeV in RHIC for the first time. Unlike accelerating unpolarized protons, the challenge for achieving high energy polarized protons is to fight the various mechanisms in an accelerator that can lead to partial or total polarization loss due to the interaction of the spin vector with the magnetic fields. We report on the progress of the RHIC polarized proton program. We also present the strategies of how to preserve the polarization through the entire acceleration chain, i.e. a 200 MeV linear accelerator, the Booster, the AGS and RHIC.

  16. Frontiers of particle beam physics

    SciTech Connect (OSTI)

    Sessler, A.M.

    1989-11-01

    First, a review is given of various highly-developed techniques for particle handling which are, nevertheless, being vigorously advanced at the present time. These include soft superconductor radio frequency cavities, hard superconductor magnets, cooling rings for ions and anti-protons, and damping rings for electrons. Second, attention is focused upon novel devices for particle generation, acceleration, and focusing. These include relativistic klystrons and free electron laser power sources, binary power multipliers, photocathodes, switched-power linacs, plasma beat-wave accelerators, plasma wake-field accelerators, plasma lenses, plasma adiabatic focusers and plasma compensators. 12 refs.

  17. Linear Value Function Approximation Linear Models

    E-Print Network [OSTI]

    Parr, Ronald

    Linear Value Function Approximation and Linear Models Ronald Parr Duke University Joint work terminology · Various forms of linear value function approximation · Linear approximate model formulation #12;Outline · Introduce terminology · Various forms of linear value function approximation · Linear

  18. Detection of acceleration radiation in a Bose-Einstein condensate

    E-Print Network [OSTI]

    A. Retzker; J. I. Cirac; M. B. Plenio; B. Reznik

    2007-09-22

    We propose and study methods for detecting the Unruh effect in a Bose-Einstein condensate. The Bogoliubov vacuum of a Bose-Einstein condensate is used here to simulate a scalar field-theory, and accelerated atom dots or optical lattices as means for detecting phonon radiation due to acceleration effects. We study Unruh's effect for linear acceleration and circular acceleration. In particular, we study the dispersive effects of the Bogoliubov spectrum on the ideal case of exact thermalization. Our results suggest that Unruh's acceleration radiation can be tested using current accessible experimental methods.

  19. Laser driven ion accelerator

    DOE Patents [OSTI]

    Tajima, Toshiki

    2005-06-14

    A system and method of accelerating ions in an accelerator to optimize the energy produced by a light source. Several parameters may be controlled in constructing a target used in the accelerator system to adjust performance of the accelerator system. These parameters include the material, thickness, geometry and surface of the target.

  20. Laser driven ion accelerator

    DOE Patents [OSTI]

    Tajima, Toshiki

    2006-04-18

    A system and method of accelerating ions in an accelerator to optimize the energy produced by a light source. Several parameters may be controlled in constructing a target used in the accelerator system to adjust performance of the accelerator system. These parameters include the material, thickness, geometry and surface of the target.

  1. Superconducting Radiofrequency (SRF) Accelerator Cavities

    ScienceCinema (OSTI)

    Reece, Charlie

    2014-05-22

    Charlie Reece, an accelerator technology scientist, explains how superconducting radiofrequency accelerator cavities work.

  2. Beam Trajectory control of the future Compact LInear Collider beam

    E-Print Network [OSTI]

    Balik, G; Bolzon, B; Brunetti, L; Caron, B; Deleglise, G; Jeremie, A; Le Breton, R; Lottin, J; Pacquet, L

    2011-01-01

    The future Compact LInear Collider (CLIC) currently under design at CERN (European Organization for Nuclear Research) would create high-energy particle collisions between electrons and positrons, and provide a tool for scientists to address many of the most compelling questions about the fundamental nature of matter, energy, space and time. In accelerating structure, it is well-established that vibrations generated by the ground motion constitute the main limiting factors for reaching the luminosity of 10^34 cm-2s-1. Several methods have been proposed to counteract this phenomena and active vibration controls based on the integration of mechatronic systems into the machine structure is probably one of the most promising. This paper studies the strategy of the vibration suppression. Active vibration control methods, such as optimized parameter of a numerical compensator, adaptive algorithm with real time control are investigated and implemented in the simulation layout. The requirement couldn’t be achieved w...

  3. Acceleration Mechanics in Relativistic Shocks by the Weibel Instability

    E-Print Network [OSTI]

    K. -I. Nishikawa; P. E. Hardee; C. B. Hededal; G. J. Fishman

    2006-01-11

    Plasma instabilities (e.g., Buneman, Weibel and other two-stream instabilities) created in collisionless shocks may be responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated long-term particle acceleration associated with relativistic electron-ion or electron-positron jet fronts propagating into an unmagnetized ambient electron-ion or electron-positron plasma. These simulations have been performed with a longer simulation system than our previous simulations in order to investigate the nonlinear stage of the Weibel instability and its particle acceleration mechanism. The current channels generated by the Weibel instability are surrounded by toroidal magnetic fields and radial electric fields. This radial electric field is quasi stationary and accelerates particles which are then deflected by the magnetic field.

  4. Focusing particle concentrator with application to ultrafine particles

    DOE Patents [OSTI]

    Hering, Susanne; Lewis, Gregory; Spielman, Steven R.

    2013-06-11

    Technology is presented for the high efficiency concentration of fine and ultrafine airborne particles into a small fraction of the sampled airflow by condensational enlargement, aerodynamic focusing and flow separation. A nozzle concentrator structure including an acceleration nozzle with a flow extraction structure may be coupled to a containment vessel. The containment vessel may include a water condensation growth tube to facilitate the concentration of ultrafine particles. The containment vessel may further include a separate carrier flow introduced at the center of the sampled flow, upstream of the acceleration nozzle of the nozzle concentrator to facilitate the separation of particle and vapor constituents.

  5. Petawatt pulsed-power accelerator

    DOE Patents [OSTI]

    Stygar, William A. (Albuquerque, NM); Cuneo, Michael E. (Albuquerque, NM); Headley, Daniel I. (Albuquerque, NM); Ives, Harry C. (Albuquerque, NM); Ives, legal representative; Berry Cottrell (Albuquerque, NM); Leeper, Ramon J. (Albuquerque, NM); Mazarakis, Michael G. (Albuquerque, NM); Olson, Craig L. (Albuquerque, NM); Porter, John L. (Sandia Park, NM); Wagoner; Tim C. (Albuquerque, NM)

    2010-03-16

    A petawatt pulsed-power accelerator can be driven by various types of electrical-pulse generators, including conventional Marx generators and linear-transformer drivers. The pulsed-power accelerator can be configured to drive an electrical load from one- or two-sides. Various types of loads can be driven; for example, the accelerator can be used to drive a high-current z-pinch load. When driven by slow-pulse generators (e.g., conventional Marx generators), the accelerator comprises an oil section comprising at least one pulse-generator level having a plurality of pulse generators; a water section comprising a pulse-forming circuit for each pulse generator and a level of monolithic triplate radial-transmission-line impedance transformers, that have variable impedance profiles, for each pulse-generator level; and a vacuum section comprising triplate magnetically insulated transmission lines that feed an electrical load. When driven by LTD generators or other fast-pulse generators, the need for the pulse-forming circuits in the water section can be eliminated.

  6. Laser-PlasmaWakefield Acceleration with Higher Order Laser Modes

    E-Print Network [OSTI]

    Geddes, C.G.R.

    2011-01-01

    Design considerations for a laser-plasma linear collider,"E.Esarey, and W.P.Leemans, "Free-electron laser driven bythe LBNL laser-plasma accelerator," in Proc. Adv. Acc. Con.

  7. Proceedings of the first international workshop on accelerator alignment

    SciTech Connect (OSTI)

    Not Available

    1990-10-01

    This report contains papers on the following accelerator topics: current alignment topics; toolboxes: instrumentation, software, and methods; fiducialization of conventional magnets; fiducialization of superconducting magnets; and next generation linear colliders.

  8. Experimental Plans to Explore Dielectric Wakefield Acceleration in the THZ Regime

    SciTech Connect (OSTI)

    Lemery, F.; Mihalcea, D.; /Northern Illinois U.; Piot, P.; /Fermilab; Behrens, C.; Elsen, E.; Flottmann, K.; Gerth, C.; Kube, G.; Schmidt, B.; /DESY; Osterhoff, J.; /Hamburg U., Inst. Theor. Phys. II; Stoltz, P.

    2011-09-07

    Dielectric wakefield accelerators have shown great promise toward high-gradient acceleration. We investigate the performances of a possible experiment under consideration at the FLASH facility in DESY to explore wakefield acceleration with an enhanced transformer ratio. The experiment capitalizes on a unique pulse shaping capability recently demonstrated at this facility. In addition, the facility incorporates a superconducting linear accelerator that could generate bunch trains with closely spaced bunches thereby opening the exploration of potential dynamical effects in dielectric wakefield accelerators.

  9. The effect of stochastic re-acceleration on the energy spectrum of shock-accelerated protons

    SciTech Connect (OSTI)

    Afanasiev, Alexandr; Vainio, Rami [Department of Physics, University of Helsinki, P.O. Box 64, Helsinki FI-00014 (Finland); Kocharov, Leon [Sodankylä Geophysical Observatory (Oulu Unit), University of Oulu, Oulu FI-90014 (Finland)

    2014-07-20

    The energy spectra of particles in gradual solar energetic particle (SEP) events do not always have a power-law form attributed to the diffusive shock acceleration mechanism. In particular, the observed spectra in major SEP events can take the form of a broken (double) power law. In this paper, we study the effect of a process that can modify the power-law spectral form produced by the diffusive shock acceleration: the stochastic re-acceleration of energetic protons by enhanced Alfvénic turbulence in the downstream region of a shock wave. There are arguments suggesting that this process can be important when the shock propagates in the corona. We consider a coronal magnetic loop traversed by a shock and perform Monte Carlo simulations of interactions of shock-accelerated protons with Alfvén waves in the loop. The wave-particle interactions are treated self-consistently, so the finiteness of the available turbulent energy is taken into account. The initial energy spectrum of particles is taken to be a power law. The simulations reveal that the stochastic re-acceleration leads either to the formation of a spectrum that is described in a wide energy range by a power law (although the resulting power-law index is different from the initial one) or to a broken power-law spectrum. The resulting spectral form is determined by the ratio of the energy density of shock-accelerated protons to the wave energy density in the shock's downstream region.

  10. Report of the Snowmass T4 working group on particle sources: Positron sources, anti-proton sources and secondary beams

    SciTech Connect (OSTI)

    N. Mokhov et al.

    2002-12-05

    This report documents the activities of the Snowmass 2001 T4 Particle Sources Working Group. T4 was charged with examining the most challenging aspects of positron sources for linear colliders and antiproton sources for proton-antiproton colliders, and the secondary beams of interest to the physics community that will be available from the next generation of high-energy particle accelerators. The leading issues, limiting technologies, and most important R and D efforts of positron production, antiproton production, and secondary beams are discussed in this paper. A listing of T4 Presentations is included.

  11. The Acceleration Mechanism of Resistive MHD Jets Launched from Accretion Disks

    E-Print Network [OSTI]

    T. Kuwabara; K. Shibata; T. Kudoh; R. Matsumoto

    2004-11-26

    We analyzed the results of non-linear resistive magnetohydrodynamical (MHD) simulations of jet formation to study the acceleration mechanism of axisymmetric, resistive MHD jets. The initial state is a constant angular momentum, polytropic torus threaded by weak uniform vertical magnetic fields. The time evolution of the torus is simulated by applying the CIP-MOCCT scheme extended for resistive MHD equations. We carried out simulations up to 50 rotation period at the innermost radius of the disk created by accretion from the torus. The acceleration forces and the characteristics of resistive jets were studied by computing forces acting on Lagrangian test particles. Since the angle between the rotation axis of the disk and magnetic field lines is smaller in resistive models than in ideal MHD models, magnetocentrifugal acceleration is smaller. The effective potential along a magnetic field line has maximum around $z \\sim 0.5r_0$ in resistive models, where $r_0$ is the radius where the density of the initial torus is maximum. Jets are launched after the disk material is lifted to this height by pressure gradient force. Even in this case, the main acceleration force around the slow magnetosonic point is the magnetocentrifugal force. The power of the resistive MHD jet is comparable to the mechanical energy liberated in the disk by mass accretion. Joule heating is not essential for the formation of jets.

  12. Simulation Study of Laser Plasma Accelerator Via Vorpal

    E-Print Network [OSTI]

    Zhu, Xiongwei

    2015-01-01

    In this paper, we use PIC code Vorpal to do the extensive simulation about the laser plasma accelerator in the linear, quasilinear and nonlinear regime respectively. We design the ~100 MeV or so laser plasma accelerator ( LPA ) via Vorpal simulation. Finally, we discuss the application of the designed LPA in the compact light source field.

  13. Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m

    ScienceCinema (OSTI)

    None

    2013-05-28

    Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m is a linear electron accelerator-based technology for producing medical imaging radioisotopes from a separation process that heats, vaporizes and condenses the desired radioisotope. You can learn more about INL's education programs at http://www.facebook.com/idahonationallaboratory.

  14. The Christie Proton Beam Therapy Centre! and Accelerator Research!

    E-Print Network [OSTI]

    ,000 patients a year ­ 14,000 new patients · Dedicated oncology focus · 16 networked linear accelerators to the service, with limited travel times by car or public transport! · Both sites at the centre of regional compact carbon accelerators ­ carbon-11 facility?! ­ Higher-energy, eco

  15. Acceleration Rates and Injection Efficiencies in Oblique Shocks

    E-Print Network [OSTI]

    D. C. Ellison; M. G. Baring; F. C. Jones

    1995-06-12

    The rate at which particles are accelerated by the first-order Fermi mechanism in shocks depends on the angle, \\teq{\\Tbone}, that the upstream magnetic field makes with the shock normal. The greater the obliquity the greater the rate, and in quasi-perpendicular shocks rates can be hundreds of times higher than those seen in parallel shocks. In many circumstances pertaining to evolving shocks (\\eg, supernova blast waves and interplanetary traveling shocks), high acceleration rates imply high maximum particle energies and obliquity effects may have important astrophysical consequences. However, as is demonstrated here, the efficiency for injecting thermal particles into the acceleration mechanism also depends strongly on obliquity and, in general, varies inversely with \\teq{\\Tbone}. The degree of turbulence and the resulting cross-field diffusion strongly influences both injection efficiency and acceleration rates. The test particle \\mc simulation of shock acceleration used here assumes large-angle scattering, computes particle orbits exactly in shocked, laminar, non-relativistic flows, and calculates the injection efficiency as a function of obliquity, Mach number, and degree of turbulence. We find that turbulence must be quite strong for high Mach number, highly oblique shocks to inject significant numbers of thermal particles and that only modest gains in acceleration rates can be expected for strong oblique shocks over parallel ones if the only source of seed particles is the thermal background.

  16. Direct laser acceleration of electrons in free-space

    E-Print Network [OSTI]

    Carbajo, Sergio; Wong, Liang Jie; Miller, R J Dwayne; Kärtner, Franz X

    2015-01-01

    Compact laser-driven accelerators are versatile and powerful tools of unarguable relevance on societal grounds for the diverse purposes of science, health, security, and technology because they bring enormous practicality to state-of-the-art achievements of conventional radio-frequency accelerators. Current benchmarking laser-based technologies rely on a medium to assist the light-matter interaction, which impose material limitations or strongly inhomogeneous fields. The advent of few cycle ultra-intense radially polarized lasers has materialized an extensively studied novel accelerator that adopts the simplest form of laser acceleration and is unique in requiring no medium to achieve strong longitudinal energy transfer directly from laser to particle. Here we present the first observation of direct longitudinal laser acceleration of non-relativistic electrons that undergo highly-directional multi-GeV/m accelerating gradients. This demonstration opens a new frontier for direct laser-driven particle accelerati...

  17. Fermi National Accelerator Laboratory August 2015 The NO?A Neutrino...

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

    scientists determine the role that ghostly particles called neutrinos played in the evolution of the cosmos. The world's best neutrino beam Fermilab's accelerator complex...

  18. Core of First Section of New Accelerator Rolled Out | Jefferson...

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

    and rolled out for further assembly. This "string" of components will become the heart of a cryomodule, which will be added to the lab's particle accelerator in 2012. Core...

  19. Use of dielectric material in muon accelerator RF cavities

    E-Print Network [OSTI]

    French, Katheryn Decker

    2011-01-01

    The building of a muon collider is motivated by the desire to collide point-like particles while reducing the limitations imposed by synchrotron radiation. The many challenges unique to muon accelerators are derived from ...

  20. Testing General Relativity With Laser Accelerated Electron Beams

    E-Print Network [OSTI]

    L. Á. Gergely; T. Harko

    2012-07-16

    Electron accelerations of the order of $10^{21} g$ obtained by laser fields open up the possibility of experimentally testing one of the cornerstones of general relativity, the weak equivalence principle, which states that the local effects of a gravitational field are indistinguishable from those sensed by a properly accelerated observer in flat space-time. We illustrate how this can be done by solving the Einstein equations in vacuum and integrating the geodesic equations of motion for a uniformly accelerated particle.

  1. Multifractal statistics of Lagrangian velocity and acceleration in turbulence

    E-Print Network [OSTI]

    L. Biferale; G. Boffetta; A. Celani; B. J. Devenish; A. Lanotte; F. Toschi

    2004-03-11

    The statistical properties of velocity and acceleration fields along the trajectories of fluid particles transported by a fully developed turbulent flow are investigated by means of high resolution direct numerical simulations. We present results for Lagrangian velocity structure functions, the acceleration probability density function and the acceleration variance conditioned on the instantaneous velocity. These are compared with predictions of the multifractal formalism and its merits and limitations are discussed.

  2. Photo of the Week: What Do Airborne Radioactive Particles Taste...

    Broader source: Energy.gov (indexed) [DOE]

    could be widely used in medicine and industry -- particle accelerators are used for cancer research, processing computer chips, and even producing the shrink wrap used to keep...

  3. Jefferson Lab Fall Lecture: Exploring Our World With Particle...

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

    Nov. 23, with James E. Brau, University of Oregon, presenting "The Mysterious Universe: Exploring Our World with Particle Accelerators." The universe is dark and...

  4. Accelerator Development @ Daresbury Laboratory

    E-Print Network [OSTI]

    -injectors ­ Superconducting RF acceleration ­ Cryogenic systems ­ Advanced diagnostics ­ Free Electron Lasers ­ Photon beam radioisotopes. 2 Treatment & Diagnostics #12;Basic Accelerator Configuration 3 Beam Source Low Energy Capture electron beam technology development. 4 Booster Compressor IR-FEL Photoinjector Laser Linac Acceleration

  5. Relativistic electron acceleration by oblique whistler waves

    SciTech Connect (OSTI)

    Yoon, Peter H.; School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 ; Pandey, Vinay S.; Lee, Dong-Hun

    2013-11-15

    Test-particle simulations of electrons interacting with finite-amplitude, obliquely propagating whistler waves are carried out in order to investigate the acceleration of relativistic electrons by these waves. According to the present findings, an efficient acceleration of relativistic electrons requires a narrow range of oblique propagation angles, close to the whistler resonance cone angle, when the wave amplitude is held constant at relatively low value. For a constant wave propagation angle, it is found that a range of oblique whistler wave amplitudes permits the acceleration of relativistic electrons to O(MeV) energies. An initial distribution of test electrons is shown to form a power-law distribution when plotted in energy space. It is also found that the acceleration is largely uniform in electron pitch-angle space.

  6. 252 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 24, NO. 2, APRIL 1996 Overview of Plasma-Based Accelerator Concepts

    E-Print Network [OSTI]

    Geddes, Cameron Guy Robinson

    , and wakefield accelerators driven by multiple electron or laser pulses. Basic properties of linear and nonlinear laser systems based on the technique of chirped-pulse amplification [lo]-[ 171. Electron acceleration

  7. PUBLISHED ONLINE: 6 OCTOBER 2013 | DOI: 10.1038/NPHYS2767 Quasiperiodic acceleration of electrons by a

    E-Print Network [OSTI]

    Loss, Daniel

    that plasmoid-driven quasiperpendicular shocks are capable of producing quasiperiodic acceleration of electrons System and are often associated with plasma shocks and the acceleration of particles to relativistic, and that the radio bursts, generated by accelerated particles, result from this same wave/shock system

  8. Cosmic-ray acceleration in supernova shocks

    E-Print Network [OSTI]

    Vincent Tatischeff

    2008-07-25

    Galactic cosmic rays are widely believed to be accelerated in expanding shock waves initiated by supernova explosions. The theory of diffusive shock acceleration of cosmic rays is now well established, but two fundamental questions remain partly unanswered: what is the acceleration efficiency, i.e. the fraction of the total supernova energy converted to cosmic-ray energy, and what is the maximum kinetic energy achieved by particles accelerated in supernova explosions? Recent observations of supernova remnants, in X-rays with the Chandra and XMM-Newton satellites and in very-high-energy gamma rays with several ground-based atmospheric Cerenkov telescopes, have provided new pieces of information concerning these two questions. After a review of these observations and their current interpretations, I show that complementary information on the diffusive shock acceleration process can be obtained by studying the radio emission from extragalactic supernovae. As an illustration, a nonlinear model of diffusive shock acceleration is applied to the radio light curves of the supernova SN 1993J, which exploded in the nearby galaxy M81. The results of the model suggest that most of the Galactic cosmic rays may be accelerated during the early phase of interaction between the supernova ejecta and the wind lost from the progenitor star.

  9. Physics Case for the International Linear Collider

    E-Print Network [OSTI]

    Keisuke Fujii; Christophe Grojean; Michael E. Peskin; Tim Barklow; Yuanning Gao; Shinya Kanemura; Hyungdo Kim; Jenny List; Mihoko Nojiri; Maxim Perelstein; Roman Poeschl; Juergen Reuter; Frank Simon; Tomohiko Tanabe; Jaehoon Yu; James D. Wells; Hitoshi Murayama; Hitoshi Yamamoto

    2015-06-26

    We summarize the physics case for the International Linear Collider (ILC). We review the key motivations for the ILC presented in the literature, updating the projected measurement uncertainties for the ILC experiments in accord with the expected schedule of operation of the accelerator and the results of the most recent simulation studies.

  10. Physics Case for the International Linear Collider

    E-Print Network [OSTI]

    Fujii, Keisuke; Peskin, Michael E; Barklow, Tim; Gao, Yuanning; Kanemura, Shinya; Kim, Hyungdo; List, Jenny; Nojiri, Mihoko; Perelstein, Maxim; Poeschl, Roman; Reuter, Juergen; Simon, Frank; Tanabe, Tomohiko; Yu, Jaehoon; Wells, James D; Murayama, Hitoshi; Yamamoto, Hitoshi

    2015-01-01

    We summarize the physics case for the International Linear Collider (ILC). We review the key motivations for the ILC presented in the literature, updating the projected measurement uncertainties for the ILC experiments in accord with the expected schedule of operation of the accelerator and the results of the most recent simulation studies.

  11. Analytical tools in accelerator physics

    SciTech Connect (OSTI)

    Litvinenko, V.N.

    2010-09-01

    This paper is a sub-set of my lectures presented in the Accelerator Physics course (USPAS, Santa Rosa, California, January 14-25, 2008). It is based on my notes I wrote during period from 1976 to 1979 in Novosibirsk. Only few copies (in Russian) were distributed to my colleagues in Novosibirsk Institute of Nuclear Physics. The goal of these notes is a complete description starting from the arbitrary reference orbit, explicit expressions for 4-potential and accelerator Hamiltonian and finishing with parameterization with action and angle variables. To a large degree follow logic developed in Theory of Cyclic Particle Accelerators by A.A.Kolmensky and A.N.Lebedev [Kolomensky], but going beyond the book in a number of directions. One of unusual feature is these notes use of matrix function and Sylvester formula for calculating matrices of arbitrary elements. Teaching the USPAS course motivated me to translate significant part of my notes into the English. I also included some introductory materials following Classical Theory of Fields by L.D. Landau and E.M. Liftsitz [Landau]. A large number of short notes covering various techniques are placed in the Appendices.

  12. Acceleration and Parallax Effects in Gravitational Microlensing

    E-Print Network [OSTI]

    M. C. Smith; S. Mao; B. Paczynski

    2003-01-27

    To generate the standard microlensing light curve one assumes that the relative motion of the source, the lens, and the observer is linear. In reality, the relative motion is likely to be more complicated due to accelerations of the observer, the lens and the source. The simplest approximation beyond the linear-motion assumption is to add a constant acceleration. Microlensing light curves due to accelerations can be symmetric or asymmetric depending on the angle between the acceleration and the velocity. We show that it is possible that some of the previously reported shorter marginal parallax events can be reproduced with constant-acceleration models, while the longer, multi-year parallax events are ill-fitted by such models. We find that there is a generic degeneracy inherent in constant-acceleration microlensing models. We also find that there is an equivalent degeneracy in parallax models, which manifests itself in short-duration events. The importance of this new parallax degeneracy is illustrated with an example, using one of these marginal parallax events. Our new analysis suggests that another of these previously suspected parallax candidate events may be exhibiting some weak binary-source signatures. If this turns out to be true, spectroscopic observations of the source could determine some parameters in the model and may also constrain or even determine the lens mass. We also point out that symmetric light curves with constant accelerations can mimic blended light curves, producing misleading Einstein-radius crossing time-scales when fitted by the standard `blended' microlensing model; this may have some effect on the estimation of optical depth.

  13. Elementary particle interactions

    SciTech Connect (OSTI)

    Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Ward, B.F.L.; Close, F.E.; Christophorou, L.G.

    1990-10-01

    This report discusses freon bubble chamber experiments exposed to {mu}{sup +} and neutrinos, photon-proton interactions; shower counter simulations; SLD detectors at the Stanford Linear Collider, and the detectors at the Superconducting Super Collider; elementary particle interactions; physical properties of dielectric materials used in High Energy Physics detectors; and Nuclear Physics. (LSP)

  14. Testing general relativity on accelerators

    E-Print Network [OSTI]

    Tigran Kalaydzhyan

    2015-09-09

    Within the general theory of relativity, the curvature of spacetime is related to the energy and momentum of the present matter and radiation. One of the more specific predictions of general relativity is the deflection of light and particle trajectories in the gravitational field of massive objects. Bending angles for electromagnetic waves and light in particular were measured with a high precision. However, the effect of gravity on relativistic massive particles was never studied experimentally. Here we propose and analyze experiments devoted to that purpose. We demonstrate a high sensitivity of the laser Compton scattering at high energy accelerators to the effects of gravity. The main observable -- maximal energy of the scattered photons -- would experience a significant shift in the ambient gravitational field even for otherwise negligible violation of the equivalence principle. We confirm predictions of general relativity for ultrarelativistic electrons of energy of tens of GeV at a current level of resolution and expect our work to be a starting point of further high-precision studies on current and future accelerators, such as PETRA, European XFEL and ILC.

  15. Status report on the "Merging" of the Electron-Cloud Code POSINST withthe 3-D Accelerator PIC CODE WARP

    E-Print Network [OSTI]

    2004-01-01

    WARP3d, a Three-Dimensional PIC/Accelerator Code", Proc. ofWITH THE 3-D ACCELERATOR PIC CODE WARP * J. -L. Vay # , M.combine the particle-in-cell (PIC) technique commonly used

  16. Plasma Wakefield Acceleration for Ultrahigh Energy Cosmic Rays

    E-Print Network [OSTI]

    Pisin Chen; Toshiki Tajima; Yoshiyuki Takahashi

    2002-05-21

    A cosmic acceleration mechanism is introduced which is based on the wakefields excited by the Alfven shocks in a relativistically flowing plasma, where the energy gain per distance of a test particle is Lorentz invariant. We show that there exists a threshold condition for transparency below which the accelerating particle is collision-free and suffers little energy loss in the plasma medium. The stochastic encounters of the random accelerating-decelerating phases results in a power-law energy spectrum: f(e) 1/e^2. The environment suitable for such plasma wakefield acceleration can be cosmically abundant. As an example, we discuss the possible production of super-GZK ultra high energy cosmic rays (UHECR) through this mechanism in the atmosphere of gamma ray bursts. We show that the acceleration gradient can be as high as G ~ 10^16 eV/cm. The estimated event rate in our model agrees with that from UHECR observations.

  17. Unruh versus Tolman: On the heat of acceleration

    E-Print Network [OSTI]

    Buchholz, Detlev

    2015-01-01

    It is shown that the Unruh effect, i.e. the increase in temperature indicated by a uniformly accelerated thermometer in an inertial vacuum state of a quantum field, cannot be interpreted as the result of an exchange of heat with a surrounding gas of particles. Since the vacuum is spatially homogeneous in any accelerated system its temperature must be zero everywhere as a consequence of Tolman's law. In fact, the increase of temperature of accelerated thermometers is due to systematic quantum effects induced by the local coupling between the thermometer and the vacuum. This coupling inevitably creates particles from the vacuum which transfer energy to the thermometer, gained by the acceleration, and thereby affect its readings. The temperature of the vacuum, however, remains to be zero for arbitrary accelerations.

  18. Unruh versus Tolman: On the heat of acceleration

    E-Print Network [OSTI]

    Detlev Buchholz; Rainer Verch

    2015-05-07

    It is shown that the Unruh effect, i.e. the increase in temperature indicated by a uniformly accelerated thermometer in an inertial vacuum state of a quantum field, cannot be interpreted as the result of an exchange of heat with a surrounding gas of particles. Since the vacuum is spatially homogeneous in any accelerated system its temperature must be zero everywhere as a consequence of Tolman's law. In fact, the increase of temperature of accelerated thermometers is due to systematic quantum effects induced by the local coupling between the thermometer and the vacuum. This coupling inevitably creates particles from the vacuum which transfer energy to the thermometer, gained by the acceleration, and thereby affect its readings. The temperature of the vacuum, however, remains to be zero for arbitrary accelerations.

  19. Characterization of Fundamental Particles

    E-Print Network [OSTI]

    Ben J Baten

    2009-05-25

    This report provides an alternative to the Standard Model of particle physics. The model described here is based on results from Quantum Field Mechanics, according to which all fundamental particles and interactions originate from the interaction of two pre-space/pre-time protofields. In contrast with the Standard Model, (virtual) interaction-particles are absent in the description of any of the four fundamental interactions. Electrons perform a single quantum beat process while mesons and baryons have, respectively, two and three bound quantum beat processes. Quantum Field Mechanics suggests that the charge of an electron and positron can be identified with the two possible phases of a quantum beat process as observed in the electromagnetic protofield. This report assumes that short-range binding interaction between quantum beat processes has a masking effect on the externally observable charge of hadrons. Using this assumption, the internal structure of particles is derived from their known particle charges and relative masses. The particle structures are used to obtain the so-called charge-quantum phase law. The fractional charge of quantum beat processes inside a particle is deduced by rewriting the charge-quantum phase law in terms of a linear combination of charge contributions of individual constituent quantum beat processes. Strangeness and isospin are mathematically defined in terms of the quantum beat phases of sets of particles of the same type. Application of conservation laws to particle processes leads to relations between quantum phase, strangeness and isospin.

  20. Optically pulsed electron accelerator

    DOE Patents [OSTI]

    Fraser, J.S.; Sheffield, R.L.

    1985-05-20

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  1. Optically pulsed electron accelerator

    DOE Patents [OSTI]

    Fraser, John S. (Los Alamos, NM); Sheffield, Richard L. (Los Alamos, NM)

    1987-01-01

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  2. Ion Acceleration by Short Chirped Laser Pulses

    E-Print Network [OSTI]

    Li, Jian-Xing; Keitel, Christoph H; Harman, Zoltán

    2015-01-01

    Direct laser acceleration of ions by short frequency-chirped laser pulses is investigated theoretically. We demonstrate that intense beams of ions with a kinetic energy broadening of about 1 % can be generated. The chirping of the laser pulse allows the particles to gain kinetic energies of hundreds of MeVs, which is required for hadron cancer therapy, from pulses of energies of the order of 100 J. It is shown that few-cycle chirped pulses can accelerate ions more efficiently than long ones, i.e. higher ion kinetic energies are reached with the same amount of total electromagnetic pulse energy.

  3. Memristive Accelerator for Extreme Scale Linear Solvers Isaac Richter1

    E-Print Network [OSTI]

    Friedman, Eby G.

    , Ravi Patel1 , Ji Liu2 , Engin Ipek1,2 , and Eby G. Friedman1 1 Department of Electrical and Computer scientific and engineering research and development. Large scale computational models of the Earth's weather- cessive over-relaxation, or adaptive multi-grid. These itera- tive solvers first estimate the solution

  4. Beamstrahlung considerations in laser-plasma-accelerator-based linear colliders

    E-Print Network [OSTI]

    Schroeder, Carl

    2013-01-01

    1/2 ? ?2 n 1/2 Total AC power, P wall laser to the beam ? Lpn 3/4 n 1/2 Total AC power, P wall n ?1 n ?1/2 n ?1/4 Bunchbeam) [%] Total wall-plug power, P wall [GW] Energy, center-

  5. DOE - Office of Legacy Management -- Stanford Linear Accelerator Center -

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouth DakotaRobbins and Myers Co - OH

  6. Fourth order resonance of a high intensity linear accelerator* (Journal

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article) |production atmeasurementComparisonArticle)sNN=5.02

  7. 2010 Annual Planning Summary for Stanford Linear Accelerator Center Site

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p a l De p u t y A s s i s t a n tAttachment: Memo, AllisonPlanOffice

  8. Accelerating Majorization Algorithms

    E-Print Network [OSTI]

    Jan de Leeuw

    2011-01-01

    incomplete data via the em algorithm. Journal of the RoyalACCELERATING MAJORIZATION ALGORITHMS JAN DE LEEUW Abstract.construc- tion of majorization algorithms and their rate of

  9. Accelerating Majorization Algorithms

    E-Print Network [OSTI]

    Leeuw, Jan de

    2008-01-01

    incomplete data via the em algorithm. Journal of the RoyalACCELERATING MAJORIZATION ALGORITHMS JAN DE LEEUW Abstract.construc- tion of majorization algorithms and their rate of

  10. Market Acceleration (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2010-09-01

    The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts within its market acceleration subprogram.

  11. Lab announces Venture Acceleration

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

    a 3D virtualization company, enabling the use of 3D virtualization in art and cultural preservation markets. LAVA Chief Operations Officer Steve Smith said the "acceleration"...

  12. Charged fermions tunneling from accelerating and rotating black holes

    SciTech Connect (OSTI)

    Rehman, Mudassar; Saifullah, K., E-mail: mudassir051@yahoo.com, E-mail: saifullah@qau.edu.pk [Department of Mathematics, Quaid-i-Azam University, Islamabad (Pakistan)

    2011-03-01

    We study Hawking radiation of charged fermions from accelerating and rotating black holes with electric and magnetic charges. We calculate the tunneling probabilities of incoming and outgoing fermionic particles and find the Hawking temperature of these black holes. We also provide an explicit expression of the classical action for the massive and massless particles in the background of these black holes.

  13. Field Emission in CEBAF's SRF Cavities and Implications for Future Accelerators

    SciTech Connect (OSTI)

    Jay Benesch

    2006-02-15

    Field emission is one of the key issues in superconducting RF for particle accelerators. When present, it limits operating gradient directly or via induced heat load at 2K. In order to minimize particulate contamination of and thus field emission in the CEBAF SRF cavities during assembly, a cold ceramic RF window was placed very close to the accelerating cavity proper. As an unintended consequence of this, the window is charged by field-emitted electrons, making it possible to monitor and model field emission in the CEBAF cavities since in-tunnel operation began. From January 30, 1995, through February 10, 2003, there were 64 instances of spontaneous onset or change in cavity field emission with a drop in usable gradient averaging 1.4 ({sigma} 0.8) MV/m at each event. Fractional loss averaged 0.18 ({sigma} 0.12) of pre-event gradient. This event count corresponds to 2.4 events per century per cavity, or 8 per year in CEBAF. It is hypothesized that changes in field emission are due to adsorbed gas accumulation. The possible implications of this and other observations for the International Linear Collider (ILC) and other future accelerators will be discussed.

  14. Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams

    SciTech Connect (OSTI)

    Siemann, R.H.; /SLAC

    2011-10-24

    Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

  15. Confined energy distribution for charged particle beams

    DOE Patents [OSTI]

    Jason, Andrew J. (Los Alamos, NM); Blind, Barbara (Los Alamos, NM)

    1990-01-01

    A charged particle beam is formed to a relatively larger area beam which is well-contained and has a beam area which relatively uniformly deposits energy over a beam target. Linear optics receive an accelerator beam and output a first beam with a first waist defined by a relatively small size in a first dimension normal to a second dimension. Nonlinear optics, such as an octupole magnet, are located about the first waist and output a second beam having a phase-space distribution which folds the beam edges along the second dimension toward the beam core to develop a well-contained beam and a relatively uniform particle intensity across the beam core. The beam may then be expanded along the second dimension to form the uniform ribbon beam at a selected distance from the nonlinear optics. Alternately, the beam may be passed through a second set of nonlinear optics to fold the beam edges in the first dimension. The beam may then be uniformly expanded along the first and second dimensions to form a well-contained, two-dimensional beam for illuminating a two-dimensional target with a relatively uniform energy deposition.

  16. Slow wave structures using twisted waveguides for charged particle applications

    DOE Patents [OSTI]

    Kang, Yoon W.; Fathy, Aly E.; Wilson, Joshua L.

    2012-12-11

    A rapidly twisted electromagnetic accelerating structure includes a waveguide body having a central axis, one or more helical channels defined by the body and disposed around a substantially linear central axial channel, with central portions of the helical channels merging with the linear central axial channel. The structure propagates electromagnetic waves in the helical channels which support particle beam acceleration in the central axial channel at a phase velocity equal to or slower than the speed of light in free space. Since there is no variation in the shape of the transversal cross-section along the axis of the structure, inexpensive mechanical fabrication processes can be used to form the structure, such as extrusion, casting or injection molding. Also, because the field and frequency of the resonant mode depend on the whole structure rather than on dimensional tolerances of individual cells, no tuning of individual cells is needed. Accordingly, the overall operating frequency may be varied with a tuning/phase shifting device located outside the resonant waveguide structure.

  17. Accelerators (5/5)

    SciTech Connect (OSTI)

    2009-07-09

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  18. Accelerators (4/5)

    SciTech Connect (OSTI)

    2009-07-08

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  19. Accelerators (3/5)

    SciTech Connect (OSTI)

    2009-07-07

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  20. Accelerators (3/5)

    ScienceCinema (OSTI)

    None

    2011-10-06

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  1. Accelerators (4/5)

    ScienceCinema (OSTI)

    None

    2011-10-06

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  2. Microscale acceleration history discriminators

    DOE Patents [OSTI]

    Polosky, Marc A. (Albuquerque, NM); Plummer, David W. (Albuquerque, NM)

    2002-01-01

    A new class of micromechanical acceleration history discriminators is claimed. These discriminators allow the precise differentiation of a wide range of acceleration-time histories, thereby allowing adaptive events to be triggered in response to the severity (or lack thereof) of an external environment. Such devices have applications in airbag activation, and other safety and surety applications.

  3. Accelerators (5/5)

    ScienceCinema (OSTI)

    None

    2011-10-06

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  4. Safety of Accelerator Facilities

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

    2004-07-23

    To establish accelerator-specific safety requirements which, when supplemented by other applicable safety and health requirements, will serve to prevent injuries and illnesses associated with Department of Energy (DOE) or National Nuclear Security Administration (NNSA) accelerator operations. Cancels DOE O 420.2A. Certified 5-13-08. Canceled by DOE O 420.2C.

  5. Safety of Accelerator Facilities

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

    2011-07-21

    The order defines accelerators and establishes accelerator specific safety requirements and approval authorities which, when supplemented by other applicable safety and health requirements, promote safe operations to ensure protection of workers, the public, and the environment. Supersedes DOE O 420.2B.

  6. Safety of Accelerator Facilities

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

    2001-01-08

    To establish accelerator-specific safety requirements which, when supplemented by other applicable safety and health requirements, will serve to prevent injuries and illnesses associated with Department of Energy (DOE) or National Nuclear Security Administration (NNSA) accelerator operations. Cancels DOE O 420.2. Canceled by DOE O 420.2B.

  7. The Microscopic Linear Dynamics

    E-Print Network [OSTI]

    Penny, Will

    The Microscopic Brain Will Penny Linear Dynamics Exponentials Matrix Exponential Eigendecomposition References The Microscopic Brain Will Penny 7th April 2011 #12;The Microscopic Brain Will Penny Linear;The Microscopic Brain Will Penny Linear Dynamics Exponentials Matrix Exponential Eigendecomposition

  8. Radio Frequency Station - Beam Dynamics Interaction in Circular Accelerators

    SciTech Connect (OSTI)

    Mastoridis, Themistoklis; /Stanford U., Elect. Eng. Dept. /SLAC

    2011-03-01

    The longitudinal beam dynamics in circular accelerators is mainly defined by the interaction of the beam current with the accelerating Radio Frequency (RF) stations. For stable operation, Low Level RF (LLRF) feedback systems are employed to reduce coherent instabilities and regulate the accelerating voltage. The LLRF system design has implications for the dynamics and stability of the closed-loop RF systems as well as for the particle beam, and is very sensitive to the operating range of accelerator currents and energies. Stability of the RF loop and the beam are necessary conditions for reliable machine operation. This dissertation describes theoretical formalisms and models that determine the longitudinal beam dynamics based on the LLRF implementation, time domain simulations that capture the dynamic behavior of the RF station-beam interaction, and measurements from the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC) that validate the models and simulations. These models and simulations are structured to capture the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They also provide the opportunity to study diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Coupled-bunch instabilities and RF station power were the performance limiting effects for PEP-II. The sensitivity of the instabilities to individual LLRF parameters, the effectiveness of alternative operational algorithms, and the possible tradeoffs between RF loop and beam stability were studied. New algorithms were implemented, with significant performance improvement leading to a world record current during the last PEP-II run of 3212 mA for the Low Energy Ring. Longitudinal beam emittance growth due to RF noise is a major concern for LHC. Simulations studies and measurements were conducted that clearly show the correlation between RF noise and longitudinal bunch emittance, identify the major LLRF noise contributions, and determine the RF component dominating this effect. With these results, LHC upgrades and alternative algorithms are evaluated to reduce longitudinal emittance growth during operations. The applications of this work are described with regard to future machines and analysis of new technical implementations, as well as to possible future work which would continue the directions of this dissertation.

  9. Discussion of possible evidence for non-linear BCS resistance in SRF cavity data to model comparison

    SciTech Connect (OSTI)

    Bauer, P.; Solyak, N.; /Fermilab; Ciovati, G.L.; /Jefferson Lab; Eremeev, G.; /Cornell U., Phys. Dept.; Gurevich, A.; /Wisconsin U., Madison; Lilje, L.; /DESY; Visentin, B.; /Saclay

    2005-07-01

    Very powerful RF cavities are now being developed for future large-scale particle accelerators such as the International Linear Collider (ILC). The basic model for the cavity quality factor Q-slope in high gradient SRF cavities, i.e. the reduction of Q with increasing operating electric and magnetic fields, is the so-called thermal feedback model (TFBM). Most important for the agreement between the model and experimental data, however, is which different surface resistance contributions are included in the TFBM. This paper attempts to further clarify if the non-linear pair-breaking correction to the BCS resistance [1,2] is among those surface resistance contributions, through a comparison of TFBM calculations with experimental data from bulk Nb cavities built and tested at several different laboratories.

  10. Math 351: Linear Algebra

    E-Print Network [OSTI]

    Math 351: Linear Algebra. Text: Elementary Linear Algebra (by me). Instructor: Richard Penney. Office: 822 Mathematics Building Phone: 49--41968. E-mail: ...

  11. Accelerator Driven Nuclear Energy: The Thorium Option

    ScienceCinema (OSTI)

    Raja, Rajendran

    2010-01-08

    Conventional nuclear reactors use enriched Uranium as fuel and produce nuclear waste which needs to be stored away for over 10,000 years.   At the current rate of use, existing sources of Uranium will last for 50-100 years.  We describe a solution to the problem that uses particle accelerators to produce fast neutrons that can be used to burn existing nuclear waste and produce energy.  Such systems, initially proposed by Carlo Rubbia and collaborators in the 1990's, are being seriously considered by many countries as a possible solution to the green energy problem.  Accelerator driven reactors operate in a sub-critical regime and, thus, are safer and can obtain energy from plentiful elements such as Thorium-232 and Uranium-238. What is missing is the high intensity (10MW) accelerator that produces 1 GeV protons. We will describe scenarios which if implemented will make such systems a reality.  

  12. Particle physics---Experimental

    SciTech Connect (OSTI)

    Lord, J.J.; Boynton, P.E.; Burnett, T.H.; Wilkes, R.J.

    1991-08-21

    We are continuing a research program in particle astrophysics and high energy experimental particle physics. We have joined the DUMAND Collaboration, which is constructing a deep undersea astrophysical neutrino detector near Hawaii. Studies of high energy hadronic interactions using emulsion chamber techniques were also continued, using balloon flight exposures to ultra-high cosmic ray nuclei (JACEE) and accelerator beams. As members of the DUMAND Collaboration, we have responsibility for development a construction of critical components for the deep undersea neutrino detector facility. We have designed and developed the acoustical positioning system required to permit reconstruction of muon tracks with sufficient precision to meet the astrophysical goals of the experiment. In addition, we are making significant contributions to the design of the database and triggering system to be used. Work has been continuing in other aspects of the study of multiparticle production processes in nuclei. We are participants in a joint US/Japan program to study nuclear interactions at energies two orders of magnitude greater than those of existing accelerators, using balloon-borne emulsion chambers. On one of the flights we found two nuclear interactions of multiplicity over 1000 -- one with a multiplicity of over 2000 and pseudorapidity density {approximately} 800 in the central region. At the statistical level of the JACEE experiment, the frequency of occurrence of such events is orders of magnitude too large. We have continued our ongoing program to study hadronic interactions in emulsions exposed to high energy accelerator beams.

  13. The Light Ion Biomedical Research Accelerator (LIBRA)

    SciTech Connect (OSTI)

    Gough, R.A.

    1987-03-01

    LIBRA is a concept to place a light-ion, charged-particle facility in a hospital environment, and to dedicate it to applications in biology and medicine. There are two aspects of the program envisaged for LIBRA: a basic research effort coupled with a program in clinical applications of accelerated charged particles. The operational environment to be provided for LIBRA is one in which both of these components can coexist and flourish, and one that will promote the transfer of technology and knowledge from one to the other. In order to further investigate the prospects for a Light Ion Biomedical Research Accelerator (LIBRA), discussions are underway with the Merritt Peralta Medical Center (MPMC) in Oakland, California, and the University of California at San Francisco (UCSF). In this paper, a brief discussion of the technical requirements for such a facility is given, together with an outline of the accelerator technology required. While still in a preliminary stage, it is possible nevertheless to develop an adequate working description of the type, size, performance and cost of the accelerator facilities required to meet the preliminary goals for LIBRA.

  14. On radiation due to homogeneously accelerating sources

    E-Print Network [OSTI]

    Kalinov, D

    2015-01-01

    The core of this work is an old and broadly discussed problem of the electromagnetic radiation in the case of the hyperbolic motion. We prove that the radiation is non-zero in the lab (Minkowski) frame. Further, we attempt to understand this subject better by using co-moving non-inertial frames of reference, investigating other types of uniformly accelerated motion and, finally, using scalar waves instead of point-like particles as sources of radiation.

  15. Dual effects of stochastic heating on electron injection in laser wakefield acceleration

    SciTech Connect (OSTI)

    Deng, Z. G.; Wang, X. G., E-mail: wangxg@snnu.edu.cn [Department of Physics, Zhejiang University, Hangzhou 310027 (China); School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062 (China); Yang, L. [Department of Physics, Zhejiang University, Hangzhou 310027 (China); Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Zhou, C. T. [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Yu, M. Y. [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Ying, H. P. [Department of Physics, Zhejiang University, Hangzhou 310027 (China)

    2014-08-15

    Electron injection into the wakefield of an intense short laser pulse by a weaker laser pulse propagating in the opposite direction is reconsidered using two-dimensional (2D) particle-in-cell simulations as well as analytical modeling. It is found that for linearly polarized lasers the injection efficiency and the quality of the wakefield accelerated electrons increase with the intensity of the injection laser only up to a certain level, and then decreases. Theory and simulation tracking test electrons originally in the beat region of the two laser pulses show that the reduction of the injection efficiency at high injection-laser intensities is caused by stochastic overheating of the affected electrons.

  16. Optically active biological particle distinguishing apparatus

    DOE Patents [OSTI]

    Salzman, Gary C. (Los Alamos, NM); Kupperman, Robert H. (Washington, DC)

    1989-01-01

    The disclosure is directed to organic particle sorting and identification. High frequency pulses of circularly polarized light, alternating between left and right, intersect a fast moving stream of organic particles. Circular intensity differential scattering and linear intensity differential scattering are monitored to uniquely identify a variety of organic particles.

  17. Particle beam and crabbing and deflecting structure

    DOE Patents [OSTI]

    Delayen, Jean (Yorktown, VA)

    2011-02-08

    A new type of structure for the deflection and crabbing of particle bunches in particle accelerators comprising a number of parallel transverse electromagnetic (TEM)-resonant) lines operating in opposite phase from each other. Such a structure is significantly more compact than conventional crabbing cavities operating the transverse magnetic TM mode, thus allowing low frequency designs.

  18. SLIM, Short-pulse Technology for High Gradient Induction Accelerators

    SciTech Connect (OSTI)

    Arntz, Floyd; Kardo-Sysoev, A.; Krasnykh, A.; /SLAC

    2008-12-16

    A novel short-pulse concept (SLIM) suited to a new generation of a high gradient induction particle accelerators is described herein. It applies advanced solid state semiconductor technology and modern microfabrication techniques to a coreless induction method of charged particle acceleration first proven on a macro scale in the 1960's. Because this approach avoids use of magnetic materials there is the prospect of such an accelerator working efficiently with accelerating pulses in the nanosecond range and, potentially, at megahertz pulse rates. The principal accelerator section is envisioned as a stack of coreless induction cells, the only active element within each being a single, extremely fast (subnanosecond) solid state opening switch: a Drift Step Recovery Diode (DSRD). Each coreless induction cell incorporates an electromagnetic pulse compressor in which inductive energy developed within a transmission-line feed structure over a period of tens of nanoseconds is diverted to the acceleration of the passing charge packet for a few nanoseconds by the abrupt opening of the DSRD switch. The duration of this accelerating output pulse--typically two-to-four nanoseconds--is precisely determined by a microfabricated pulse forming line connected to the cell. Because the accelerating pulse is only nanoseconds in duration, longitudinal accelerating gradients approaching 100 MeV per meter are believed to be achievable without inciting breakdown. Further benefits of this approach are that, (1) only a low voltage power supply is required to produce the high accelerating gradient, and, (2) since the DSRD switch is normally closed, voltage stress is limited to a few nanoseconds per period, hence the susceptibility to hostile environment conditions such as ionizing radiation, mismatch (e.g. in medical applications the peak beam current may be low), strong electromagnetic noise levels, etc is expected to be minimal. Finally, we observe the SLIM concept is not limited to linac applications; for instance, it could be employed to both accelerate the beam and to stabilize the superbunch mode of operation in circular track machines.

  19. About Accelerators | Jefferson Lab

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

    Laser, though powered by a smaller SRF accelerator, holds power records in the production of infrared, ultraviolet and terahertz beams. The FEL has been used in a variety of...

  20. Operational status of the Brookhaven National Laboratory Accelerator Test Facility

    SciTech Connect (OSTI)

    Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, A.S.; Gallardo, J.; Jialin, Xie; Kirk, H.G.; Malone, R.G.; Parsa, Z.; Palmer, R.B.; Rao, T.; Rogers, J.; Sheehan, J.; Tsang, T.Y.F.; Ulc, S.; van Steenbergen, A.; Woodle, M.; Zhang, R.S. (Brookhaven National Lab., Upton, NY (USA)); Bigio, I.; Kurnit, N.; Shimada, T. (Los Alamos National Lab., NM (USA)); McDonald, K.T.; Russel, D.P. (Princeton Univ., NJ (USA)); Jiang,

    1990-01-01

    Initial design parameters and early operational results of a 50 MeV high brightness electron linear accelerator are described. The system utilizes a radio frequency electron gun operating at a frequency of 2.856 GHz and a nominal output energy of 4.5 MeV followed by two, 2{pi}/3 mode, disc loaded, traveling wave accelerating sections. The gun cathode is photo excited with short (6 psec) laser pulses giving design peak currents of a few hundred amperes. The system will be utilized to carry out infra-red FEL studies and investigation of new high gradient accelerating structures.