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


1

Linear particle accelerator with seal structure between electrodes and insulators  

DOE Patents [OSTI]

An electrostatic linear accelerator includes an electrode stack comprised of primary electrodes formed or Kovar and supported by annular glass insulators having the same thermal expansion rate as the electrodes. Each glass insulator is provided with a pair of fused-in Kovar ring inserts which are bonded to the electrodes. Each electrode is designed to define a concavo-convex particle trap so that secondary charged particles generated within the accelerated beam area cannot reach the inner surface of an insulator. Each insulator has a generated inner surface profile which is so configured that the electrical field at this surface contains no significant tangential component. A spark gap trigger assembly is provided, which energizes spark gaps protecting the electrodes affected by over voltage to prevent excessive energy dissipation in the electrode stack.

Broadhurst, John H. (Golden Valley, MN)

1989-01-01T23:59:59.000Z

2

A threshold for laser-driven linear particle acceleration in unbounded vacuum  

E-Print Network [OSTI]

We hypothesize that a charged particle in unbounded vacuum can be substantially accelerated by a force linear in the electric field of a propagating electromagnetic wave only if the accelerating field is capable of bringing ...

Wong, Liang Jie

2011-01-01T23:59:59.000Z

3

Non-linear model of particle acceleration at colliding shock flows  

E-Print Network [OSTI]

Powerful stellar winds and supernova explosions with intense energy release in the form of strong shock waves can convert a sizeable part of the kinetic energy release into energetic particles. The starforming regions are argued as a favorable site of energetic particle acceleration and could be efficient sources of nonthermal emission. We present here a non-linear time-dependent model of particle acceleration in the vicinity of two closely approaching fast magnetohydrodynamic (MHD) shocks. Such MHD flows are expected to occur in rich young stellar cluster where a supernova is exploding in the vicinity of a strong stellar wind of a nearby massive star. We find that the spectrum of the high energy particles accelerated at the stage of two closely approaching shocks can be harder than that formed at a forward shock of an isolated supernova remnant. The presented method can be applied to model particle acceleration in a variety of systems with colliding MHD flows.

Bykov, A M; Osipov, S M

2012-01-01T23:59:59.000Z

4

Non-perturbative aspects of particle acceleration in non-linear electrodynamics  

E-Print Network [OSTI]

We undertake an investigation of particle acceleration in the context of non-linear electrodynamics. We deduce the maximum energy that an electron can gain in a non-linear density wave in a magnetised plasma, and we show that an electron can `surf' a sufficiently intense Born-Infeld electromagnetic plane wave and be strongly accelerated by the wave. The first result is valid for a large class of physically reasonable modifications of the linear Maxwell equations, whilst the second result exploits the special mathematical structure of Born-Infeld theory.

David A. Burton; Stephen P. Flood; Haibao Wen

2015-01-18T23:59:59.000Z

5

Non-perturbative aspects of particle acceleration in non-linear electrodynamics  

E-Print Network [OSTI]

We undertake an investigation of particle acceleration in the context of non-linear electrodynamics. We deduce the maximum energy that an electron can gain in a non-linear density wave in a magnetised plasma, and we show that an electron can `surf' a sufficiently intense Born-Infeld electromagnetic plane wave and be strongly accelerated by the wave. The first result is valid for a large class of physically reasonable modifications of the linear Maxwell equations, whilst the second result exploits the special mathematical structure of Born-Infeld theory.

Burton, David A; Wen, Haibao

2015-01-01T23:59:59.000Z

6

History of Proton Linear Accelerators  

E-Print Network [OSTI]

much. References 1. Linear Accelerators, edited by P. M .at the 1986 Linear Accelerator Conference, SLAC, Stanford,HISTORY OF PROTON LINEAR ACCELERATORS Luis W. Alvarez TWO-

Alvarez, Luis W.

1987-01-01T23:59:59.000Z

7

On the continuum radio-spectrum of Cas A: possible evidence of the non-linear particle acceleration  

E-Print Network [OSTI]

Integrated radio-spectrum of Cas A in continuum was analyzed with special emphasis on possible high frequency spectral curvature. We conclude that the most probable scenario is that Planck's new data reveal the imprint of non-linear particle acceleration in the case of this young Galactic supernova remnant (SNR).

Oni?, D

2015-01-01T23:59:59.000Z

8

History of Proton Linear Accelerators  

E-Print Network [OSTI]

the board to show why the accelerator couldn't work. Then atmuch. References 1. Linear Accelerators, edited by P. M .at the 1986 Linear Accelerator Conference, SLAC, Stanford,

Alvarez, Luis W.

1986-01-01T23:59:59.000Z

9

Linear induction accelerator  

DOE Patents [OSTI]

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.

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

1988-06-21T23:59:59.000Z

10

Repair of overheating linear accelerator  

SciTech Connect (OSTI)

Los Alamos Neutron Science Center (LANSCE) is a proton accelerator that produces high energy particle beams for experiments. These beams include neutrons and protons for diverse uses including radiography, isotope production, small feature study, lattice vibrations and material science. The Drift Tube Linear Accelerator (DTL) is the first portion of a half mile long linear section of accelerator that raises the beam energy from 750 keV to 100 MeV. In its 31st year of operation (2003), the DTL experienced serious issues. The first problem was the inability to maintain resonant frequency at full power. The second problem was increased occurrences of over-temperature failure of cooling hoses. These shortcomings led to an investigation during the 2003 yearly preventative maintenance shutdown that showed evidence of excessive heating: discolored interior tank walls and coper oxide deposition in the cooling circuits. Since overheating was suspected to be caused by compromised heat transfer, improving that was the focus of the repair effort. Investigations revealed copper oxide flow inhibition and iron oxide scale build up. Acid cleaning was implemented with careful attention to protection of the base metal, selection of components to clean and minimization of exposure times. The effort has been very successful in bringing the accelerator through a complete eight month run cycle allowing an incredible array of scientific experiments to be completed this year (2003-2004). This paper will describe the systems, investigation analysis, repair, return to production and conclusion.

Barkley, Walter; Baldwin, William; Bennett, Gloria; Bitteker, Leo; Borden, Michael; Casados, Jeff; Fitzgerald, Daniel; Gorman, Fred; Johnson, Kenneth; Kurennoy, Sergey; Martinez, Alberto; O’Hara, James; Perez, Edward; Roller, Brandon; Rybarcyk, Lawrence; Stark, Peter; Stockton, Jerry

2004-01-01T23:59:59.000Z

11

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

SciTech Connect (OSTI)

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.

Russell, Steven J. [Los Alamos National Laboratory; Carlsten, Bruce E. [Los Alamos National Laboratory

2012-06-26T23:59:59.000Z

12

Charged particle accelerator grating  

DOE Patents [OSTI]

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.

Palmer, R.B.

1985-09-09T23:59:59.000Z

13

E-Print Network 3.0 - aps linear accelerator Sample Search Results  

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

TO ACCELERATOR PHYSICS Summary: : Kwang-Je Kim (kwangje@aps.anl.gov) Particle accelerators are becoming larger and more complex to satisfy... and the linear accelerator. In...

14

Cast dielectric composite linear accelerator  

DOE Patents [OSTI]

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.

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

2009-11-10T23:59:59.000Z

15

Acceleration-field calculation for a structure-based laser-driven linear accelerator  

E-Print Network [OSTI]

Acceleration-field calculation for a structure-based laser-driven linear accelerator Y. C. Huanga for publication 16 April 1998 A laser-driven particle accelerator, scaled to optical wavelengths, has a feature size many orders of magnitude smaller than a radio-frequency accelerator. However, similar to a radio

Byer, Robert L.

16

High field gradient particle accelerator  

DOE Patents [OSTI]

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 is disclosed. 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. 10 figs.

Nation, J.A.; Greenwald, S.

1989-05-30T23:59:59.000Z

17

High field gradient particle accelerator  

DOE Patents [OSTI]

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.

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

1989-01-01T23:59:59.000Z

18

Publications 1. "Calculation of Beam Loading in Linear Traveling Wave Electron Accelerators," Review of  

E-Print Network [OSTI]

Publications 1. "Calculation of Beam Loading in Linear Traveling Wave Electron Accelerators). 26 "Stochastic and Adiabatic Behavior of Particles Accelerated by Periodic Forces," (M. A. Lieberman

Kammen, Daniel M.

19

Particle Acceleration in Astrophysical Sources  

E-Print Network [OSTI]

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...

Amato, Elena

2015-01-01T23:59:59.000Z

20

Ultra-high vacuum photoelectron linear accelerator  

DOE Patents [OSTI]

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.

Yu, David U.L.; Luo, Yan

2013-07-16T23:59:59.000Z

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


21

Voltage regulation in linear induction accelerators  

DOE Patents [OSTI]

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.

Parsons, William M. (Santa Fe, NM)

1992-01-01T23:59:59.000Z

22

Voltage regulation in linear induction accelerators  

DOE Patents [OSTI]

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.

Parsons, W.M.

1992-12-29T23:59:59.000Z

23

Optimization Online - Accelerated Linearized Bregman Method  

E-Print Network [OSTI]

Jun 27, 2011 ... Abstract: In this paper, we propose and analyze an accelerated linearized Bregman (ALB) method for solving the basis pursuit and related ...

Bo Huang

2011-06-27T23:59:59.000Z

24

Cosmic Particle Acceleration: Basic Issues  

E-Print Network [OSTI]

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.

T. W. Jones

2000-12-22T23:59:59.000Z

25

Characterisation of electron beams from laser-driven particle accelerators  

SciTech Connect (OSTI)

The development, understanding and application of laser-driven particle accelerators require accurate measurements of the beam properties, in particular emittance, energy spread and bunch length. Here we report measurements and simulations showing that laser wakefield accelerators can produce beams of quality comparable to conventional linear accelerators.

Brunetti, E.; Manahan, G. G.; Shanks, R. P.; Islam, M. R.; Ersfeld, B.; Anania, M. P.; Cipiccia, S.; Issac, R. C.; Vieux, G.; Welsh, G. H.; Wiggins, S. M.; Jaroszynski, D. A. [Physics Department, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

2012-12-21T23:59:59.000Z

26

Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam  

DOE Patents [OSTI]

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.

Maschke, A.W.

1984-04-16T23:59:59.000Z

27

High-gradient compact linear accelerator  

DOE Patents [OSTI]

A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module. A faster wave propagates quicker to the third dielectric core across the dielectric plates with the closer spacing and lower dielectric constant. When the faster wave reaches the inner extents of the outer and inner conductive plates, it reflects back outward and reverses the field in that segment of the dielectric core. All the field segments in the dielectric core are then in unipolar agreement until the slower wave finally propagates to the third dielectric core across the dielectric plates with the wider spacing and higher dielectric constant. During such unipolar agreement, particles in the core are accelerated with gradients that exceed twenty megavolts per meter.

Carder, Bruce M. (205 Rogue River Hwy., Gold Hill, OR 97525)

1998-01-01T23:59:59.000Z

28

High-gradient compact linear accelerator  

DOE Patents [OSTI]

A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module. A faster wave propagates quicker to the third dielectric core across the dielectric plates with the closer spacing and lower dielectric constant. When the faster wave reaches the inner extents of the outer and inner conductive plates, it reflects back outward and reverses the field in that segment of the dielectric core. All the field segments in the dielectric core are then in unipolar agreement until the slower wave finally propagates to the third dielectric core across the dielectric plates with the wider spacing and higher dielectric constant. During such unipolar agreement, particles in the core are accelerated with gradients that exceed twenty megavolts per meter. 10 figs.

Carder, B.M.

1998-05-26T23:59:59.000Z

29

Proton linear accelerators: A theoretical and historical introduction  

SciTech Connect (OSTI)

From the beginning, the development of linear accelerators has followed a number of different directions. This report surveys the basic ideas and general principles of such machines, pointing out the problems that have led to the various improvements, with the hope that it may also aid further progress. After a brief historical survey, the principal aspects of accelerator theory are covered in some detail: phase stability, focusing, radio-frequency accelerating structures, the detailed calculation of particle dynamics, and space-charge effects at high intensities. These developments apply essentially to proton and ion accelerators, and only the last chapter deals with a few aspects relative to electrons. 134 refs.

Lapostolle, P.M.

1989-07-01T23:59:59.000Z

30

Radio-frequency quadrupole resonator for linear accelerator  

DOE Patents [OSTI]

An RFQ resonator for a linear accelerator having a reduced level of interfering modes and producing a quadrupole mode for focusing, bunching and accelerating beams of heavy charged particles, with the construction being characterized by four elongated resonating rods within a cylinder with the rods being alternately shorted and open electrically to the shell at common ends of the rods to provide an LC parallel resonant circuit when activated by a magnetic field transverse to the longitudinal axis.

Moretti, A.

1982-10-19T23:59:59.000Z

31

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample6, 2011Liisa O'Neill About Us LiisaLin WangLinear

32

Laser Plasma Particle Accelerators: Large Fields for Smaller Facility Sources  

E-Print Network [OSTI]

essential understanding of accelerator physics to advanceof high- gradient, laser plasma particle accelerators.to conventional particle accelerators, plasmas can sustain

Geddes, Cameron G.R.

2010-01-01T23:59:59.000Z

33

Microwaves and particle accelerators: a fundamental link  

SciTech Connect (OSTI)

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)

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

2011-07-01T23:59:59.000Z

34

Fermi National Accelerator Laboratory February 2014 Particle...  

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

accelerators to the World Wide Web, and from medical imaging techniques to high-performance computing, the bold and innovative ideas and technologies of particle physics have...

35

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region service area. TheEPSCI Home ItDark EnergyFermilab's Accelerator

36

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region service area. TheEPSCI Home ItDark EnergyFermilab's AcceleratorLHC

37

Particle accelerator employing transient space charge potentials  

DOE Patents [OSTI]

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.

Post, Richard F. (Walnut Creek, CA)

1990-01-01T23:59:59.000Z

38

Enhanced dielectric-wall linear accelerator  

DOE Patents [OSTI]

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.

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

1998-09-22T23:59:59.000Z

39

Non-accelerator Particle Physics  

E-Print Network [OSTI]

· Surface science: Prof Gratta #12;Sept 16, 09 Grad Sudent Orientation: Non Accel Particle Physics 4;Sept 16, 09 Grad Sudent Orientation: Non Accel Particle Physics 5 Composition of the Cosmos WIMPs WMAP best fit #12;Sept 16, 09 Grad Sudent Orientation: Non Accel Particle Physics 6 What is the dark matter

Wechsler, Risa H.

40

Superconducting Magnets for Particle Accelerators  

E-Print Network [OSTI]

Superconductivity has been the most influential technology in the field of accelerators in the last 30 years. Since the commissioning of the Tevatron, which demonstrated the use and operability of superconductivity on a large scale, superconducting magnets and rf cavities have been at the heart of all new large accelerators. Superconducting magnets have been the invariable choice for large colliders, as well as cyclotrons and large synchrotrons. In spite of the long history of success, superconductivity remains a difficult technology, requires adequate R&D and suitable preparation, and has a relatively high cost. Hence, it is not surprising that the development has also been marked by a few setbacks. This article is a review of the main superconducting accelerator magnet projects; it highlights the main characteristics and main achievements, and gives a perspective on the development of superconducting magnets for the future generation of very high energy colliders.

Rossi, L

2012-01-01T23:59:59.000Z

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


41

A Maxwellian Perspective on Particle Acceleration  

E-Print Network [OSTI]

A Maxwellian Perspective on Particle Acceleration K.T. McDonald Princeton U. (with Max Zolotorev, LBNL) March 31, 1998 http://puhep1.princeton.edu/~mcdonald/accel/ 1 #12;The Newtonian View A charge e and B change the particle's momentum, but only E can change it's energy. Integrate equation of motion

McDonald, Kirk

42

A Maxwellian Perspective on Particle Acceleration  

E-Print Network [OSTI]

A Maxwellian Perspective on Particle Acceleration K.T. McDonald Princeton U. (with Max Zolotorev, LBNL) March 31, 1998 http://puhep1.princeton.edu/~mcdonald/accel/ 1 #12; The Newtonian View A charge e): ) Both E and B change the particle's momentum, but only E can change it's energy. ) Integrate equation

McDonald, Kirk

43

A Maxwellian Perspective on Particle Acceleration  

E-Print Network [OSTI]

A Maxwellian Perspective on Particle Acceleration K.T. McDonald Princeton U. (with Max Zolotorev, LBNL) April 19, 1998 http://puhep1.princeton.edu/~mcdonald/accel/ 1 #12;The Newtonian View A charge e and B change the particle's momentum, but only E can change it's energy. Integrate equation of motion

McDonald, Kirk

44

A Maxwellian Perspective on Particle Acceleration  

E-Print Network [OSTI]

A Maxwellian Perspective on Particle Acceleration K.T. McDonald Princeton U. (with Max Zolotorev, LBNL) April 19, 1998 http://puhep1.princeton.edu/~mcdonald/accel/ 1 #12; The Newtonian View A charge e): ) Both E and B change the particle's momentum, but only E can change it's energy. ) Integrate equation

McDonald, Kirk

45

Machine Protection: Availability for Particle Accelerators  

E-Print Network [OSTI]

Machine availability is a key indicator for the performance of the next generation of particle accelerators. Availability requirements need to be carefully considered during the design phase to achieve challenging objectives in different fields, as e.g. particle physics and material science. For existing and future High-Power facilities, such as ESS (European Spallation Source) and HL-LHC (High-Luminosity LHC), operation with unprecedented beam power requires highly dependable Machine Protection Systems (MPS) to avoid any damage-induced downtime. Due to the high complexity of accelerator systems, finding the optimal balance between equipment safety and accelerator availability is challenging. The MPS architecture, as well as the choice of electronic components, have a large influence on the achievable level of availability. In this thesis novel methods to address the availability of accelerators and their protection systems are presented. Examples of studies related to dependable MPS architectures are given i...

Apollonio, Andrea; Schmidt, Ruediger

2015-03-16T23:59:59.000Z

46

Solar Flares and particle acceleration  

E-Print Network [OSTI]

of Glasgow, UK STFC Summer School, Armagh, 2012 #12;Solar flares: basics X-raysradiowavesParticles1AU Figure 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

47

The Klynac: An Integrated Klystron and Linear Accelerator  

SciTech Connect (OSTI)

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

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

2012-08-07T23:59:59.000Z

48

An Accelerated Linearized Alternating Direction Method of Multipliers  

E-Print Network [OSTI]

Feb 12, 2014 ... An Accelerated Linearized Alternating Direction Method of Multipliers. Yuyuan Ouyang(ouyang ***at*** ufl.edu) Yunmei Chen(yun ***at*** ...

Yuyuan Ouyang

2014-02-12T23:59:59.000Z

49

2010 Annual Planning Summary for Stanford Linear Accelerator...  

Energy Savers [EERE]

to be prepared in the next 24 months, and the planned cost and schedule for each NEPA review identified. 2010 Annual Planning Summary for Stanford Linear Accelerator Center...

50

Seventy Five Years of Particle Accelerators  

SciTech Connect (OSTI)

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.

Andy Sessler

2008-04-04T23:59:59.000Z

51

Seventy Five Years of Particle Accelerators  

ScienceCinema (OSTI)

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.

Andy Sessler

2013-06-11T23:59:59.000Z

52

Laser Plasma Particle Accelerators: Large Fields for Smaller Facility Sources  

E-Print Network [OSTI]

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

Geddes, Cameron G.R.

2010-01-01T23:59:59.000Z

53

On particle acceleration around shocks. I  

E-Print Network [OSTI]

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.

Mario Vietri

2003-03-28T23:59:59.000Z

54

Drift tube suspension for high intensity linear accelerators  

DOE Patents [OSTI]

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.

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

1980-03-11T23:59:59.000Z

55

Drift tube suspension for high intensity linear accelerators  

DOE Patents [OSTI]

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.

Liska, Donald J. (Los Alamos, NM); Schamaun, Roger G. (Los Alamos, NM); Clark, Donald C. (Los Alamos, NM); Potter, R. Christopher (Los Alamos, NM); Frank, Joseph A. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

56

Detecting chaos in particle accelerators through the frequency map analysis method  

E-Print Network [OSTI]

The motion of beams in particle accelerators is dominated by a plethora of non-linear effects which can enhance chaotic motion and limit their performance. The application of advanced non-linear dynamics methods for detecting and correcting these effects and thereby increasing the region of beam stability plays an essential role during the accelerator design phase but also their operation. After describing the nature of non-linear effects and their impact on performance parameters of different particle accelerator categories, the theory of non-linear particle motion is outlined. The recent developments on the methods employed for the analysis of chaotic beam motion are detailed. In particular, the ability of the frequency map analysis method to detect chaotic motion and guide the correction of non-linear effects is demonstrated in particle tracking simulations but also experimental data.

Yannis Papaphilippou

2014-06-05T23:59:59.000Z

57

FASTBUS for the particle accelerator laboratories  

SciTech Connect (OSTI)

The FASTBUS modular high speed data acquisition and control system for high energy physics and other applications was described by Costrell and Dawson at the 1983 Particle Accelerator Conference. Both the specification and the implementation of this interlaboratory development have progressed considerably since that time. Because of its many attractive features, FASTBUS is currently in use in several major nuclear and high energy physics laboratories and is also finding application in other areas. 10 refs.

Dawson, W.K.; Costrell, L.; Ikeda, H.; Ponting, P.J.; Walz, H.V.

1985-05-01T23:59:59.000Z

58

Laser Wakefield Particle Accelerators Project at NERSC  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickrinformationPostdocs spaceLaser Wakefield Particle Acceleration Laser

59

STANFORD LINEAR ACCELERATOR CENTER Stanford University  

E-Print Network [OSTI]

particle beams, and we look forward to interesting results on plasma focusing. Best personal regards

60

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

E-Print Network [OSTI]

of 2006 European Particle Accelerator Conf. , Edinburgh,Proc. 1992 European Particle Accelerator Conference, Berlin,in Proc. 2007 Particle Accelerator Conf. , Albuquerque, June

Zisman, Michael S.

2008-01-01T23:59:59.000Z

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


61

Novel Approach to Linear Accelerator Superconducting Magnet System  

SciTech Connect (OSTI)

Superconducting Linear Accelerators include a superconducting magnet system for particle beam transportation that provides the beam focusing and steering. This system consists of a large number of quadrupole magnets and dipole correctors mounted inside or between cryomodules with SCRF cavities. Each magnet has current leads and powered from its own power supply. The paper proposes a novel approach to magnet powering based on using superconducting persistent current switches. A group of magnets is powered from the same power supply through the common, for the group of cryomodules, electrical bus and pair of current leads. Superconducting switches direct the current to the chosen magnet and close the circuit providing the magnet operation in a persistent current mode. Two persistent current switches were fabricated and tested. In the paper also presented the results of magnetic field simulations, decay time constants analysis, and a way of improving quadrupole magnetic center stability. Such approach substantially reduces the magnet system cost and increases the reliability.

Kashikhin, Vladimir; /Fermilab

2011-11-28T23:59:59.000Z

62

Particle acceleration in relativistic subluminal shock environments  

E-Print Network [OSTI]

The understanding of the particle spectra resulting from acceleration in relativistic shocks as they occur in extragalactic sources, is essential for the interpretation of the cosmic ray spectrum above the ankle ($E_p>3\\cdot 10^{18}$ eV). It is believed that extragalactic sources like Active Galactic Nuclei and Gamma Ray Bursts can produce particle spectra up to $E_p\\sim 10^{21}$ eV. In this contribution, subluminal shocks are investigated with respect to different shock boost factors $\\Gamma$ and the inclination angle between the shock normal and the magnetic field $\\psi$. A correlation between the boost factor and the spectral behavior of the emitted particles is found. The results are compared to Active Galactic Nuclei and Gamma Ray Burst diffuse cosmic ray contribution and the observed cosmic ray spectrum at the highest energies.

A. Meli; J. Becker; J. J. Quenby; J. Luenemann

2007-08-10T23:59:59.000Z

63

PRODUCTION AND APPLICATIONS OF NEUTRONS USING PARTICLE ACCELERATORS  

SciTech Connect (OSTI)

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.

David L. Chichester

2009-11-01T23:59:59.000Z

64

PARTICLE ACCELERATION AT THE SUN AND IN THE HELIOSPHERE  

E-Print Network [OSTI]

in acceleration sources and, for shock acceleration, new evidence of energetic-proton-generated waves has come) Abstract. Energetic particles are accelerated in rich profusion at sites throughout the heliosphere new sources in situ. Most acceleration sources can be `seen' only by direct observation

Reames, Donald V.

65

INTRA BEAM SCATTERING IN LINEAR ACCELERATORS, ESPECIALLY ERLS  

E-Print Network [OSTI]

are called Touschek particles. Touschek scattering in a linear acceler- ator is interesting because. In this paper we describe two ways of simu- lating particle loss by these scattering affects, both imple- mented complete propagation of scattered particle. For the example of the ERL x-ray facility that Cornell plans

Hoffstaetter, Georg

66

The Klynac: An Integrated Klystron and Linear Accelerator  

SciTech Connect (OSTI)

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.

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

2013-04-01T23:59:59.000Z

67

The Klynac: An integrated klystron and linear accelerator  

SciTech Connect (OSTI)

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.

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)

2013-04-19T23:59:59.000Z

68

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

E-Print Network [OSTI]

H uge particle accelerators have been at the vanguard of research in particle physics for more than to develop new and more compact accelerator technologies. Threereports1­3 inthisissue(frompage535) announce counterparts, positrons, can then `surf' the electric field of a wave's wake. Particles have been accelerated

Geddes, Cameron Guy Robinson

69

Applications of pyroelectric particle accelerators Jeffrey A. Geuther, Yaron Danon *  

E-Print Network [OSTI]

Applications of pyroelectric particle accelerators Jeffrey A. Geuther, Yaron Danon * Rensselaer mounted to the crystal. By using the combined fields of two polarized crystals, the acceleration potential, and the target crystal is coated with deuterated target, the deuterium ions can be accelerated into the target

Danon, Yaron

70

Accelerators | Photon Science | Particle Physics Deutsches Elektronen-Synchrotron  

E-Print Network [OSTI]

Accelerators | Photon Science | Particle Physics Deutsches Elektronen-Synchrotron A Research Centre and astroparticle physics as well as accelerator physics. The Photo Injector Test Facility PITZ in Zeuthen (near XFEL. As part of the accelerator R&D program of the Helmholtz Association the focus of the research

71

Acceleration of low energy charged particles by gravitational waves  

E-Print Network [OSTI]

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.

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

2005-12-07T23:59:59.000Z

72

Accelerators | Photon Science | Particle Physics Deutsches Elektronen-Synchrotron  

E-Print Network [OSTI]

Accelerators | Photon Science | Particle Physics Deutsches Elektronen-Synchrotron A Research Centre/m) Accelerator Research DESY DESY is one of the world's leading research centres for photon science, particle with universities. The DESY focus is on conventional and plasma-based accele- rators with applications in photon

73

Linear Accelerator Facility, Kildee Hall aluminum, brick, concrete, rock, and  

E-Print Network [OSTI]

and demonstration facility for the irradiation of food and non-food materials. It is primarily used for the reduction or elimination of bacteria from foods and feed. Interior Garden is an environmental installation) are examples of the types of foodstuff that is irradiated in the Linear Accelerator Facility. The table has

Mayfield, John

74

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

DOE Patents [OSTI]

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.

Maschke, Alfred W. (East Moriches, NY)

1983-07-05T23:59:59.000Z

75

A particle accelerator employing transient space charge potentials  

DOE Patents [OSTI]

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.

Post, R.F.

1988-02-25T23:59:59.000Z

76

In-Situ Monitoring of Particle Growth at PEMFC Cathode under Accelerated Cycling Conditions  

SciTech Connect (OSTI)

An in-situ method to measure changes in catalyst particle size at the cathode of a proton exchange membrane fuel cell is demonstrated. Synchrotron X-rays, 58 keV, were used to measure the pair distribution function on an operating fuel cell and observe the growth of catalyst particles under accelerated degradation conditions. The stability of Pt/C and PtCo/C with different initial particle sizes was monitored over 3000 potential cycles. The increase in particle size was fit to a linear trend as a function of cycles. The most stable electrocatalyst was found to be the alloyed PtCo with the larger initial particle size.

Redmond, Erin L.; Setzler, Brian P.; Juhas, Pavol; Billinge, Simon J.L.; Fuller, Thomas F. (GIT); (Columbia)

2012-10-25T23:59:59.000Z

77

Particle acceleration in superluminal strong waves  

E-Print Network [OSTI]

We calculate the electron acceleration in random superluminal strong waves (SLSWs) and radiation from them by using numerical methods in the context of the termination shock of the pulsar wind nebulae. We pursue the electrons by solving the equation of motion in the analytically expressed electromagnetic turbulences. These consist of primary SLSW and isotropically distributed secondary electromagnetic waves. Under the dominance of the secondary waves, all electrons gain nearly equal energy. On the other hand, when the primary wave is dominant, selective acceleration occurs. The phase of the primary wave felt by the electrons moving nearly along the wavevector changes very slowly compared to the oscillation of the wave, which is called "phase locked", and such electrons are continuously accelerated. This acceleration by SLSWs may play a crucial role in the pre-acceleration for the shock acceleration. In general, the radiation from the phase-locked population is different from the synchro-Compton radiation. How...

Teraki, Yuto; Nagataki, Shigehiro

2015-01-01T23:59:59.000Z

78

A linear accelerator couch attachment for extended SSD treatments  

SciTech Connect (OSTI)

An attachment to an existing linear accelerator couch is described that extends the range of SSD's at which patients can be treated. This couch attachment, which is mounted on castors for ease of mobility, is attached to and locks into the rail of the accelerator couch such that the axis of the new device is normal to the existing couch. All motions of this assembly are then under the ocntrol of the existing couch. The overall size of the couch attachment is 215 cm x 90 cm, sufficiently large to treat all cleinically used fields.

Biggs, P.J.; Leong, J.C.

1983-04-01T23:59:59.000Z

79

Finite element analyses of a linear-accelerator electron gun  

SciTech Connect (OSTI)

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.

Iqbal, M., E-mail: muniqbal.chep@pu.edu.pk, E-mail: muniqbal@ihep.ac.cn [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wasy, A. [Department of Mechanical Engineering, Changwon National University, Changwon 641773 (Korea, Republic of)] [Department of Mechanical Engineering, Changwon National University, Changwon 641773 (Korea, Republic of); Islam, G. U. [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan)] [Centre for High Energy Physics, University of the Punjab, Lahore 45590 (Pakistan); Zhou, Z. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2014-02-15T23:59:59.000Z

80

Linear induction accelerator and pulse forming networks therefor  

DOE Patents [OSTI]

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.

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

1989-01-01T23:59:59.000Z

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


81

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

SciTech Connect (OSTI)

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.

Sessler, Andy

2006-07-26T23:59:59.000Z

82

A GPU Accelerated Smoothed Particle Hydrodynamics Capability For Houdini  

E-Print Network [OSTI]

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...

Sanford, Mathew

2012-10-19T23:59:59.000Z

83

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

ScienceCinema (OSTI)

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.

Sessler, Andy

2011-04-28T23:59:59.000Z

84

Superstructure for high current applications in superconducting linear accelerators  

DOE Patents [OSTI]

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.

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

2008-03-18T23:59:59.000Z

85

Accelerated Iterative Method for Solving Steady Solutions of Linearized Atmospheric Models  

E-Print Network [OSTI]

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

Watanabe, Masahiro

86

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region service area. TheEPSCI Home ItDark EnergyFermilab's AcceleratorLHC and

87

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

E-Print Network [OSTI]

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.

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

2013-01-01T23:59:59.000Z

88

Thermal Particle Injection in Nonlinear Diffusive Shock Acceleration  

E-Print Network [OSTI]

Particle acceleration in collisionless astrophysical shocks, i.e., diffusive shock acceleration (DSA), is the most likely mechanism for producing cosmic rays, at least below 10^{15} eV. Despite the success of this theory, several key elements, including the injection of thermal particles, remains poorly understood. We investigate injection in strongly nonlinear shocks by comparing a semi-analytic model of DSA with a Monte Carlo model. These two models treat injection quite differently and we show, for a particular set of parameters, how these differences influence the overall acceleration efficiency and the shape of the broad-band distribution function.

Donald C. Ellison; Pasquale Blasi; Stefano Gabici

2005-07-05T23:59:59.000Z

89

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

E-Print Network [OSTI]

under construc- tion at CERN in Geneva,will attempt to find the Higgs boson, a particle associatedH uge particle accelerators have been at the vanguard of research in particle physics for more than half a century; through high-energy collisions of accelera- ted particles, the fundamental building

Valero-Cuevas, Francisco

90

Wakefield Damping in a Pair of X-Band Accelerators for Linear Colliders  

SciTech Connect (OSTI)

We consider means to damp the wake-field left behind ultra-relativistic charges. In particular, we focus on a pair of travelling wave accelerators operating at an X-band frequency of 11.424 GHz. In order to maximize the efficiency of acceleration, in the context of a linear collider, multiple bunches of charged particles are accelerated within a given pulse of the electromagnetic field. The wake-field left behind successive bunches, if left unchecked, can seriously disturb the progress of trailing bunches and can lead to an appreciable dilution in the emittance of the beam. We report on a method to minimize the influence of the wake-field on trailing bunches. This method entails detuning the characteristic mode frequencies which make-up the electromagnetic field, damping the wake-field, and interleaving the frequencies of adjacent accelerating structures. Theoretical predictions of the wake-field and modes, based on a circuit model, are compared with experimental measurements of the wake-field conducted within the ASSET facility at SLAC. Very good agreement is obtained between theory and experiment and this allows us to have some confidence in designing the damping of wake-fields in a future linear collider consisting of several thousand of these accelerating structures.

Jones, R.M.; Adolphsen, C.E.; Wang, J.W.; Li, Z.; /SLAC

2006-12-18T23:59:59.000Z

91

Magnetic reconnection configurations and particle acceleration in solar flares  

E-Print Network [OSTI]

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

Chen, P. F.

92

Accelerators | Photon Science | Particle Physics Deutsches Elektronen-Synchrotron  

E-Print Network [OSTI]

Accelerators | Photon Science | Particle Physics Deutsches Elektronen-Synchrotron A Research Centre DESY DESY is one of the world's leading research centres for photon science, particle and astroparticle with universities. The DESY focus is on conventional and plasma-based accele- rators with applications in photon

93

A theory of two-beam acceleration of charged particles in a plasma waveguide  

SciTech Connect (OSTI)

The progress made in recent years in the field of high-current relativistic electron beam (REB) generation has aroused a considerable interest in studying REB potentialities for charged particle acceleration with a high acceleration rate T = 100MeV/m. It was proposed, in particular, to employ high-current REB in two-beam acceleration schemes (TBA). In these schemes high current REB (driving beam) excites intense electromagnetic waves in the electrodynamic structure which, in their turn, accelerate particles of the other beam (driven beam). The TBA schemes can be divided into two groups. The first group includes the schemes, where the two beams (driving and driven) propagate in different electrodynamic structures coupled with each other through the waveguides which ensure the microwave power transmission to accelerate driven beam particles. The second group includes the TBA schemes, where the driving and driven beams propagate in one electrodynamic structure. The main aim of this work is to demonstrate by theory the possibility of realizing effectively the TBA scheme in the plasma waveguide. The physical model of the TBA scheme under study is formulated. A set of equations describing the excitation of RF fields by a high-current REB and the acceleration of driven beam electrons is also derived. Results are presented on the the linear theory of plasma wave amplification by the driving beam. The range of system parameters, at which the plasma-beam instability develops, is defined. Results of numerical simulation of the TBA scheme under study are also presented. The same section gives the description of the dynamics of accelerated particle bunching in the high-current REB-excited field. Estimates are given for the accelerating field intensities in the plasma and electron acceleration rates.

Ostrovsky, A.O. [Kharkov Inst. of Physics and Technology (Ukraine)

1993-11-01T23:59:59.000Z

94

Linear accelerator x-ray sources with high duty cycle  

SciTech Connect (OSTI)

X-ray cargo inspection systems typically use a several-MV pulsed linear accelerator (linac) to produce a bremsstrahlung spectrum of x rays by bombarding a target with electrons. The x rays traverse the cargo and are detected by a detector array. Spectroscopy of the detected x rays is very desirable: if one can determine the spectrum of the transmitted x rays, one can determine the Z of the material they traversed. Even in relatively low-dose modes of operation, thousands of x rays arrive at each detector element during each pulse, unless the x rays are heavily absorbed or scattered by the cargo. For portal or fixed-site systems, dose rates, and therefore x-ray count rates, are even higher. Because of the high x-ray count rate, spectroscopy is impractical in conventional cargo inspection systems, except in certain special cases. For a mobile system, typical pulse durations are a few microseconds, and the number of pulses is on the order of 100 per second, leading to a duty factor of about 0.04%. Clearly, a linear accelerator x-ray source with much higher duty factor would be useful, since then the same number of x rays could be spread out over time, reducing the x-ray count rate. In this paper, we explore the possibility of designing a linear accelerator system, using more or less Conventional Off the Shelf (COTS) components, capable of duty cycles of 1% or greater. A survey was conducted of available linac RF source options and, given the possibilities, calculations were performed for suitable beam centerline designs. Keeping in mind that the size and cost of the accelerator system should be practical for use in a mobile cargo inspection system, only a few options are shown to be reasonably feasible, both requiring the use of klystrons instead of the magnetrons used in conventional systems. An S-Band design appears clearly possible, and there is also a promising X-Band design.

Condron, Cathie; Brown, Craig; Gozani, Tsahi; Langeveld, Willem G. J. [Rapiscan Laboratories, Inc., 520 Almanor Ave. Sunnyvale, CA 94085 (United States); Hernandez, Michael [XScell corp., 2134 Old Middlefield Way, Mountain View, CA 94043 (United States)

2013-04-19T23:59:59.000Z

95

Pulse Transformer Design for Magnet Powering in Particle Accelerators  

E-Print Network [OSTI]

This paper presents an optimal design procedure for pulse transformers fed by power converters for supplying pulsed current magnets in particle accelerators. Usually their volume must be minimized because of limited space available in the accelerator tunnel. Analytical and numerical models are presented as well as an experimental validation and a real case study where the design tool is exploited to derive a wide variety of solutions depending on the pulse transformers location with respect to the magnet position.

Aguglia, D

2014-01-01T23:59:59.000Z

96

Spinning Black Holes as Particle Accelerators  

E-Print Network [OSTI]

It has recently been pointed out that particles falling freely from rest at infinity outside a Kerr black hole can in principle collide with arbitrarily high center of mass energy in the limiting case of maximal black hole spin. Here we aim to elucidate the mechanism for this fascinating result, and to point out its practical limitations, which imply that ultra-energetic collisions cannot occur near black holes in nature.

Ted Jacobson; Thomas P. Sotiriou

2010-01-21T23:59:59.000Z

97

RF properties of periodic accelerating structures for linear colliders  

SciTech Connect (OSTI)

With the advent of the SLAC electron-positron linear collider (SLC) in the 100 GeV center-of-mass energy range, research and development work on even higher energy machines of this type has started in several laboratories in the United States, Europe, the Soviet Union and Japan. These linear colliders appear to provide the only promising approach to studying e/sup /plus//e/sup /minus// physics at center-of-mass energies approaching 1 TeV. This thesis concerns itself with the study of radio frequency properties of periodic accelerating structures for linear colliders and their interaction with bunched beams. The topics that have been investigated are: experimental measurements of the energy loss of single bunches to longitudinal modes in two types of structures, using an equivalent signal on a coaxial wire to simulate the beam; a method of canceling the energy spread created within a single bunch by longitudinal wakefields, through appropriate shaping of the longitudinal charge distribution of the bunch; derivation of the complete transient beam-loading equation for a train of bunches passing through a constant-gradient accelerator section, with application to the calculation and minimization of multi-bunch energy spread; detailed study of field emission and radio frequency breakdown in disk-loaded structures at S-, C- and X-band frequencies under extremely high-gradient conditions, with special attention to thermal effects, radiation, sparking, emission of gases, surface damage through explosive emission and its possible control through RF-gas processing. 53 refs., 49 figs., 9 tabs.

Wang, J.W.

1989-07-01T23:59:59.000Z

98

Charged spinning black holes as particle accelerators  

SciTech Connect (OSTI)

It has recently been pointed out that the spinning Kerr black hole with maximal spin could act as a particle collider with arbitrarily high center-of-mass energy. In this paper, we will extend the result to the charged spinning black hole, the Kerr-Newman black hole. The center-of-mass energy of collision for two uncharged particles falling freely from rest at infinity depends not only on the spin a but also on the charge Q of the black hole. We find that an unlimited center-of-mass energy can be approached with the conditions: (1) the collision takes place at the horizon of an extremal black hole; (2) one of the colliding particles has critical angular momentum; (3) the spin a of the extremal black hole satisfies (1/{radical}(3)){<=}(a/M){<=}1, where M is the mass of the Kerr-Newman black hole. The third condition implies that to obtain an arbitrarily high energy, the extremal Kerr-Newman black hole must have a large value of spin, which is a significant difference between the Kerr and Kerr-Newman black holes. Furthermore, we also show that, for a near-extremal black hole, there always exists a finite upper bound for center-of-mass energy, which decreases with the increase of the charge Q.

Wei Shaowen; Liu Yuxiao; Guo Heng; Fu Chune [Institute of Theoretical Physics, Lanzhou University, Lanzhou 730000 (China)

2010-11-15T23:59:59.000Z

99

Seminar Ia, cetrti letnik, stari program LONGITUDINAL DYNAMICS OF PARTICLES IN ACCELERATORS  

E-Print Network [OSTI]

Seminar Ia, cetrti letnik, stari program LONGITUDINAL DYNAMICS OF PARTICLES IN ACCELERATORS Author motion of charged particles in particle accelerators. The technique of acceleration by electromagnetic waves is explored and the stability of motion under such acceleration is inspected. The seminar

Â?umer, Slobodan

100

Cryogen free superconducting splittable quadrupole magnet for linear accelerators  

SciTech Connect (OSTI)

A new superconducting quadrupole magnet for linear accelerators was fabricated at Fermilab. The magnet is designed to work inside a cryomodule in the space between SCRF cavities. SCRF cavities must be installed inside a very clean room adding issues to the magnet design, and fabrication. The designed magnet has a splittable along the vertical plane configuration and could be installed outside of the clean room around the beam pipe previously connected to neighboring cavities. For more convenient assembly and replacement a 'superferric' magnet configuration with four racetrack type coils was chosen. The magnet does not have a helium vessel and is conductively cooled from the cryomodule LHe supply pipe and a helium gas return pipe. The quadrupole generates 36 T integrated magnetic field gradient, has 600 mm effective length, and the peak gradient is 54 T/m. In this paper the quadrupole magnetic, mechanical, and thermal designs are presented, along with the magnet fabrication overview and first test results.

Kashikhin, V.S.; Andreev, N.; Kerby, J.; Orlov, Y.; Solyak, N.; Tartaglia, M.; Velev, G.; /Fermilab

2011-09-01T23:59:59.000Z

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


101

Accurate and efficient spin integration for particle accelerators  

E-Print Network [OSTI]

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.

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

2015-01-01T23:59:59.000Z

102

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).

103

THE MAXIMUM ENERGY OF ACCELERATED PARTICLES IN RELATIVISTIC COLLISIONLESS SHOCKS  

SciTech Connect (OSTI)

The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as synchrotron radiation from electrons accelerated at the GRB external shock that propagates with relativistic velocities into the magnetized interstellar medium. By means of multi-dimensional particle-in-cell simulations, we investigate the acceleration performance of weakly magnetized relativistic shocks, in the magnetization range 0 {approx}< {sigma} {approx}< 10{sup -1}. The pre-shock magnetic field is orthogonal to the flow, as generically expected for relativistic shocks. We find that relativistic perpendicular shocks propagating in electron-positron plasmas are efficient particle accelerators if the magnetization is {sigma} {approx}< 10{sup -3}. For electron-ion plasmas, the transition to efficient acceleration occurs for {sigma} {approx}< 3 Multiplication-Sign 10{sup -5}. Here, the acceleration process proceeds similarly for the two species, since the electrons enter the shock nearly in equipartition with the ions, as a result of strong pre-heating in the self-generated upstream turbulence. In both electron-positron and electron-ion shocks, we find that the maximum energy of the accelerated particles scales in time as {epsilon}{sub max}{proportional_to}t {sup 1/2}. This scaling is shallower than the so-called (and commonly assumed) Bohm limit {epsilon}{sub max}{proportional_to}t, and it naturally results from the small-scale nature of the Weibel turbulence generated in the shock layer. In magnetized plasmas, the energy of the accelerated particles increases until it reaches a saturation value {epsilon}{sub sat}/{gamma}{sub 0} m{sub i}c {sup 2} {approx} {sigma}{sup -1/4}, where {gamma}{sub 0} m{sub i}c {sup 2} is the mean energy per particle in the upstream bulk flow. Further energization is prevented by the fact that the self-generated turbulence is confined within a finite region of thickness {proportional_to}{sigma}{sup -1/2} around the shock. Our results can provide physically grounded inputs for models of non-thermal emission from a variety of astrophysical sources, with particular relevance to GRB afterglows.

Sironi, Lorenzo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spitkovsky, Anatoly [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544-1001 (United States); Arons, Jonathan, E-mail: lsironi@cfa.harvard.edu [Department of Astronomy, Department of Physics, and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States)

2013-07-01T23:59:59.000Z

104

Automatic Beam Path Analysis of Laser Wakefield Particle Acceleration Data  

SciTech Connect (OSTI)

Numerical simulations of laser wakefield particle accelerators play a key role in the understanding of the complex acceleration process and in the design of expensive experimental facilities. As the size and complexity of simulation output grows, an increasingly acute challenge is the practical need for computational techniques that aid in scientific knowledge discovery. To that end, we present a set of data-understanding algorithms that work in concert in a pipeline fashion to automatically locate and analyze high energy particle bunches undergoing acceleration in very large simulation datasets. These techniques work cooperatively by first identifying features of interest in individual timesteps, then integrating features across timesteps, and based on the information derived perform analysis of temporally dynamic features. This combination of techniques supports accurate detection of particle beams enabling a deeper level of scientific understanding of physical phenomena than hasbeen possible before. By combining efficient data analysis algorithms and state-of-the-art data management we enable high-performance analysis of extremely large particle datasets in 3D. We demonstrate the usefulness of our methods for a variety of 2D and 3D datasets and discuss the performance of our analysis pipeline.

Rubel, Oliver; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Wu, Kesheng; Prabhat,; Weber, Gunther H.; Ushizima, Daniela M.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

2009-10-19T23:59:59.000Z

105

RESEARCH ON HIGH BEAM-CURRENT ACCELERATORS  

E-Print Network [OSTI]

and M. Wilson, Particle Accelerators 10, 223 13. A. I.Proc. 1976 Proton Linear Accelerator Conf. , Chalk River,and D. Keefe, Particle Accelerators~' 23. S. Humphries, J.

Keefe, Denis

2014-01-01T23:59:59.000Z

106

Particle acceleration at supernova shocks in young stellar clusters  

E-Print Network [OSTI]

We briefly discuss models of energetic particle acceleration by supernova shock in active starforming regions at different stages of their evolution. Strong shocks may strongly amplify magnetic fields due to cosmic ray driven instabilities. We discuss the magnetic field amplification emphasizing the role of the long-wavelength instabilities. Supernova shock propagating in the vicinity of a powerful stellar wind in a young stellar cluster is argued to increase the maximal CR energies at a given evolution stage of supernova remnant (SNR) and can convert a sizeable fraction of the kinetic energy release into energetic particles.

Bykov, A M; Osipov, S M

2011-01-01T23:59:59.000Z

107

Development of an RF Conditioning System for Charged-Particle Accelerators  

SciTech Connect (OSTI)

Charged-particle accelerators use various vacuum windows on their accelerating radio-frequency (RF) cavities to throughput very high RF power. Before being placed on the cavities, the windows should be cleaned, baked, and fully RF conditioned to prevent a poor vacuum from outgassing, as well as other forms of contamination. An example is the coaxial fundamental power coupler (FPC) with an annular alumina ceramic window for each of the 81 superconducting RF cavities in the Spallation Neutron Source (SNS) linear accelerator. The FPCs needed to be tested up to 650-kW peak in a traveling wave and 2.6 MW with standing wave peaks in 1.3 and 60 pulses/s at 805 MHz. In this paper, an Experimental-Physics-and-Industrial-Control-System-based RF conditioning system for the SNS RF test facility is presented. This paper summarizes the hardware and software design strategies, provides the results obtained, and describes the future research scope.

Kang, Yoon W [ORNL; Howlader, Mostofa [ORNL; Shajedul Hasan, Dr. S. M. [Virginia Polytechnic Institute and State University (Virginia Tech)

2008-01-01T23:59:59.000Z

108

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

SciTech Connect (OSTI)

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.

Not Available

1988-07-01T23:59:59.000Z

109

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

SciTech Connect (OSTI)

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.

Brown, Michael R.

2006-11-16T23:59:59.000Z

110

Particle acceleration and radiation in Pulsar Wind Nebulae  

E-Print Network [OSTI]

Pulsar Wind Nebulae are the astrophysical sources that host the most relativistic shocks in Nature and the only Galactic sources in which we have direct evidence of PeV particles. These facts make them very interesting from the point of view of particle acceleration physics, and their proximity and brightness make them a place where fundamental processes common to different classes of relativistic sources have a better chance to be understood. I will discuss how well we understand the physics of Pulsar Wind Nebulae, describing recent progress and highlighting the main open questions. I will be mostly concerned with the subject of particle acceleration, but, as we will see, in order to clarify the physics of this process, it is important to determine the conditions of the plasma in the nebula. These in turn can only be constrained through detailed modelling of the PWN dynamics and radiation. The shock in the Crab Nebula is probably the most efficient accelerator known, both in terms of conversion of the flow e...

Amato, Elena

2015-01-01T23:59:59.000Z

111

CONSTRAINTS ON LASER-DRIVEN ACCELERATORS FOR A HIGH-ENERGY LINEAR COLLIDER*  

E-Print Network [OSTI]

CONSTRAINTS ON LASER-DRIVEN ACCELERATORS FOR A HIGH-ENERGY LINEAR COLLIDER* J.S. Wurtele and AV on 1 TeV) are applied to free-space laser and laser/plasma accelerators. It is shown that the requirements impose very severe constraints upon the new accelerators-- so severe, that it seems unlikely

Wurtele, Jonathan

112

Failure Analysis of the Beam Vacuum in the Superconducting Cavities of the TESLA Main Linear Accelerator  

E-Print Network [OSTI]

1 Failure Analysis of the Beam Vacuum in the Superconducting Cavities of the TESLA Main Linear Hamburg, Germany Abstract For the long term successful operation of the superconducting TESLA accelerator The beam vacuum system of the TESLA main linear accelerators contains about 20.000 superconducting cavities

113

Tuning the DARHT Axis-II linear induction accelerator focusing  

SciTech Connect (OSTI)

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.

Ekdahl, Carl A. [Los Alamos National Laboratory

2012-04-24T23:59:59.000Z

114

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

SciTech Connect (OSTI)

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.

N /A

2007-08-01T23:59:59.000Z

115

DIFFUSIVE ACCELERATION OF PARTICLES AT OBLIQUE, RELATIVISTIC, MAGNETOHYDRODYNAMIC SHOCKS  

SciTech Connect (OSTI)

Diffusive shock acceleration (DSA) at relativistic shocks is expected to be an important acceleration mechanism in a variety of astrophysical objects including extragalactic jets in active galactic nuclei and gamma-ray bursts. These sources remain good candidate sites for the generation of ultrahigh energy cosmic rays. In this paper, key predictions of DSA at relativistic shocks that are germane to the production of relativistic electrons and ions are outlined. The technique employed to identify these characteristics is a Monte Carlo simulation of such diffusive acceleration in test-particle, relativistic, oblique, magnetohydrodynamic (MHD) shocks. Using a compact prescription for diffusion of charges in MHD turbulence, this approach generates particle angular and momentum distributions at any position upstream or downstream of the shock. Simulation output is presented for both small angle and large angle scattering scenarios, and a variety of shock obliquities including superluminal regimes when the de Hoffmann-Teller frame does not exist. The distribution function power-law indices compare favorably with results from other techniques. They are found to depend sensitively on the mean magnetic field orientation in the shock, and the nature of MHD turbulence that propagates along fields in shock environs. An interesting regime of flat-spectrum generation is addressed; we provide evidence for it being due to shock drift acceleration, a phenomenon well known in heliospheric shock studies. The impact of these theoretical results on blazar science is outlined. Specifically, Fermi Large Area Telescope gamma-ray observations of these relativistic jet sources are providing significant constraints on important environmental quantities for relativistic shocks, namely, the field obliquity, the frequency of scattering, and the level of field turbulence.

Summerlin, Errol J. [Heliospheric Physics Laboratory, Code 672, NASA's Goddard Space Flight Center, Greenbelt, MD 20770 (United States); Baring, Matthew G., E-mail: errol.summerlin@nasa.gov, E-mail: baring@rice.edu [Department of Physics and Astronomy, MS 108, Rice University, Houston, TX 77251 (United States)

2012-01-20T23:59:59.000Z

116

New modes of particle accelerations techniques and sources. Formal report  

SciTech Connect (OSTI)

This Report includes copies of transparencies and notes from the presentations made at the Symposium on New Modes of Particle Accelerations - Techniques and Sources, August 19-23, 1996 at the Institute for Theoretical Physics, University of California, Santa Barbara California, that was made available by the authors. Editing, reduction and changes to the authors contributions were made only to fulfill the printing and publication requirements. We would like to take this opportunity and thank the speakers for their informative presentations and for providing copies of their transparencies and notes for inclusion in this Report.

Parsa, Z. [ed.

1996-12-31T23:59:59.000Z

117

FLUKA calculations of radionuclides, star, and neutron fluence in soil around high-energy electron and proton linear accelerators  

E-Print Network [OSTI]

FLUKA calculations of radionuclides, star, and neutron fluence in soil around high-energy electron and proton linear accelerators

Puryear, A; Rokni, S H

2002-01-01T23:59:59.000Z

118

Particle acceleration and radiation by direct electric fields in flaring complex solar active regions  

E-Print Network [OSTI]

to connect the energy re- lease process with the acceleration of electrons in solar flares, using a CA modelParticle acceleration and radiation by direct electric fields in flaring complex solar active-Meudon, 92195 Meudon Cedex, FRANCE Abstract The acceleration and radiation of solar energetic particles

Anastasiadis, Anastasios

119

Design Considerations for Plasma Accelerators Driven by Lasers or Particle Beams  

E-Print Network [OSTI]

Design Considerations for Plasma Accelerators Driven by Lasers or Particle Beams C. B. Schroeder, E of an intense laser or the space-charge force of a charged particle beam. The implications for accelerator design and the different physical mechanisms of laser-driven and beam-driven plasma acceleration

Geddes, Cameron Guy Robinson

120

Randomly accelerated particle in a box: Mean absorption time for partially absorbing and inelastic boundaries  

E-Print Network [OSTI]

Randomly accelerated particle in a box: Mean absorption time for partially absorbing and inelastic which is randomly accelerated by Gaussian white noise on the line segment 0 x 1 and is absorbed as soon accelerated particle which moves on the half line x 0 with an absorbing boundary at x=0. The motion

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


121

Waveguides in three-dimensional photonic bandgap materials for particle-accelerator on a  

E-Print Network [OSTI]

Waveguides in three-dimensional photonic bandgap materials for particle-accelerator on a chip@physics.anu.edu.au Abstract: The quest for less costly and more compact high-energy particle accelerators of suggested concepts, the photonic accelerator design by B. M. Cowan [Phys. Rev. ST Accel. Beams 11, 011301

Byer, Robert L.

122

Particle Tracking in Circular Accelerators Using the Exact Hamiltonian in SixTrack  

E-Print Network [OSTI]

Particle motion in accelerators is in general complex. Tracking codes are developed to simulate beam dynamics in accelerators. SixTrack is a long lived particle tracking code maintained at CERN, the European Organization for Nuclear Research. A particle accelerator consists of a large number of magnets and other electromagnetic devices that guide the particle through the accelerator. Each device defines its own equation of motion, which often cannot be solved exactly. For this purpose, a number of approximations are introduced in order to facilitate the solution and to speed up the computation. In a high-energy accelerator, the particle has small transverse momentum components. This is exploited in the small-angle approximation. In this approximation the equations of motion are expanded to a low order in the transverse momentum components. In low-energy particle accelerators, or in tracking with large momentum deviations, this approximation is invalid. The equations of motion of a particle passing through a f...

Fjellstrom, Mattias; Hansson, Johan

2013-12-13T23:59:59.000Z

123

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

SciTech Connect (OSTI)

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

Dunn, M.E.

2006-02-27T23:59:59.000Z

124

Feature-based Analysis of Plasma-based Particle Acceleration Data  

SciTech Connect (OSTI)

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.

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

2013-07-05T23:59:59.000Z

125

DNS AND LES WITH STOCHASTIC MODELLING OF SUBGRID ACCELERATION APPLIED TO SOLID PARTICLES IN A HIGH  

E-Print Network [OSTI]

), these phenomena were coupled with particle acceler- ation statistics. In our paper, such statisticsDNS AND LES WITH STOCHASTIC MODELLING OF SUBGRID ACCELERATION APPLIED TO SOLID PARTICLES IN A HIGH Ecully, F-69134, France mikhael.gorokhovski@ec-lyon.fr ABSTRACT Inertial particle acceleration statistics

Boyer, Edmond

126

SINGLE CRYSTAL NIOBIUM TUBES FOR PARTICLE COLLIDERS ACCELERATOR CAVITIES  

SciTech Connect (OSTI)

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

MURPHY, JAMES E [University of Nevada, Reno] [University of Nevada, Reno

2013-02-28T23:59:59.000Z

127

The Mysterious Universe - Exploring Our World with Particle Accelerators  

ScienceCinema (OSTI)

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.

Brau, James E [University of Oregon

2014-06-25T23:59:59.000Z

128

E-Print Network 3.0 - accelerated charged particles Sample Search...  

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

"Space charge debunching and compensation in a laser particle acceleration system... Optronics, 2755 Northup Way, Bellevue, WA 98004-1495 Abstract. Laser ... Source: Brookhaven...

129

E-Print Network 3.0 - accelerated 56fe particles Sample Search...  

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

Search Powered by Explorit Topic List Advanced Search Sample search results for: accelerated 56fe particles Page: << < 1 2 3 4 5 > >> 1 RADIATION RESEARCH 162, 655659 (2004)...

130

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

Energy Savers [EERE]

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...

131

Diagnostic resonant cavity for a charged particle accelerator  

DOE Patents [OSTI]

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.

Barov, Nikolai (San Diego, CA)

2007-10-02T23:59:59.000Z

132

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

DOE Patents [OSTI]

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.

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

1991-01-01T23:59:59.000Z

133

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

DOE Patents [OSTI]

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.

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

1990-03-19T23:59:59.000Z

134

Cavitation Inception on Microparticles: A Self-Propelled Particle Accelerator Manish Arora,1  

E-Print Network [OSTI]

Cavitation Inception on Microparticles: A Self-Propelled Particle Accelerator Manish Arora,1 Claus) Corrugated, hydrophilic particles with diameters between 30 and 150 m are found to cause cavitation inception of the particle and the displaced liquid. The analysis suggests that all particles which cause cavitation

Ohl, Claus-Dieter

135

Acceleration statistics of solid particles in turbulent channel flow R. Zamansky, I. Vinkovic, and M. Gorokhovski  

E-Print Network [OSTI]

) suggesting that when particle inertia increases, particle acceler- ation variance decreases due to bothAcceleration statistics of solid particles in turbulent channel flow R. Zamansky, I. Vinkovic in near-wall turbulence Phys. Fluids 24, 035110 (2012) Smoothed particle hydrodynamics simulations

Boyer, Edmond

136

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

E-Print Network [OSTI]

Shock Acceleration of the Energetic Particle Background in the Solar Wind David T. Sodaitis Physics Department, University of New Hampshire Durham, New Hampshire, USA sodaitis@cisunix.unh.edu ABSTRACT Lee with solar energetic particle (SEP) events (Desai et al. 2003) have shown that shock acceleration may act

137

Application of High-performance Visual Analysis Methods to Laser Wakefield Particle Acceleration Data  

E-Print Network [OSTI]

Application of High-performance Visual Analysis Methods to Laser Wakefield Particle Acceleration, time- varying laser wakefield particle accelerator simulation data. We ex- tend histogramBit, a state-of-the-art index/query technology, to acceler- ate data mining and multi-dimensional histogram

138

DC-like Phase Space Manipulation and Particle Acceleration Using Chirped AC Fields  

SciTech Connect (OSTI)

Waves in plasmas can accelerate particles that are resonant with the wave. A DC electric field also accelerates particles, but without a resonance discrimination, which makes the acceleration mechanism profoundly different. We investigate the effect on a Hamiltonian distribution of an accelerating potential waveform, which could, for example, represent the average ponderomotive effect of two counterpropagating electromagnetic waves. In particular, we examine the apparent DC-like time-asymptotic response of the distribution in regimes where the potential structure is accelerated adiabatically. A highly resonant population within the distribution is always present, and we characterize its nonadiabatic response during wave-particle resonance using an integral method in the noninertial reference frame moving with the wave. Finally, we show that in the limit of infinitely slow acceleration of the wave, these highly resonant particles disappear and the response

P.F. Schmit and N.J. Fisch

2009-06-17T23:59:59.000Z

139

Generalized linear Boltzmann equations for particle transport in polycrystals  

E-Print Network [OSTI]

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.

Jens Marklof; Andreas Strömbergsson

2015-02-13T23:59:59.000Z

140

Advance in Vertical Buffered Electropolishing on Niobium for Particle Accelerators*  

SciTech Connect (OSTI)

Niobium (Nb) is the most popular material that has been employed for making superconducting radio frequency (SRF) cavities to be used in various particle accelerators over the last couple of decades. One of the most important steps in fabricating Nb SRF cavities is the final chemical removal of 150 {mu}m of Nb from the inner surfaces of the SRF cavities. This is usually done by either buffered chemical polishing (BCP) or electropolishing (EP). Recently a new Nb surface treatment technique called buffered electropolishing (BEP) has been developed at Jefferson Lab. It has been demonstrated that BEP can produce the smoothest surface finish on Nb ever reported in the literature while realizing a Nb removal rate as high as 10 {mu}m/min that is more than 25 and 5 times quicker than those of EP and BCP(112) respectively. In this contribution, recent advance in optimizing and understanding BEP treatment technique is reviewed. Latest results from RF measurements on BEP treated Nb single cell cavities by our unique vertical polishing system will be reported.

A.T. Wu, S. Jin, J.D. Mammosser, C.E. Reece, R.A. Rimmer,L. Lin, X.Y. Lu, K. Zhao

2011-09-01T23:59:59.000Z

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


141

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

SciTech Connect (OSTI)

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.

Neergaard Parker, L.; Zank, G. P., E-mail: lnp0012@uah.edu [Physics Department, Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

2012-09-20T23:59:59.000Z

142

International Linear Collider Accelerator Physics R&D  

SciTech Connect (OSTI)

ILC work at Illinois has concentrated primarily on technical issues relating to the design of the accelerator. Because many of the problems to be resolved require a working knowledge of classical mechanics and electrodynamics, most of our research projects lend themselves well to the participation of undergraduate research assistants. The undergraduates in the group are scientists, not technicians, and find solutions to problems that, for example, have stumped PhD-level staff elsewhere. The ILC Reference Design Report calls for 6.7 km circumference damping rings (which prepare the beams for focusing) using “conventional” stripline kickers driven by fast HV pulsers. Our primary goal was to determine the suitability of the 16 MeV electron beam in the AŘ region at Fermilab for precision kicker studies.We found that the low beam energy and lack of redundancy in the beam position monitor system complicated the analysis of our data. In spite of these issues we concluded that the precision we could obtain was adequate to measure the performance and stability of a production module of an ILC kicker, namely 0.5%. We concluded that the kicker was stable to an accuracy of ~2.0% and that we could measure this precision to an accuracy of ~0.5%. As a result, a low energy beam like that at AŘ could be used as a rapid-turnaround facility for testing ILC production kicker modules. The ILC timing precision for arrival of bunches at the collision point is required to be 0.1 picosecond or better. We studied the bunch-to-bunch timing accuracy of a “phase detector” installed in AŘ in order to determine its suitability as an ILC bunch timing device. A phase detector is an RF structure excited by the passage of a bunch. Its signal is fed through a 1240 MHz high-Q resonant circuit and then down-mixed with the AŘ 1300 MHz accelerator RF. We used a kind of autocorrelation technique to compare the phase detector signal with a reference signal obtained from the phase detector’s response to an event at the beginning of the run. We determined that the device installed in our beam, which was instrumented with an 8-bit 500 MHz ADC, could measure the beam timing to an accuracy of 0.4 picoseconds. Simulations of the device showed that an increase in ADC clock rate to 2 GHz would improve measurement precision by the required factor of four. As a result, we felt that a device of this sort, assuming matters concerning dynamic range and long-term stability can be addressed successfully, would work at the ILC. Cost effective operation of the ILC will demand highly reliable, fault tolerant and adaptive solutions for both hardware and software. The large numbers of subsystems and large multipliers associated with the modules in those subsystems will cause even a strong level of unit reliability to become an unacceptable level of system availability. An evaluation effort is underway to evaluate standards associated with high availability, and to guide ILC development with standard practices and well-supported commercial solutions. One area of evaluation involves the Advanced Telecom Computing Architecture (ATCA) hardware and software. We worked with an ATCA crate, processor monitors, and a small amount of ATCA circuit boards in order to develop a backplane “spy” board that would let us watch the ATCA backplane communications and pursue development of an inexpensive processor monitor that could be used as a physics-driven component of the crate-level controls system. We made good progress, and felt that we had determined a productive direction to extend this work. We felt that we had learned enough to begin designing a workable processor monitor chip if there were to be sufficient interest in ATCA shown by the ILC community. Fault recognition is a challenging issue in the crafting a high reliability controls system. With tens of thousands of independent processors running hundreds of thousands of critical processes, how can the system identify that a problem has arisen and determine the appropriate steps to take to correct, or compensate, for the

George D. Gollin; Michael Davidsaver; Michael J. Haney; Michael Kasten; Jason Chang; Perry Chodash; Will Dluger; Alex Lang; Yehan Liu

2008-09-03T23:59:59.000Z

143

MODELING FOCUSED ACCELERATION OF COSMIC-RAY PARTICLES BY STOCHASTIC METHODS  

SciTech Connect (OSTI)

Schlickeiser and Shalchi suggested that a first-order Fermi mechanism of focused particle acceleration could be important in several astrophysical applications. In order to investigate focused acceleration, we express the Fokker-Planck equation as an equivalent system of stochastic differential equations. We simplify the system for a set of physically motivated parameters, extend the analytical theory, and determine the evolving particle distribution numerically. While our numerical results agree with the focused acceleration rate of Schlickeiser and Shalchi for a weakly anisotropic particle distribution, we establish significant limitations of the analytical approach. Momentum diffusion is found to be more significant than focused acceleration at early times. Most critically, the particle distribution rapidly becomes anisotropic, leading to a much slower momentum gain rate. We discuss the consequences of our results for the role of focused acceleration in astrophysics.

Armstrong, C. K.; Litvinenko, Yuri E.; Craig, I. J. D., E-mail: cka3@waikato.ac.nz, E-mail: yuril@waikato.ac.nz, E-mail: i.craig@waikato.ac.nz [Department of Mathematics, University of Waikato, P. B. 3105, Hamilton (New Zealand)

2012-10-01T23:59:59.000Z

144

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

SciTech Connect (OSTI)

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.

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

2014-04-15T23:59:59.000Z

145

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

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

Cousineau and Jeff Holmes taught "Fundamentals of Accelerator Physics and Technology with Simulations and Measurements Lab." During the two weeks, instructors and teaching...

146

Particle Accelerators, 1990, Vol. 32, pp. 241-247 Reprints available directly from the publisher  

E-Print Network [OSTI]

profile is importa.nt for the study of laser acceler- ation of particles. For a specific relation betweenParticle Accelerators, 1990, Vol. 32, pp. 241-247 Reprints available directly from the publisher in plasma. Carrying out numerical particle simulation runs in which a deviation from this relation

Morrison, Philip J.,

147

Development of High-Gradient Dielectric Laser-Driven Particle Accelerator Structures  

SciTech Connect (OSTI)

The thrust of Stanford's program is to conduct research on high-gradient dielectric accelerator structures driven with high repetition-rate, tabletop infrared lasers. The close collaboration between Stanford and SLAC (Stanford Linear Accelerator Center) is critical to the success of this project, because it provides a unique environment where prototype dielectric accelerator structures can be rapidly fabricated and tested with a relativistic electron beam.

Byer, Robert L.

2013-11-07T23:59:59.000Z

148

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

E-Print Network [OSTI]

Accelerator (LEIA) generates DD and D3 He fusion products for the development of nuclear diagnostics for OmegaUpgrade of the MIT Linear Electrostatic Ion Accelerator (LEIA) for nuclear diagnostics development Graaff accelerator terminal Rev. Sci. Instrum. 83, 02A340 (2012) Status of ion sources at National

149

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

SciTech Connect (OSTI)

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.

Lawrence, G. [comp.

1997-07-01T23:59:59.000Z

150

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickrinformationPostdocsCenterCenter (LMI-EFRC)

151

Acceleration of heavy and light particles in turbulence: comparison between experiments and direct numerical simulations  

E-Print Network [OSTI]

We compare experimental data and numerical simulations for the dynamics of inertial particles with finite density in turbulence. In the experiment, bubbles and solid particles are optically tracked in a turbulent flow of water using an Extended Laser Doppler Velocimetry technique. The probability density functions (PDF) of particle accelerations and their auto-correlation in time are computed. Numerical results are obtained from a direct numerical simulation in which a suspension of passive pointwise particles is tracked, with the same finite density and the same response time as in the experiment. We observe a good agreement for both the variance of acceleration and the autocorrelation timescale of the dynamics; small discrepancies on the shape of the acceleration PDF are observed. We discuss the effects induced by the finite size of the particles, not taken into account in the present numerical simulations.

R. Volk; E. Calzavarini; G. Verhille; D. Lohse; N. Mordant; J. -F. Pinton; F. Toschi

2007-10-17T23:59:59.000Z

152

High-energy particle acceleration in the shell of a supernova remnant  

E-Print Network [OSTI]

A significant fraction of the energy density of the interstellar medium is in the form of high-energy charged particles (cosmic rays). The origin of these particles remains uncertain. Although it is generally accepted that the only sources capable of supplying the energy required to accelerate the bulk of Galactic cosmic rays are supernova explosions, and even though the mechanism of particle acceleration in expanding supernova remnant (SNR) shocks is thought to be well understood theoretically, unequivocal evidence for the production of high-energy particles in supernova shells has proven remarkably hard to find. Here we report on observations of the SNR RX J1713.7-3946 (G347.3-0.5), which was discovered by ROSAT in the X-ray spectrum and later claimed as a source of high-energy \\gamma-rays of TeV energies (1 TeV=10^{12} eV). We present a TeV \\gamma-ray image of the SNR: the spatially resolved remnant has a shell morphology similar to that seen in X-rays, which demonstrates that very-high-energy particles are accelerated there. The energy spectrum indicates efficient acceleration of charged particles to energies beyond 100 TeV, consistent with current ideas of particle acceleration in young SNR shocks.

H. E. S. S. Collaboration; :; F. Aharonian

2004-11-18T23:59:59.000Z

153

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

SciTech Connect (OSTI)

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.

Cooper, R.K. (comp.)

1990-07-01T23:59:59.000Z

154

Quasi-linear heating and acceleration in bi-Maxwellian plasmas  

SciTech Connect (OSTI)

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.

Hellinger, Petr [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic)] [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic); Passot, Thierry; Sulem, Pierre-Louis [Université de Nice Sophia Antipolis, CNRS, Observatoire de la Côte d'Azur, BP 4229, 06304 Nice Cedex 4 (France)] [Université de Nice Sophia Antipolis, CNRS, Observatoire de la Côte d'Azur, BP 4229, 06304 Nice Cedex 4 (France); Trávní?ek, Pavel M. [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic) [Astronomical Institute and Institute of Atmospheric Physics, AS CR Bocni II/1401, CZ-14131 Prague (Czech Republic); Space Sciences Laboratory, University of Berkeley, 7 Gauss Way, Berkeley, California 94720 (United States)

2013-12-15T23:59:59.000Z

155

Energetic Electrons Accelerated in Solar Particle Events Space Sciences Laboratory, University of Berkeley, CA 94720  

E-Print Network [OSTI]

, University of Berkeley, CA 94720 Abstract. New measurements of energetic solar electrons from the WIND and ACE/WIND should provide new insights into the origins of energetic solar particles. INTRODUCTIONEnergetic Electrons Accelerated in Solar Particle Events R. P. Lin Space Sciences Laboratory

California at Berkeley, University of

156

Unphysical kinetic effects in particle-in-cell modeling of laser wakefield accelerators Estelle Cormier-Michel,1,2  

E-Print Network [OSTI]

Unphysical kinetic effects in particle-in-cell modeling of laser wakefield accelerators Estelle of laser wakefield accelerators using particle-in-cell codes are investigated. A dark current free laser wakefield accelerator stage, in which no trapping of background plasma electrons into the plasma wave should

Geddes, Cameron Guy Robinson

157

String black hole: Can it be a particle accelerator ?  

E-Print Network [OSTI]

In this paper we have studied the possibility of the center-of-mass energy of two particles colliding near the horizon of a static charged black hole in string theory. Various cases corresponding to the electric charge and the angular momentum of the particles were considered. The studies were done for the general black hole as well as for the extreme black hole. There were two scenarios where the center-of-mass energy reach very large values if the appropriate properties of the particles are chosen.

Sharmanthie Fernando

2014-08-21T23:59:59.000Z

158

Accelerator Physics Accelerators form the backbone of SLAC's on-site experimental program. Research at SLAC  

E-Print Network [OSTI]

#12;Accelerator Physics Accelerators form the backbone of SLAC's on-site experimental program. Research at SLAC is continually improving accelerators, both here and at other laboratories, and paving the way for a new generation of particle acceleration technology. SLAC's famous linear accelerator

Wechsler, Risa H.

159

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

E-Print Network [OSTI]

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...

Olmi, Barbara; Amato, Elena; Bucciantini, Niccolň

2015-01-01T23:59:59.000Z

160

Designing double-gap linear accelerators for a wide mass range  

SciTech Connect (OSTI)

For applications like ion implantation, rf linacs using double-gap structures with external resonators can be used because they are practical at low frequencies. However, since the two gaps associated with a given resonator cannot be individually phased, it is not obvious how to build a linac that can efficiently accelerate particles having different mass/charge ratios. This paper describes the beam dynamics of double-gap rf linacs and shows how to maximize the range of mass/charge ratios. The theory also tells one how to rescale a linac tune (i.e., reset the voltages and phases) so that a new particle, having a different mass or charge, will behave similarly to the original particle.

Lysenko, W.P.; Wadlinger, E.A.; Rusnak, B.; Krawczyk, F. [Los Alamos National Lab., NM (United States); Saadatmand, K.; Wan, Z. [Eaton Corp., Beverly, MA (United States)

1998-12-31T23:59:59.000Z

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


161

Application to Particle Accelerator Beam Stabilization Glenn Decker  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmesApplication Acceleration on CurrentPDSLin to thethe

162

Automated detection and analysis of particle beams in laser-plasma accelerator simulations  

SciTech Connect (OSTI)

Numerical simulations of laser-plasma wakefield (particle) accelerators model the acceleration of electrons trapped in plasma oscillations (wakes) left behind when an intense laser pulse propagates through the plasma. The goal of these simulations is to better understand the process involved in plasma wake generation and how electrons are trapped and accelerated by the wake. Understanding of such accelerators, and their development, offer high accelerating gradients, potentially reducing size and cost of new accelerators. One operating regime of interest is where a trapped subset of electrons loads the wake and forms an isolated group of accelerated particles with low spread in momentum and position, desirable characteristics for many applications. The electrons trapped in the wake may be accelerated to high energies, the plasma gradient in the wake reaching up to a gigaelectronvolt per centimeter. High-energy electron accelerators power intense X-ray radiation to terahertz sources, and are used in many applications including medical radiotherapy and imaging. To extract information from the simulation about the quality of the beam, a typical approach is to examine plots of the entire dataset, visually determining the adequate parameters necessary to select a subset of particles, which is then further analyzed. This procedure requires laborious examination of massive data sets over many time steps using several plots, a routine that is unfeasible for large data collections. Demand for automated analysis is growing along with the volume and size of simulations. Current 2D LWFA simulation datasets are typically between 1GB and 100GB in size, but simulations in 3D are of the order of TBs. The increase in the number of datasets and dataset sizes leads to a need for automatic routines to recognize particle patterns as particle bunches (beam of electrons) for subsequent analysis. Because of the growth in dataset size, the application of machine learning techniques for scientific data mining is increasingly considered. In plasma simulations, Bagherjeiran et al. presented a comprehensive report on applying graph-based techniques for orbit classification. They used the KAM classifier to label points and components in single and multiple orbits. Love et al. conducted an image space analysis of coherent structures in plasma simulations. They used a number of segmentation and region-growing techniques to isolate regions of interest in orbit plots. Both approaches analyzed particle accelerator data, targeting the system dynamics in terms of particle orbits. However, they did not address particle dynamics as a function of time or inspected the behavior of bunches of particles. Ruebel et al. addressed the visual analysis of massive laser wakefield acceleration (LWFA) simulation data using interactive procedures to query the data. Sophisticated visualization tools were provided to inspect the data manually. Ruebel et al. have integrated these tools to the visualization and analysis system VisIt, in addition to utilizing efficient data management based on HDF5, H5Part, and the index/query tool FastBit. In Ruebel et al. proposed automatic beam path analysis using a suite of methods to classify particles in simulation data and to analyze their temporal evolution. To enable researchers to accurately define particle beams, the method computes a set of measures based on the path of particles relative to the distance of the particles to a beam. To achieve good performance, this framework uses an analysis pipeline designed to quickly reduce the amount of data that needs to be considered in the actual path distance computation. As part of this process, region-growing methods are utilized to detect particle bunches at single time steps. Efficient data reduction is essential to enable automated analysis of large data sets as described in the next section, where data reduction methods are steered to the particular requirements of our clustering analysis. Previously, we have described the application of a set of algorithms to automate the data analys

Ushizima, Daniela Mayumi; Geddes, C.G.; Cormier-Michel, E.; Bethel, E. Wes; Jacobsen, J.; Prabhat, ,; R.ubel, O.; Weber, G,; Hamann, B.

2010-05-21T23:59:59.000Z

163

150-MW S-band klystron program at the Stanford Linear Accelerator Center  

SciTech Connect (OSTI)

Two S-Band klystrons operating at 150 MW have been designed, fabricated and tested at the Stanford Linear Accelerator Center (SLAC) during the past two years for use in an experimental accelerator at Deutsches Elektronen-Synchrotron (DESY) in Hamburg, Germany. Both klystrons operate at the design power, 60 Hz repetition rate, 3 {micro}s pulsewidth, with an efficiency {gt} 40%, and agreement between the experimental results and simulations is excellent. The 535 kV, 700 A electron gun was tested by constructing a solenoidal focused beam stick which identified a source of oscillation, subsequently engineered out of the klystron guns. Design of the beam stick and the two klystrons is discussed, along with observation and suppression of spurious oscillations. Differences in design and the resulting performance of the Klystrons is emphasized.

Sprehn, D.; Caryotakis, G.; Phillips, R.M.

1996-07-01T23:59:59.000Z

164

Assessing Risk in Costing High-energy Accelerators: from Existing Projects to the Future Linear Collider  

E-Print Network [OSTI]

High-energy accelerators are large projects funded by public money, developed over the years and constructed via major industrial contracts both in advanced technology and in more conventional domains such as civil engineering and infrastructure, for which they often constitute one-of markets. Assessing their cost, as well as the risk and uncertainty associated with this assessment is therefore an essential part of project preparation and a justified requirement by the funding agencies. Stemming from the experience with large circular colliders at CERN, LEP and LHC, as well as with the Main Injector, the Tevatron Collider Experiments and Accelerator Upgrades, and the NOvA Experiment at Fermilab, we discuss sources of cost variance and derive cost risk assessment methods applicable to the future linear collider, through its two technical approaches for ILC and CLIC. We also address disparities in cost risk assessment imposed by regional differences in regulations, procedures and practices.

Lebrun, Philippe

2010-01-01T23:59:59.000Z

165

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

SciTech Connect (OSTI)

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.

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)

2013-10-10T23:59:59.000Z

166

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

SciTech Connect (OSTI)

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.

Lin, M.-W.; Jovanovic, I. [Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

2012-11-15T23:59:59.000Z

167

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

SciTech Connect (OSTI)

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.

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

1999-09-20T23:59:59.000Z

168

Particle acceleration by Majumdar-Papapetrou di-hole  

E-Print Network [OSTI]

We explore the multi-black hole spacetimes from the perspective of the ultra-high energy particle collisions. Such a discussion is limited to the spacetimes containing a single black hole so far. We deal with the Majumdar-Papapetrou solution representing a system consisting of two identical black holes in the equilibrium. In order to identify the conditions suitable for the process of high energy collisions, we consider particles confined to move on the equatorial plane towards the axis of symmetry with the zero angular momentum. We consider collision between the particles moving in opposite directions at the location midway between the black holes on the axis. We show that the center of mass energy of collision between the particles increases with the decrease in the separation between the black holes and shows divergence in the limit where the separation goes to zero. We estimate the size of the region close to the central point on the equatorial plane where it would be possible to have high energy collisions and show that this region has a reasonably large spatial extent. We further explore the process of high energy collisions with the general geodesics with arbitrary angular momentum on the equatorial plane away from the central point. Although in this paper we deal with theMajumdar-Papapetrou spacetime which serves as a toy example representing multiple black holes, we speculate on the possibility that the ultra-high energy collisions would also occur in the more general setting like colliding black holes, when distance between the black holes is extremely small, which can in principle be verified in the numerical relativity simulations.

Mandar Patil; Pankaj S. Joshi

2014-09-03T23:59:59.000Z

169

Particle acceleration in sub-cycle optical cells  

E-Print Network [OSTI]

A single laser pulse with spot size smaller than half its wavelength ($w_0 particles. In this paper, we discuss the properties of an optical cell consisting of $N$ sub-cycle pulses that propagate in the direction perpendicular to the electron motion. We show that the energy gain produced by the cell is proportional to $N$ and it is sizable even for $\\mathcal{O}(1\\mathrm{~TW})$ pulses.

F. Terranova

2014-07-07T23:59:59.000Z

170

A MODEL FOR THE ESCAPE OF SOLAR-FLARE-ACCELERATED PARTICLES  

SciTech Connect (OSTI)

We address the problem of how particles are accelerated by solar flares can escape into the heliosphere on timescales of an hour or less. Impulsive solar energetic particle (SEP) bursts are generally observed in association with so-called eruptive flares consisting of a coronal mass ejection (CME) and a flare. These fast SEPs are believed to be accelerated directly by the flare, rather than by the CME shock. However, the precise mechanism by which the particles are accelerated remains controversial. Regardless of the origin of the acceleration, the particles should remain trapped in the closed magnetic fields of the coronal flare loops and the ejected flux rope, given the magnetic geometry of the standard eruptive-flare model. In this case, the particles would reach the Earth only after a delay of many hours to a few days (coincident with the bulk ejecta arriving at Earth). We propose that the external magnetic reconnection intrinsic to the breakout model for CME initiation can naturally account for the prompt escape of flare-accelerated energetic particles onto open interplanetary magnetic flux tubes. We present detailed 2.5-dimensional magnetohydrodynamic simulations of a breakout CME/flare event with a background isothermal solar wind. Our calculations demonstrate that if the event occurs sufficiently near a coronal-hole boundary, interchange reconnection between open and closed fields can occur. This process allows particles from deep inside the ejected flux rope to access solar wind field lines soon after eruption. We compare these results to standard observations of impulsive SEPs and discuss the implications of the model on further observations and calculations.

Masson, S.; Antiochos, S. K. [Space Weather Laboratory, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); DeVore, C. R., E-mail: sophie.masson@nasa.gov [Laboratory for Computational Physics and Fluid Dynamics, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375 (United States)

2013-07-10T23:59:59.000Z

171

Comparison of test particle acceleration in torsional spine and fan reconnection regimes  

SciTech Connect (OSTI)

Magnetic reconnection is a common phenomenon taking place in astrophysical and space plasmas, especially in solar flares which are rich sources of highly energetic particles. Torsional spine and fan reconnections are important mechanisms proposed for steady-state three-dimensional null-point reconnection. By using the magnetic and electric fields for these regimes, we numerically investigate the features of test particle acceleration in both regimes with input parameters for the solar corona. By comparison, torsional spine reconnection is found to be more efficient than torsional fan reconnection in an acceleration of a proton to a high kinetic energy. A proton can gain as high as 100?MeV of relativistic kinetic energy within only a few milliseconds. Moreover, in torsional spine reconnection, an accelerated particle can escape either along the spine axis or on the fan plane depending on its injection position. However, in torsional fan reconnection, the particle is only allowed to accelerate along the spine axis. In addition, in both regimes, the particle's trajectory and final kinetic energy depend on the injection position but adopting either spatially uniform or non-uniform localized plasma resistivity does not much influence the features of trajectory.

Hosseinpour, M., E-mail: hosseinpour@tabrizu.ac.ir; Mehdizade, M.; Mohammadi, M. A. [Plasma Physics Department, University of Tabriz, Tabriz (Iran, Islamic Republic of)

2014-10-15T23:59:59.000Z

172

IPAC15 Jefferson Lab - International Particle Accelerator Conference 2015  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching. | EMSLthe U.S. DOEInternational Particle

173

IPAC15 Jefferson Lab - International Particle Accelerator Conference 2015  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching. | EMSLthe U.S. DOEInternational ParticleScope of

174

IPAC15 Jefferson Lab - International Particle Accelerator Conference 2015  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching. | EMSLthe U.S. DOEInternational ParticleScope

175

Intraoperative radiation therapy using mobile electron linear accelerators: Report of AAPM Radiation Therapy Committee Task Group No. 72  

SciTech Connect (OSTI)

Intraoperative radiation therapy (IORT) has been customarily performed either in a shielded operating suite located in the operating room (OR) or in a shielded treatment room located within the Department of Radiation Oncology. In both cases, this cancer treatment modality uses stationary linear accelerators. With the development of new technology, mobile linear accelerators have recently become available for IORT. Mobility offers flexibility in treatment location and is leading to a renewed interest in IORT. These mobile accelerator units, which can be transported any day of use to almost any location within a hospital setting, are assembled in a nondedicated environment and used to deliver IORT. Numerous aspects of the design of these new units differ from that of conventional linear accelerators. The scope of this Task Group (TG-72) will focus on items that particularly apply to mobile IORT electron systems. More specifically, the charges to this Task Group are to (i) identify the key differences between stationary and mobile electron linear accelerators used for IORT (ii) describe and recommend the implementation of an IORT program within the OR environment, (iii) present and discuss radiation protection issues and consequences of working within a nondedicated radiotherapy environment, (iv) describe and recommend the acceptance and machine commissioning of items that are specific to mobile electron linear accelerators, and (v) design and recommend an efficient quality assurance program for mobile systems.

Sam Beddar, A.; Biggs, Peter J.; Chang Sha; Ezzell, Gary A.; Faddegon, Bruce A.; Hensley, Frank W.; Mills, Michael D. [Department of Radiation Physics, Division of Radiation Oncology, Unit 94, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Department of Radiation Oncology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599 (United States); Department of Radiation Oncology, Mayo Clinic Scottsdale, Scottsdale, Arizona 85259 (United States); Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143 (United States); Department of Radiation Oncology, University of Heidelberg, 69120 Heidelberg (Germany); Department of Radiation Oncology, James Graham Brown Cancer Center, Louisville, Kentucky 40202 (United States)

2006-05-15T23:59:59.000Z

176

Extragalactic circuits, transmission lines, and CR particle acceleration  

E-Print Network [OSTI]

A non-negligible fraction of a Supermassive Black Hole's (SMBH) rest mass energy gets transported into extragalactic space by a remarkable process in jets which are incompletely understood. What are the physical processes which transport this energy? It is likely that the energy flows electromagnetically, rather than via a particle beam flux. The deduced electromagnetic fields may produce particles of energy as high as $\\sim 10^{20}$ eV. The energetics of SMBH accretion disk models and the electromagnetic energy transfer imply that a SMBH should generate a $10^{18} - 10^{19}$ Amp\\`eres current close to the black hole and its accretion disk. We describe the so far best observation-based estimate of the magnitude of the current flow along the axis of the jet extending from the nucleus of the active galaxy in 3C303. The current is measured to be $I \\sim 10^{18}$ Amp\\`eres at $\\sim 40$ kpc away from the AGN. This indicates that organized current flow remains intact over multi-kpc distances. The electric current $...

Kronberg, Philipp P

2014-01-01T23:59:59.000Z

177

Noninterceptive method to measure longitudinal Twiss parameters of a beam in a hadron linear accelerator using beam position monitors  

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

A new method of measuring of the rms longitudinal Twiss parameters of a beam in linear accelerators is presented. It is based on using sum signals from beam position monitors sensitive to the longitudinal charge distribution in the bunch. The applicability of the method is demonstrated on the superconducting section of the Oak Ridge Spallation Neutron Source linear accelerator. The results are compared to a direct measurement of the bunch longitudinal profiles using an interceptive bunch shape monitor in the linac warm section of the same accelerator. Limitations of the method are discussed. The method is fast and simple, and can be used to obtain the initial parameters for the longitudinal matching in linear accelerators where interceptive diagnostics are not desirable.

Shishlo, A.; Aleksandrov, A.

2013-06-01T23:59:59.000Z

178

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. Geddes LBNL Min Chen LBNL Estelle Cormier-Michel Tech-X Corp. E. W. Bethel LBNL x(x106 ) 2000 4000

179

Small scale energy release and the acceleration and transport of energetic particles  

E-Print Network [OSTI]

Small scale energy release and the acceleration and transport of energetic particles Hugh Hudson1, and of their radio emission mechanisms. The RHESSI3 results are the most distinctive in this time frame observatory) 4 Very Large Array (Socorro, New Mexico) 5 Nobeyama Radio Heliograph (Nobeyama, Japan) 6

Hudson, Hugh

180

Particle-In-Cell Modeling of Plasma-Based Accelerators in Two and Three Dimensions  

E-Print Network [OSTI]

In this dissertation, a fully object-oriented, fully relativistic, multi-dimensional Particle-In-Cell code was developed and applied to answer key questions in plasma-based accelerator research. The simulations increase the understanding of the processes in laser plasma and beam-plasma interaction, allow for comparison with experiments, and motivate the development of theoretical models. The simulations support the idea that the injection of electrons in a plasma wave by using a transversely propagating laser pulse is possible. The beam parameters of the injected electrons found in the simulations compare reasonably with beams produced by conventional methods and therefore laser injection is an interesting concept for future plasma-based accelerators. Simulations of the optical guiding of a laser wakefield driver in a parabolic plasma channel support the idea that electrons can be accelerated over distances much longer than the Rayleigh length in a channel. Simulations of plasma wakefield acceleration in the ...

Hemker, Roy G

2015-01-01T23:59:59.000Z

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


181

Coherent States of Accelerated Relativistic Quantum Particles, Vacuum Radiation and the Spontaneous Breakdown of the Conformal SU(2,2) Symmetry  

E-Print Network [OSTI]

We give a quantum mechanical description of accelerated relativistic particles in the framework of Coherent States (CS) of the (3+1)-dimensional conformal group SU(2,2), with the role of accelerations played by special conformal transformations and with the role of (proper) time translations played by dilations. The accelerated ground state $\\tilde\\phi_0$ of first quantization is a CS of the conformal group. We compute the distribution function giving the occupation number of each energy level in $\\tilde\\phi_0$ and, with it, the partition function Z, mean energy E and entropy S, which resemble that of an "Einstein Solid". An effective temperature T can be assigned to this "accelerated ensemble" through the thermodynamic expression dE/dS, which leads to a (non linear) relation between acceleration and temperature different from Unruh's (linear) formula. Then we construct the corresponding conformal-SU(2,2)-invariant second quantized theory and its spontaneous breakdown when selecting Poincar\\'e-invariant degenerated \\theta-vacua (namely, coherent states of conformal zero modes). Special conformal transformations (accelerations) destabilize the Poincar\\'e vacuum and make it to radiate.

M. Calixto; E. Perez-Romero; V. Aldaya

2010-12-21T23:59:59.000Z

182

accelerated carbon ion: Topics by E-print Network  

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

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...

183

Compact accelerator for medical therapy  

DOE Patents [OSTI]

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.

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

2010-05-04T23:59:59.000Z

184

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

SciTech Connect (OSTI)

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.

Gontikakis, C.; Efthymiopoulos, C.; Georgoulis, M. K. [Research Center for Astronomy and Applied Mathematics, Academy of Athens, Soranou Efessiou 4, 11528 Athens (Greece); Patsourakos, S. [Section of Astro-Geophysics, Department of Physics, University of Ioannina, 45110 Ioannina (Greece); Anastasiadis, A., E-mail: cgontik@academyofathens.gr [National Observatory of Athens, Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, GR-15236, Palaia Penteli (Greece)

2013-07-10T23:59:59.000Z

185

Particle-In-Cell Simulation of Electron Acceleration in Solar Coronal Jets  

E-Print Network [OSTI]

We investigate electron acceleration resulting from 3D magnetic reconnection between an emerging, twisted magnetic flux rope and a pre-existing weak, open magnetic field. We first follow the rise of an unstable, twisted flux tube with a resistive MHD simulation where the numerical resolution is enhanced by using fixed mesh refinement. As in previous MHD investigations of similar situations the rise of the flux tube into the pre-existing inclined coronal magnetic field results in the formation of a solar coronal jet. A snapshot of the MHD model is then used as an initial and boundary condition for a particle-in-cell simulation, using up to half a billion cells and over 20 billion charged particle. Particle acceleration occurs mainly in the reconnection current sheet, with accelerated electrons displaying a power law dN/dE distribution with an index of about -1.65. The main acceleration mechanism is a systematic electric field, striving to maintaining the electric current in the current sheet against losses cau...

Baumann, G

2012-01-01T23:59:59.000Z

186

Thermophoretic and ponderomotive forces in a linear cluster of particles Yu. Dolinsky* and T. Elperin  

E-Print Network [OSTI]

Thermophoretic and ponderomotive forces in a linear cluster of particles Yu. Dolinsky* and T; published 21 November 2001 We investigate amplification of thermophoretic and ponderomotive forces caused fluid, and the thermophoretic force when the particles remain stationary due to the applied constraint

Elperin, Tov

187

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

DOE Patents [OSTI]

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.

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

1982-01-01T23:59:59.000Z

188

PARTICLE ACCELERATION IN FRAGMENTING PERIODIC RECONNECTING CURRENT SHEETS IN SOLAR FLARES  

SciTech Connect (OSTI)

Proton and electron acceleration in a fragmenting periodic current sheet (CS) is investigated, based on the forced magnetic reconnection scenario. The aim is to understand the role of CS fragmentation in high-energy beam generation in solar flares. We combine magnetohydrodynamics and test-particle models to consider particle trajectories consistent with a time-dependent reconnection model. It is shown that accelerated particles in such a model form two distinct populations. Protons and electrons moving in open magnetic field have energy spectra that are a combination of the initial Maxwellian distribution and a power-law high-energy (E>20 keV) part. The second population contains particles moving in a closed magnetic field around O-points. These particles move predominantly along the guiding field and their energies fall within quite a narrow range between {approx}1 MeV and {approx}10 MeV. It is also found that particles moving in an open magnetic field have a considerably wider pitch-angle distribution.

Gordovskyy, M.; Browning, P. K.; Vekstein, G. E., E-mail: mykola.gordovskyy@manchester.ac.u [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)

2010-09-10T23:59:59.000Z

189

3-D Model of Broadband Emission from Supernova Remnants Undergoing Non-linear Diffusive Shock Acceleration  

SciTech Connect (OSTI)

We present a 3-dimensional model of supernova remnants (SNRs) where the hydrodynamical evolution of the remnant is modeled consistently with nonlinear diffusive shock acceleration occurring at the outer blast wave. The model includes particle escape and diffusion outside of the forward shock, and particle interactions with arbitrary distributions of external ambient material, such as molecular clouds. We include synchrotron emission and cooling, bremsstrahlung radiation, neutral pion production, inverse-Compton (IC), and Coulomb energy-loss. Boardband spectra have been calculated for typical parameters including dense regions of gas external to a 1000 year old SNR. In this paper, we describe the details of our model but do not attempt a detailed fit to any specific remnant. We also do not include magnetic field amplification (MFA), even though this effect may be important in some young remnants. In this first presentation of the model we don't attempt a detailed fit to any specific remnant. Our aim is to develop a flexible platform, which can be generalized to include effects such as MFA, and which can be easily adapted to various SNR environments, including Type Ia SNRs, which explode in a constant density medium, and Type II SNRs, which explode in a pre-supernova wind. When applied to a specific SNR, our model will predict cosmic-ray spectra and multi-wavelength morphology in projected images for instruments with varying spatial and spectral resolutions. We show examples of these spectra and images and emphasize the importance of measurements in the hard X-ray, GeV, and TeV gamma-ray bands for investigating key ingredients in the acceleration mechanism, and for deducing whether or not TeV emission is produced by IC from electrons or pion-decay from protons.

Lee, Shiu-Hang; Kamae, Tuneyoshi; Ellison, Donald C.

2008-07-02T23:59:59.000Z

190

Precision measurement of a particle mass at the linear collider  

SciTech Connect (OSTI)

Precision measurement of the stop mass at the ILC is done in a method based on cross-sections measurements at two different center-of-mass energies. This allows to minimize both the statistical and systematic errors. In the framework of the MSSM, a light stop, compatible with electro-weak baryogenesis, is studied in its decay into a charm jet and neutralino, the Lightest Supersymmetric Particle (LSP), as a candidate of dark matter. This takes place for a small stop-neutralino mass difference.

Milstene, C.; /Fermilab; Freitas, A.; /Zurich U.; Schmitt, M.; /Northwestern U.; Sopczak, A.; /Lancaster U.

2007-06-01T23:59:59.000Z

191

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

SciTech Connect (OSTI)

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).

NONE

1995-08-01T23:59:59.000Z

192

Status of materials handbooks for particle accelerator and nuclear reactor applications  

SciTech Connect (OSTI)

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.

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

2008-01-01T23:59:59.000Z

193

Application of High-performance Visual Analysis Methods to Laser Wakefield Particle Acceleration Data  

SciTech Connect (OSTI)

Our work combines and extends techniques from high-performance scientific data management and visualization to enable scientific researchers to gain insight from extremely large, complex, time-varying laser wakefield particle accelerator simulation data. We extend histogram-based parallel coordinates for use in visual information display as well as an interface for guiding and performing data mining operations, which are based upon multi-dimensional and temporal thresholding and data subsetting operations. To achieve very high performance on parallel computing platforms, we leverage FastBit, a state-of-the-art index/query technology, to accelerate data mining and multi-dimensional histogram computation. We show how these techniques are used in practice by scientific researchers to identify, visualize and analyze a particle beam in a large, time-varying dataset.

Rubel, Oliver; Prabhat, Mr.; Wu, Kesheng; Childs, Hank; Meredith, Jeremy; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Ahern, Sean; Weber, Gunther H.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

2008-08-28T23:59:59.000Z

194

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]

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

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

2008-01-01T23:59:59.000Z

195

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

E-Print Network [OSTI]

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...

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

2015-01-01T23:59:59.000Z

196

Novel Methods in the Particle-In-Cell Accelerator Code-Framework Warp  

SciTech Connect (OSTI)

The Particle-In-Cell (PIC) Code-Framework Warp is being developed by the Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) to guide the development of accelerators that can deliver beams suitable for high energy density experiments and implosion of inertial fusion capsules. It is also applied in various areas outside the Heavy Ion Fusion program to the study and design of existing and next-generation high-energy accelerators, including the study of electron cloud effects and laser wakefield acceleration for example. This paper presents an overview of Warp’s capabilities, summarizing recent original numerical methods that were developed by the HIFS-VNL (including Particle-In-Cell with Adaptive Mesh Refinement, a large-timestep “drift-Lorentz” mover for arbitrarily magnetized species, a relativistic Lorentz invariant leapfrog particle pusher, simulations in Lorentz boosted frames, an electromagnetic solver with tunable numerical dispersion and efficient stride20 based digital filtering), with great emphasis on the description of the mesh refinement capability. Selected examples of applications of the methods to the abovementioned fields are given.

Vay, J. -L.; Grote, D. P.; Cohen, R. H.; Friedman, A.; Grote, D. P.; Cohen, R. H.; Friedman, A.

2011-09-01T23:59:59.000Z

197

Novel X-Ray Imaging Opportunities for the RPI Linear Accelerator's Tunable, Quasi-monochromatic X-ray Source  

E-Print Network [OSTI]

Novel X-Ray Imaging Opportunities for the RPI Linear Accelerator's Tunable, Quasi-monochromatic X-ray of an intense, tunable, polarized, and quasi-monochromatic X-ray source has been ongoing at Rensselaer Polytechnic Institute since 2001 [1, 2, 3, 4, 5, 6]. This X-ray source, known as Parametric X-rays (PXR

Danon, Yaron

198

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)

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.

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

2011-09-07T23:59:59.000Z

199

Course Notes: United States Particle Accelerator School Beam Physics with Intense Space-Charge  

SciTech Connect (OSTI)

The purpose of this course is to provide a comprehensive introduction to the physics of beams with intense space charge. This course is suitable for graduate students and researchers interested in accelerator systems that require sufficient high intensity where mutual particle interactions in the beam can no longer be neglected. This course is intended to give the student a broad overview of the dynamics of beams with strong space charge. The emphasis is on theoretical and analytical methods of describing the acceleration and transport of beams. Some aspects of numerical and experimental methods will also be covered. Students will become familiar with standard methods employed to understand the transverse and longitudinal evolution of beams with strong space charge. The material covered will provide a foundation to design practical architectures. In this course, we will introduce you to the physics of intense charged particle beams, focusing on the role of space charge. The topics include: particle equations of motion, the paraxial ray equation, and the Vlasov equation; 4-D and 2-D equilibrium distribution functions (such as the Kapchinskij-Vladimirskij, thermal equilibrium, and Neuffer distributions), reduced moment and envelope equation formulations of beam evolution; transport limits and focusing methods; the concept of emittance and the calculation of its growth from mismatches in beam envelope and from space-charge non-uniformities using system conservation constraints; the role of space-charge in producing beam halos; longitudinal space-charge effects including small amplitude and rarefaction waves; stable and unstable oscillation modes of beams (including envelope and kinetic modes); the role of space charge in the injector; and algorithms to calculate space-charge effects in particle codes. Examples of intense beams will be given primarily from the ion and proton accelerator communities with applications from, for example, heavy-ion fusion, spallation neutron sources, nuclear waste transmutation, etc.

Barnard, J.J.; Lund, S.M.

2008-05-30T23:59:59.000Z

200

An intra-oral cone for an 18 MeV linear accelerator  

SciTech Connect (OSTI)

A set of intra-oral cones has been constructed for electron beam therapy from a linear accelerator. The 4 cm x 4 cm treatment accessory provided with this machine was modified by simply removing the lower collimator and replacing it with a brass plate into which all the cones can fit, so that they are easily interchangeable. Six circular cones, with diameters ranging from 27 mm to 45 mm, plus two elliptical cones are currently in use. A light field system has been built that fits into the acrylic compartment directly above the base, and provides a clear, well-illuminated view of the treatment field. The dosimetry for these cones shows that the percent depth dose curve for a 41 mm diameter field is the same as that obtained with the 4 cm x 4 cm treatment accessory, and that the isodose curves are very similar. This intra-oral cone system has been in operation for over two years and we have found it very useful in boosting the dose to specific primary lesions in the oral cavity, for example, oral tongue, floor of mouth, retromolar trigone, and soft palate.

Biggs, P.J.; Wang, C.C.

1982-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "linear particle accelerator" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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201

GAMMA-RAY EMISSION OF ACCELERATED PARTICLES ESCAPING A SUPERNOVA REMNANT IN A MOLECULAR CLOUD  

SciTech Connect (OSTI)

We present a model of gamma-ray emission from core-collapse supernovae (SNe) originating from the explosions of massive young stars. The fast forward shock of the supernova remnant (SNR) can accelerate particles by diffusive shock acceleration (DSA) in a cavern blown by a strong, pre-SN stellar wind. As a fundamental part of nonlinear DSA, some fraction of the accelerated particles escape the shock and interact with a surrounding massive dense shell producing hard photon emission. To calculate this emission, we have developed a new Monte Carlo technique for propagating the cosmic rays (CRs) produced by the forward shock of the SNR, into the dense, external material. This technique is incorporated in a hydrodynamic model of an evolving SNR which includes the nonlinear feedback of CRs on the SNR evolution, the production of escaping CRs along with those that remain trapped within the remnant, and the broadband emission of radiation from trapped and escaping CRs. While our combined CR-hydro-escape model is quite general and applies to both core collapse and thermonuclear SNe, the parameters we choose for our discussion here are more typical of SNRs from very massive stars whose emission spectra differ somewhat from those produced by lower mass progenitors directly interacting with a molecular cloud.

Ellison, 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: byk@astro.ioffe.ru [Ioffe Institute for Physics and Technology, 194021 St. Petersburg (Russian Federation)

2011-04-20T23:59:59.000Z

202

Review of Heavy-ion Induced Desorption Studies for Particle Accelerators  

E-Print Network [OSTI]

During high-intensity heavy-ion operation of several particle accelerators worldwide, large dynamic pressure rises of orders of magnitude were caused by lost beam ions that impacted under grazing angle onto the vacuum chamber walls. This ion-induced desorption, observed, for example, at CERN, GSI, and BNL, can seriously limit the ion intensity, luminosity, and beam lifetime of the accelerator. For the heavyion program at CERN's Large Hadron Collider collisions between beams of fully stripped lead (208Pb82+) ions with a beam energy of 2.76 TeV/u and a nominal luminosity of 10**27 cm**-2 s**-1 are foreseen. The GSI future project FAIR (Facility for Antiproton and Ion Research) aims at a beam intensity of 10**12 uranium (238U28+) ions per second to be extracted from the synchrotron SIS18. Over the past years an experimental effort has been made to study the observed dynamic vacuum degradations, which are important to understand and overcome for present and future particle accelerators. The paper reviews the resu...

Mahner, E

2008-01-01T23:59:59.000Z

203

Particle accelerator control and data acquisition in the context of VAX/VMS  

SciTech Connect (OSTI)

The Los Alamos Meson Physics Facility (LAMPF) Control System monitors and controls a linear accelerator through more than 10,000 widely disparate I/O devices. The heart of the Control System software is the Data System, which provides a uniform application program interface based on symbolic device names. In many ways the Data System parallels the VAX/VMS Record Management Services (RMS) in its needs for asynchronous operations, protection, and locks for multiprocess interactions. Since the accelerator control hardware is continually changing, it is important that privileged code be kept to a minimum or be testable in a non-privileged environment. This paper describes the LAMPF Data System design including the use of VAX/VMS user written system services (both kernel and supervisor mode), a user supplied image rundown routine, the VAX/VMS lock manager, and a large (3.5 Mbyte) protected global section.

Schaller, S.C.; Corley, J.K.

1983-01-01T23:59:59.000Z

204

FPGA-based Particle Recognition in the HADES Abstract--Modern FPGA technologies are often employed in nuclear and particle physics experimental facilities to accelerate  

E-Print Network [OSTI]

1 FPGA-based Particle Recognition in the HADES Experiment Abstract--Modern FPGA technologies-specific computation. We present the particle recognition computation for the HADES experiment in this article of commodity PCs for the HADES experiment. Index Terms--reconfigurable computing, FPGA accelerator, pattern

Jantsch, Axel

205

The colliding-wind binary WR140: the particle acceleration laboratory  

E-Print Network [OSTI]

WR+O star binary systems exhibit synchrotron emission arising from relativistic electrons accelerated where the wind of the WR star and that of its massive binary companion collide - the wind-collision region (WCR). These ``colliding-wind'' binaries (CWB), provide an excellent laboratory for the study of particle acceleration, with the same physical processes as observed in SNRs, but at much higher mass, photon and magnetic energy densities. WR140 is the best studied CWB, and high resolution radio observations permit a determination of several system parameters, particularly orbit inclination and distance, that are essential constraints for newly developed models of CWBs. We show a model fit to the radio data at orbital phase 0.9, and show how these models may be used to predict the high energy emission from WR140.

S. M. Dougherty; J. M. Pittard

2005-10-18T23:59:59.000Z

206

A GEOMETRIC DERIVATION OF THE LINEAR BOLTZMANN EQUATION FOR A PARTICLE INTERACTING WITH A  

E-Print Network [OSTI]

] the radiative transport equation in the spatially homogenous case. Later Ho, Landau and Wilkins studied in [29 Boltzmann equation was derived in the radiative transport limit by Bal, Papanicolaou and Ryzhik [5A GEOMETRIC DERIVATION OF THE LINEAR BOLTZMANN EQUATION FOR A PARTICLE INTERACTING WITH A GAUSSIAN

Paris-Sud XI, Université de

207

Design Considerations for Plasma Accelerators Driven by Lasers or Particle Beams  

E-Print Network [OSTI]

collider," in Advanced Accelerator Concepts, edited by C .Considerations for Plasma Accelerators Driven by Lasers orUSA Abstract. Plasma accelerators may be driven by the

Schroeder, C. B.

2011-01-01T23:59:59.000Z

208

E-Print Network 3.0 - atca-based linear accelerator Sample Search...  

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

University Collection: Engineering ; Physics 25 FPGA-based Particle Recognition in the HADES Abstract--Modern FPGA technologies are often employed in nuclear and particle physics...

209

Particle acceleration and transport in reconnecting twisted loops in a stratified atmosphere  

E-Print Network [OSTI]

Twisted coronal loops should be ubiquitous in the solar corona. Twisted magnetic fields contain excess magnetic energy, which can be released during magnetic reconnection, causing solar flares. The aim of this work is to investigate magnetic reconnection, and particle acceleration and transport in kink-unstable twisted coronal loops, with a focus on the effects of resistivity, loop geometry and atmospheric stratification. Another aim is to perform forward-modelling of bremsstrahlung emission and determine the structure of hard X-ray sources. We use a combination of magnetohydrodynamic (MHD) and test-particle methods. First, the evolution of the kinking coronal loop is considered using resistive MHD model, incorporating atmospheric stratification and loop curvature. Then, the obtained electric and magnetic fields and density distributions are used to calculate electron and proton trajectories using a guiding-centre approximation, taking into account Coulomb collisions. It is shown that electric fields in twist...

Gordovskyy, Mykola; Kontar, Eduard; Bian, Nicolas

2015-01-01T23:59:59.000Z

210

On Comparing the Quality of Head and Neck Imrt Plans Delivered with Two Different Linear Accelerator Manufacturers  

SciTech Connect (OSTI)

The purpose of this work was to determine whether 2 different types of linear accelerators manufacturers with similar MLC leaf widths deliver equivalent IMRT distributions for head and neck radiotherapy patients. In this study, plans delivered with Siemens linacs were re-optimized with an Elekta linac and vice versa. To test for significance, paired t-tests were computed to examine differences in target and normal tissue doses and monitor units. Dose distributions, dose-volume histograms, and dose to targets and normal tissues were found to be equivalent irrespective of the linac type. However, approximately 15% more monitor units were delivered when planned on the Elekta machine (p < 0.002). Both linear accelerators provide plans of comparable dosimetric quality; however, Elekta machines deliver slightly more monitor units than Siemens machines. This increase is likely due differences in geometric properties of the machine head designs, as modeled in the treatment planning system.

Basran, Parminder S., E-mail: pbasran@bccancer.bc.c [Department of Medical Physics, Odette Cancer Centre, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Balogh, Judith; Poon, Ian; MacKenzie, Robert [Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, Odette Cancer Centre, Toronto, Ontario (Canada); Chan, Timothy [Department of Medical Sciences, University of Western Ontario, Toronto, Ontario (Canada)

2011-04-01T23:59:59.000Z

211

LASER ACCELERATORS  

E-Print Network [OSTI]

UNIVERSITY OF CALIFORNIA Accelerator & Fusion Researchat the 1983 Particle Accelerator Conference, Santa Fe, NM,March 21-23, 1983 LASER ACCELERATORS A.M. Sessler TWO-WEEK

Sessler, A.M.

2008-01-01T23:59:59.000Z

212

Bulk ion acceleration and particle heating during magnetic reconnection in a laboratory plasma  

SciTech Connect (OSTI)

Bulk ion acceleration and particle heating during magnetic reconnection are studied in the collisionless plasma of the Magnetic Reconnection Experiment (MRX). The plasma is in the two-fluid regime, where the motion of the ions is decoupled from that of the electrons within the ion diffusion region. The reconnection process studied here is quasi-symmetric since plasma parameters such as the magnitude of the reconnecting magnetic field, the plasma density, and temperature are compatible on each side of the current sheet. Our experimental data show that the in-plane (Hall) electric field plays a key role in ion heating and acceleration. The electrostatic potential that produces the in-plane electric field is established by electrons that are accelerated near the electron diffusion region. The in-plane profile of this electrostatic potential shows a “well” structure along the direction normal to the reconnection current sheet. This well becomes deeper and wider downstream as its boundary expands along the separatrices where the in-plane electric field is strongest. Since the in-plane electric field is 3–4 times larger than the out-of-plane reconnection electric field, it is the primary source of energy for the unmagnetized ions. With regard to ion acceleration, the Hall electric field causes ions near separatrices to be ballistically accelerated toward the outflow direction. Ion heating occurs as the accelerated ions travel into the high pressure downstream region. This downstream ion heating cannot be explained by classical, unmagnetized transport theory; instead, we conclude that ions are heated by re-magnetization of ions in the reconnection exhaust and collisions. Two-dimensional (2-D) simulations with the global geometry similar to MRX demonstrate downstream ion thermalization by the above mechanisms. Electrons are also significantly heated during reconnection. The electron temperature sharply increases across the separatrices and peaks just outside of the electron diffusion region. Unlike ions, electrons acquire energy mostly from the reconnection electric field, and the energy gain is localized near the X-point. However, the increase in the electron bulk flow energy remains negligible. These observations support the assertion that efficient electron heating mechanisms exist around the electron diffusion region and that the heat generated there is quickly transported along the magnetic field due to the high parallel thermal conductivity of electrons. Classical Ohmic dissipation based on the perpendicular Spitzer resistivity is too small to balance the measured heat flux, indicating the presence of anomalous electron heating.

Yoo, Jongsoo; Yamada, Masaaki; Ji, Hantao; Jara-Almonte, Jonathan; Myers, Clayton E. [Center for Magnetic Self-Organization, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Center for Magnetic Self-Organization, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2014-05-15T23:59:59.000Z

213

Commissioning of the Varian TrueBeam linear accelerator: A multi-institutional study  

SciTech Connect (OSTI)

Purpose: Latest generation linear accelerators (linacs), i.e., TrueBeam (Varian Medical Systems, Palo Alto, CA) and its stereotactic counterpart, TrueBeam STx, have several unique features, including high-dose-rate flattening-filter-free (FFF) photon modes, reengineered electron modes with new scattering foil geometries, updated imaging hardware/software, and a novel control system. An evaluation of five TrueBeam linacs at three different institutions has been performed and this work reports on the commissioning experience. Methods: Acceptance and commissioning data were analyzed for five TrueBeam linacs equipped with 120 leaf (5 mm width) MLCs at three different institutions. Dosimetric data and mechanical parameters were compared. These included measurements of photon beam profiles (6X, 6XFFF, 10X, 10XFFF, 15X), photon and electron percent depth dose (PDD) curves (6, 9, 12 MeV), relative photon output factors (Scp), electron cone factors, mechanical isocenter accuracy, MLC transmission, and dosimetric leaf gap (DLG). End-to-end testing and IMRT commissioning were also conducted. Results: Gantry/collimator isocentricity measurements were similar (0.27-0.28 mm), with overall couch/gantry/collimator values of 0.46-0.68 mm across the three institutions. Dosimetric data showed good agreement between machines. The average MLC DLGs for 6, 10, and 15 MV photons were 1.33 {+-} 0.23, 1.57 {+-} 0.24, and 1.61 {+-} 0.26 mm, respectively. 6XFFF and 10XFFF modes had average DLGs of 1.16 {+-} 0.22 and 1.44 {+-} 0.30 mm, respectively. MLC transmission showed minimal variation across the three institutions, with the standard deviation <0.2% for all linacs. Photon and electron PDDs were comparable for all energies. 6, 10, and 15 MV photon beam quality, %dd(10){sub x} varied less than 0.3% for all linacs. Output factors (Scp) and electron cone factors agreed within 0.27%, on average; largest variations were observed for small field sizes (1.2% coefficient of variation, 10 MV, 2 Multiplication-Sign 2 cm{sup 2}) and small cone sizes (<1% coefficient of variation, 6 Multiplication-Sign 6 cm{sup 2} cone), respectively. Conclusions: Overall, excellent agreement was observed in TrueBeam commissioning data. This set of multi-institutional data can provide comparison data to others embarking on TrueBeam commissioning, ultimately improving the safety and quality of beam commissioning.

Glide-Hurst, C.; Bellon, M.; Wen, N.; Zhao, B.; Chetty, I. J. [Department of Radiation Oncology, Henry Ford Health Systems, Detroit, Michigan 48202 (United States); Foster, R.; Speiser, M.; Solberg, T. [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas 75235 (United States); Altunbas, C.; Westerly, D.; Miften, M. [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States); Altman, M. [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States)

2013-03-15T23:59:59.000Z

214

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

SciTech Connect (OSTI)

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.

McDonald, R.J. (ed.)

1987-09-01T23:59:59.000Z

215

Quantum mechanics of a charged particle in a background magnetic field interacting with linearized gravitational waves  

E-Print Network [OSTI]

We consider the dynamics of a charged particle interacting with background electromagnetic field under the influence of linearized gravitational waves in the long wave-length and low-velocity limit. Following the prescription in \\cite{speli}, the system is quantized and the Hamiltonian is then solved by using standard algebraic iterative methods. The solution is in conformity with the classical analysis and shows the possibility of tuning the frequency by changing the magnetic field to set up resonance.

Sunandan Gangopadhyay; Anirban Saha

2012-04-02T23:59:59.000Z

216

Using X-ray observations to identify the particle acceleration mechanisms in VHE SNRs and "dark" VHE sources  

E-Print Network [OSTI]

Very high energy (VHE) gamma-ray observations have proven to be very successful in localizing Galactic acceleration sites of VHE particles. Observations of shell-type supernova remnants have confirmed that particles are accelerated to VHE energies in supernova blast waves; the interpretation of the gamma-ray data in terms of hadronic or leptonic particle components in these objects relies nevertheless strongly on input from X-ray observations. The largest identified Galactic VHE source class consists of pulsar wind nebulae, as detected in X-rays. Many of the remaining VHE sources remain however unidentified until now. With X-ray observations of these enigmatic "dark" objects one hopes to solve the following questions: What is the astrophysical nature of these sources? Are they predominantly electron or hadron accelerators? And what is their contribution to the overall cosmic ray energy budget? The paper aims to provide an overview over the identification status of the Galactic VHE source population.

G. Pühlhofer

2007-10-17T23:59:59.000Z

217

Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics  

E-Print Network [OSTI]

New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN -- the AWAKE experiment -- has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

AWAKE Collaboration; R. Assmann; R. Bingham; T. Bohl; C. Bracco; B. Buttenschon; A. Butterworth; A. Caldwell; S. Chattopadhyay; S. Cipiccia; E. Feldbaumer; R. A. Fonseca; B. Goddard; M. Gross; O. Grulke; E. Gschwendtner; J. Holloway; C. Huang; D. Jaroszynski; S. Jolly; P. Kempkes; N. Lopes; K. Lotov; J. Machacek; S. R. Mandry; J. W. McKenzie; M. Meddahi; B. L. Militsyn; N. Moschuering; P. Muggli; Z. Najmudin; T. C. Q. Noakes; P. A. Norreys; E. Oz; A. Pardons; A. Petrenko; A. Pukhov; K. Rieger; O. Reimann; H. Ruhl; E. Shaposhnikova; L. O. Silva; A. Sosedkin; R. Tarkeshian; R. M. G. N. Trines; T. Tuckmantel; J. Vieira; H. Vincke; M. Wing; G. Xia

2014-04-02T23:59:59.000Z

218

Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics  

E-Print Network [OSTI]

New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN -- the AWAKE experiment -- has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

Assmann, R; Bohl, T; Bracco, C; Buttenschon, B; Butterworth, A; Caldwell, A; Chattopadhyay, S; Cipiccia, S; Feldbaumer, E; Fonseca, R A; Goddard, B; Gross, M; Grulke, O; Gschwendtner, E; Holloway, J; Huang, C; Jaroszynski, D; Jolly, S; Kempkes, P; Lopes, N; Lotov, K; Machacek, J; Mandry, S R; McKenzie, J W; Meddahi, M; Militsyn, B L; Moschuering, N; Muggli, P; Najmudin, Z; Noakes, T C Q; Norreys, P A; Oz, E; Pardons, A; Petrenko, A; Pukhov, A; Rieger, K; Reimann, O; Ruhl, H; Shaposhnikova, E; Silva, L O; Sosedkin, A; Tarkeshian, R; Trines, R M G N; Tuckmantel, T; Vieira, J; Vincke, H; Wing, M; Xia, G

2014-01-01T23:59:59.000Z

219

Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics  

E-Print Network [OSTI]

New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN { the AWAKE experiment { has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

Assmann, R; Bohl, T; Bracco, C; Buttenschon, B; Butterworth, A; Caldwell, A; Chattopadhyay, S; Cipiccia, S; Feldbaumer, E; Fonseca, R A; Goddard, B; Gross, M; Grulke, O; Gschwendtner, E; Holloway, J; Huang, C; Jaroszynski, D; Jolly, S; Kempkes, P; Lopes, N; Lotov, K; Machacek, J; Mandry, S R; McKenzie, J W; Meddahi, M; Militsyn, B L; Moschuering, N; Muggli, P; Najmudin, Z; Noakes, T C Q; Norreys, P A; Oz, E; Pardons, A; Petrenko, A; Pukhov, A; Rieger, K; Reimann, O; Ruhl, H; Shaposhnikova, E; Silva, L O; Sosedkin, A; Tarkeshian, R; Trines, R M G N; Tuckmantel, T; Vieira, J; Vincke, H; Wing, M; Xia G , G

2014-01-01T23:59:59.000Z

220

Application of Atmospheric Plasma-Sprayed Ferrite Layers for Particle Accelerators  

E-Print Network [OSTI]

A common problem in all kinds of cavity-like structures in particle accelerators is the occurrence of RF-resonances. Typically, ferrite plates attached to the walls of such structures as diagnostic devices, kickers or collimators, are used to dampen those undesired modes. However, the heat transfer rate from these plates to the walls is rather limited. Brazing ferrite plates to the walls is not possible in most cases due to the different thermal expansion coefficients. To overcome those limitations, atmospheric plasma spraying techniques have been investigated. Ferrite layers with a thickness from 50 ?m to about 300 ?m can be deposited on metallic surfaces like stainless steel exhibiting good thermal contact and still reasonable absorption properties. In this paper the technological aspects of plasma deposition are discussed and results of specifically developed RF loss measurement procedures for such thin magnetically lossy layers on metal are presented.

Caspers, F; Federmann, S; Taborelli, M; Schulz, C; Bobzin, K; Wu, J

2013-01-01T23:59:59.000Z

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


221

Study of quality assurance regulations for linear accelerators in Korea: A comparison study between the current status in Korea and the international guidelines  

E-Print Network [OSTI]

Quality assurance (QA) for medical linear accelerators is indispensable for appropriate cancer treatment. Some international organizations and western advanced countries provide QA guidelines for linear accelerators. Currently, QA regulations for linear accelerators in Korean hospitals specify a system in which each hospital stipulates its independent hospital-based protocols for QA procedures (HP_QAPs) and conducts QA based on these HP_QAPs while regulatory authorities verify whether items under these HP_QAPs have been performed. However, because this regulatory method cannot guarantee the quality of universal treatment, and QA items with tolerance criteria are different in many hospitals, the presentation of standardized QA items and tolerance criteria is essential. In this study, QA items in HP_QAPs from various hospitals and those presented by international organizations. Concordance rates between QA items for linear accelerators that were presented by the aforementioned organizations and those currently ...

Lee, Hyunho; Jo, Yunhui; Yoon, Myonggeun

2015-01-01T23:59:59.000Z

222

Insights into the particle acceleration of a peculiar gamma -ray radio galaxy IC 310  

E-Print Network [OSTI]

IC 310 has recently been identified as a gamma-ray emitter based on observations at GeV energies with Fermi-LAT and at very high energies (VHE, E > 100 GeV) with the MAGIC telescopes. Despite IC 310 having been classified as a radio galaxy with the jet observed at an angle > 10 degrees, it exhibits a mixture of multiwavelength properties of a radio galaxy and a blazar, possibly making it a transitional object. On the night of 12/13th of November 2012 the MAGIC telescopes observed a series of violent outbursts from the direction of IC 310 with flux-doubling time scales faster than 5 min and a peculiar spectrum spreading over 2 orders of magnitude. Such fast variability constrains the size of the emission region to be smaller than 20% of the gravitational radius of its central black hole, challenging the shock acceleration models, commonly used in explanation of gamma-ray radiation from active galaxies. Here we will show that this emission can be associated with pulsar-like particle acceleration by the electric...

Sitarek, J; Mannheim, K; Colin, P; Kadler, M; Schultz, R; Krauß, F; Ros, E; Bach, U; Wilms, J

2015-01-01T23:59:59.000Z

223

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

DOE Patents [OSTI]

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.

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

2000-01-01T23:59:59.000Z

224

GPU accelerated simulations of 3D deterministic particle transport using discrete ordinates method  

SciTech Connect (OSTI)

Graphics Processing Unit (GPU), originally developed for real-time, high-definition 3D graphics in computer games, now provides great faculty in solving scientific applications. The basis of particle transport simulation is the time-dependent, multi-group, inhomogeneous Boltzmann transport equation. The numerical solution to the Boltzmann equation involves the discrete ordinates (S{sub n}) method and the procedure of source iteration. In this paper, we present a GPU accelerated simulation of one energy group time-independent deterministic discrete ordinates particle transport in 3D Cartesian geometry (Sweep3D). The performance of the GPU simulations are reported with the simulations of vacuum boundary condition. The discussion of the relative advantages and disadvantages of the GPU implementation, the simulation on multi GPUs, the programming effort and code portability are also reported. The results show that the overall performance speedup of one NVIDIA Tesla M2050 GPU ranges from 2.56 compared with one Intel Xeon X5670 chip to 8.14 compared with one Intel Core Q6600 chip for no flux fixup. The simulation with flux fixup on one M2050 is 1.23 times faster than on one X5670.

Gong Chunye, E-mail: gongchunye@gmail.com [School of Computer Science, National University of Defense Technology, Changsha 410073 (China); Liu Jie, E-mail: liujie@nudt.edu.cn [School of Computer Science, National University of Defense Technology, Changsha 410073 (China); Chi Lihua [School of Computer Science, National University of Defense Technology, Changsha 410073 (China); Huang Haowei [Institut fuer Informatik, Technische Universitaet Muenchen, D-85748 Garching, Munich (Germany); Fang Jingyue [School of Physics and Mathematics, National University of Defense Technology, Changsha 410073 (China); Gong Zhenghu [School of Computer Science, National University of Defense Technology, Changsha 410073 (China)

2011-07-01T23:59:59.000Z

225

Alignment tolerance of accelerating structures and corrections for future linear colliders  

SciTech Connect (OSTI)

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.

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

1995-06-01T23:59:59.000Z

226

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

227

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

E-Print Network [OSTI]

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...

Bian, Nicolas H; Ratcliffe, Heather

2015-01-01T23:59:59.000Z

228

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

SciTech Connect (OSTI)

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.

Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik, E-mail: hskang@postech.ac.kr [Pohang Accelerator Laboratory, San31, Hyoja-dong, Pohang, Gyeongbuk 790-784 (Korea, Republic of)

2014-02-14T23:59:59.000Z

229

Dense Linear Algebra Solvers for Multicore with GPU Accelerators Stanimire Tomov1  

E-Print Network [OSTI]

, Hatem Ltaief1 , and Jack Dongarra1,2,3 1 Department of Electrical Engineering and Computer Science, as power consumption is typically proportional to the cube of the frequency, GPUs have a clear advantage of these fundamental libraries, and in particular, libraries in the area of dense linear algebra (DLA). Historically

Dongarra, Jack

230

Measurement of the neutron leakage from a dedicated intraoperative radiation therapy electron linear accelerator and a conventional linear accelerator for 9, 12, 15(16), and 18(20) MeV electron energies  

SciTech Connect (OSTI)

The issue of neutron leakage has recently been raised in connection with dedicated electron-only linear accelerators used for intraoperative radiation therapy (IORT). In particular, concern has been expressed about the degree of neutron production at energies of 10 MeV and higher due to the need for additional, perhaps permanent, shielding in the room in which the device is operated. In particular, three mobile linear accelerators available commercially offer electron energies at or above the neutron threshold, one at 9 MeV, one at 10 MeV, and the third at 12 MeV. To investigate this problem, neutron leakage has been measured around the head of two types of electron accelerators at a distance of 1 m from the target at azimuthal angles of 0 deg., 45 deg., 90 deg., 135 deg., and 180 deg. The first is a dedicated electron-only (nonmobile) machine with electron energies of 6 (not used here), 9, 12, 15, and 18 MeV and the second a conventional machine with electron energies of 6 (also not used here), 9, 12, 16, and 20 MeV. Measurements were made using neutron bubble detectors and track-etch detectors. For electron beams from a conventional accelerator, the neutron leakage in the forward direction in Sv/Gy is 2.1x10{sup -5} at 12 MeV, 1.3x10{sup -4} at 16 MeV, and 4.2x10{sup -4} at 20 MeV, assuming a quality factor (RBE) of 10. For azimuthal angles >0 deg., the leakage is almost angle independent [2x10{sup -6} at 12 MeV; (0.7-1.6)x10{sup -5} at 16 MeV, and (1.6-2.9)x10{sup -5} at 20 MeV]. For the electron-only machine, the neutron leakage was lower than for the conventional linac, but also independent of azimuthal angle for angles >0 deg. : ([0 deg. : 7.7x10{sup -6} at 12 MeV; 3.0x10{sup -5} at 15 MeV; 1.0x10{sup -4} at 18 MeV]; [other angles: (2.6-5.9)x10{sup -7} at 12 MeV; (1.4-2.2)x10{sup -6} at 15 MeV; (2.7-4.7)x10{sup -6} at 18 MeV]). Using the upper limit of 6x10{sup -7} Sv/Gy at 12 MeV for the IORT machine for azimuthal angles >0 deg. and assuming a workload of 200 Gy/wk and an inverse square factor of 10, the neutron dose equivalent is calculated to be 0.012 mSv/wk. For the primary beam at 12 MeV (0 deg. ), the 10x higher dose would be compensated by the attenuation of a primary beam stopper in a mobile linear accelerator. These neutron radiation levels are below regulatory values (National Council on Radiation Protection and Measurements, 'Limitation of exposure to ionizing radiation', NCRP Report No. 116, NCRP Bethesda, MD, 1993)

Jaradat, Adnan K.; Biggs, Peter J. [Department of Physics, University of Massachusetts Lowell, One University Avenue, Lowell, Massachusetts 01854 (United States); Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 (United States)

2008-05-15T23:59:59.000Z

231

Efficient and stable proton acceleration by irradiating a two-layer target with a linearly polarized laser pulse  

SciTech Connect (OSTI)

We report an efficient and stable scheme to generate {approx}200 MeV proton bunch by irradiating a two-layer targets (near-critical density layer+solid density layer with heavy ions and protons) with a linearly polarized Gaussian pulse at intensity of 6.0 Multiplication-Sign 10{sup 20} W/cm{sup 2}. Due to self-focusing of laser and directly accelerated electrons in the near-critical density layer, the proton energy is enhanced by a factor of 3 compared to single-layer solid targets. The energy spread of proton is also remarkably reduced. Such scheme is attractive for applications relevant to tumor therapy.

Wang, H. Y.; Yan, X. Q.; Chen, J. E.; He, X. T. [State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China) and Key Lab of High Energy Density Physics Simulation, CAPT, Peking University, Beijing 100871 (China); Ma, W. J.; Bin, J. H.; Schreiber, J.; Tajima, T.; Habs, D. [Fakultaet fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, Am Coulombwall 1, 85748 Garching (Germany) and Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching (Germany)

2013-01-15T23:59:59.000Z

232

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

E-Print Network [OSTI]

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 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\\"ohlich, J. Fluid Mech., 709: 445-489, 2012). Numerical tests with binary as well as multiple particle collisions are included that illustrate the accuracy of the proposed method and its superiority in terms of numerical efficiency.

Shouryya Ray; Tobias Kempe; Jochen Fröhlich

2015-02-26T23:59:59.000Z

233

Electron acceleration with improved Stochastic Differential Equation method: cutoff shape of electron distribution in test-particle limit  

E-Print Network [OSTI]

We develop a method of stochastic differential equation to simulate electron acceleration at astrophysical shocks. Our method is based on It\\^{o}'s stochastic differential equations coupled with a particle splitting, employing a skew Brownian motion where an asymmetric shock crossing probability is considered. Using this code, we perform simulations of electron acceleration at stationary plane parallel shock with various parameter sets, and studied how the cutoff shape, which is characterized by cutoff shape parameter $a$, changes with the momentum dependence of the diffusion coefficient $\\beta$. In the age-limited cases, we reproduce previous results of other authors, $a\\approx2\\beta$. In the cooling-limited cases, the analytical expectation $a\\approx\\beta+1$ is roughly reproduced although we recognize deviations to some extent. In the case of escape-limited acceleration, numerical result fits analytical stationary solution well, but deviates from the previous asymptotic analytical formula $a\\approx\\beta$.

Yamazaki, Ryo; Tsuchihashi, Yuka; Nakajima, Ryosuke; Ohira, Yutaka; Yanagita, Shohei

2015-01-01T23:59:59.000Z

234

Efficient Modeling of Plasma Wake Field Acceleration Experiments Using Particle-In-Cell Methods  

E-Print Network [OSTI]

bubble) and (c) the beam particles (plotted as colored dots:bubble) and (c) the beam particles (plotted as colored dots:

An, Weiming

2013-01-01T23:59:59.000Z

235

COLLECTIVE PHENOMENA IN ACCELERATORS  

E-Print Network [OSTI]

Proc. 1971 Particle Accelerator Conference, IEEE Trans. onConference on High-Energy Accelerators) 1971 (CERN, Geneva,and P. R. Zenkevich, Particle Accelerators b 1 (1972). M. S.

Sessler, Andrew M.

2008-01-01T23:59:59.000Z

236

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

SciTech Connect (OSTI)

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.

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

2014-03-15T23:59:59.000Z

237

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

E-Print Network [OSTI]

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

Wurtele, Jonathan

238

A Framework for a General Purpose Intelligent Control System for Particle Accelerators. Phase II Final Report  

SciTech Connect (OSTI)

Vista Control Systems, Inc. has developed a portable system for intelligent accelerator control. The design is general in scope and is thus configurable to a wide range of accelerator facilities and control problems. The control system employs a multi-layer organization in which knowledge-based decision making is used to dynamically configure lower level optimization and control algorithms.

Dr. Robert Westervelt; Dr. William Klein; Dr. Michael Kroupa; Eric Olsson; Rick Rothrock

1999-06-28T23:59:59.000Z

239

Gantry and isocenter displacements of a linear accelerator caused by an add-on micromultileaf collimator  

SciTech Connect (OSTI)

Purpose: The delivery of high quality stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) treatments to the patient requires knowledge of the position of the isocenter to submillimeter accuracy. To meet the requirements the deviation between the radiation and mechanical isocenters must be less than 1 mm. The use of add-on micromultileaf collimators ({mu}MLCs) in SRS and SRT is an additional challenge to the anticipated high-level geometric and dosimetric accuracy of the treatment. The aim of this work was to quantify the gantry excursions during rotation with and without an add-on {mu}MLC attached to the gantry head. In addition, the shift in the position of the isocenter and its correlation to the kV beam center of the cone-beam CT system was included in the study. Methods: The quantification of the gantry rotational performance was done using a pointer supported by an in-house made rigid holder attached to the gantry head of the accelerator. The pointer positions were measured using a digital theodolite. To quantify the effect of an {mu}MLC of 50 kg, the measurements were repeated with the {mu}MLC attached to the gantry head. The displacement of the isocenter due to an add-on {mu}MLC of 50 kg was also investigated. In case of the pointer measurement the {mu}MLC was simulated by weights attached to the gantry head. A method of least squares was applied to determine the position and displacement of the mechanical isocenter. Additionally, the displacement of the radiation isocenter was measured using a ball-bearing phantom and the electronic portal image device system. These measurements were based on 8 MV photon beams irradiated onto the ball from the four cardinal angles and two opposed collimator angles. The measurements and analysis of the data were carried out automatically using software delivered by the manufacturer. Results: The displacement of the mechanical isocenter caused by a 50 kg heavy {mu}MLC was found to be (-0.01 {+-} 0.05, -0.10 {+-} 0.03, -0.26 {+-} 0.05) mm in lateral, longitudinal, and vertical direction, respectively. Similarly, the displacement of the radiation isocenter was found to be (0.00 {+-} 0.03, -0.08 {+-} 0.06, -0.32 {+-} 0.02) mm. Good agreement was found between the displacement of the two isocenters. A displacement of the kV cone-beam CT beam center due to the attached weight of 50 kg could not be detected. Conclusions: General characteristics of the gantry arm excursions and displacements caused by an add-on {mu}MLC have been reported. A 50 kg heavy add-on {mu}MLC results in a isocenter displacement downward of 0.26-0.32 mm. The authors recommend that the beam center of the kV cone-beam CT image system should be matched to the isocenter related to the weight of the {mu}MLC. Consequently, the imperfections in isocenter localizations are transferred to the conventional radiotherapy where the clinical consequences of uncertainties in the submillimeter regime are negligible.

Riis, Hans L.; Zimmermann, Sune J.; Hjelm-Hansen, Mogens [Radiofysisk Laboratorium, Odense University Hospital, Sdr. Boulevard 29, DK-5000 Odense C (Denmark)

2013-03-15T23:59:59.000Z

240

Time dependence of particle creation from accelerating mirrors Michael R. R. Good*  

E-Print Network [OSTI]

time resolution of the particle production process can be obtained. DOI: 10.1103/PhysRevD.88 that has been largely unexplored is the study of the time dependence of the particle production process dependence of creation. One way to explore the time dependence of particle production is through the use

Anderson, Paul R.

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While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Three-dimensional, Time-Resolved, Intrafraction Motion Monitoring Throughout Stereotactic Liver Radiation Therapy on a Conventional Linear Accelerator  

SciTech Connect (OSTI)

Purpose: To investigate the time-resolved 3-dimensional (3D) internal motion throughout stereotactic body radiation therapy (SBRT) of tumors in the liver using standard x-ray imagers of a conventional linear accelerator. Methods and Materials: Ten patients with implanted gold markers received 11 treatment courses of 3-fraction SBRT in a stereotactic body-frame on a conventional linear accelerator. Two pretreatment and 1 posttreatment cone-beam computed tomography (CBCT) scans were acquired during each fraction. The CBCT projection images were used to estimate the internal 3D marker motion during CBCT acquisition with 11-Hz resolution by a monoscopic probability-based method. Throughout the treatment delivery by conformal or volumetric modulated arc fields, simultaneous MV portal imaging (8 Hz) and orthogonal kV imaging (5 Hz) were applied to determine the 3D marker motion using either MV/kV triangulation or the monoscopic method when marker segmentation was unachievable in either MV or kV images. The accuracy of monoscopic motion estimation was quantified by also applying monoscopic estimation as a test for all treatments during which MV/kV triangulation was possible. Results: Root-mean-square deviations between monoscopic estimations and triangulations were less than 1.0 mm. The mean 3D intrafraction and intrafield motion ranges during liver SBRT were 17.6 mm (range, 5.6-39.5 mm) and 11.3 mm (2.1-35.5mm), respectively. The risk of large intrafraction baseline shifts correlated with intrafield respiratory motion range. The mean 3D intrafractional marker displacement relative to the first CBCT was 3.4 mm (range, 0.7-14.5 mm). The 3D displacements exceeded 8.8 mm 10% of the time. Conclusions: Highly detailed time-resolved internal 3D motion was determined throughout liver SBRT using standard imaging equipment. Considerable intrafraction motion was observed. The demonstrated methods provide a widely available approach for motion monitoring that, combined with motion-adaptive treatment techniques, has the potential to improve the accuracy of radiation therapy for moving targets.

Worm, Esben S., E-mail: esbeworm@rm.dk [Department of Oncology, Aarhus University Hospital, Aarhus (Denmark); Institute of Clinical Medicine, Aarhus University (Denmark); Hřyer, Morten; Fledelius, Walter [Department of Oncology, Aarhus University Hospital, Aarhus (Denmark)] [Department of Oncology, Aarhus University Hospital, Aarhus (Denmark); Poulsen, Per R. [Department of Oncology, Aarhus University Hospital, Aarhus (Denmark) [Department of Oncology, Aarhus University Hospital, Aarhus (Denmark); Institute of Clinical Medicine, Aarhus University (Denmark)

2013-05-01T23:59:59.000Z

242

Environmental Assessment for US Department of Energy support of an Iowa State University Linear Accelerator Facility at Ames, Iowa  

SciTech Connect (OSTI)

The proposed Department of Energy (DOE) action is financial and technical support of construction and initial operation of an agricultural commodity irradiator (principally for meat), employing a dual mode electron beam generator capable of producing x-rays, at the Iowa State University Linear Accelerator located at Ames, Iowa. The planned pilot commercial-scale facility would be used for the following activities: conducting irradiation research on agricultural commodities, principally meats; in the future, after the pilot phase, as schedules permit, possibly conducting research on other, non-edible materials; evaluating effects of irradiation on nutritional and sensory quality of agricultural products; demonstrating the efficiency of the process to control or eliminate pathogens, and/or to prolong the commodities' post-harvest shelf-life via control or elimination of bacteria, fungi, and/or insects; providing information to the public on the benefits, safety and risks of irradiated agricultural commodities; determining consumer acceptability of the irradiated products; providing data for use by regulatory agencies in developing protocols for various treatments of Iowa agricultural commodities; and training operators, maintenance and quality control technicians, scientists, engineers, and staff of regulatory agencies in agricultural commodity irradiation technology. 14 refs., 5 figs.

Not Available

1990-05-01T23:59:59.000Z

243

Efficient Modeling of Plasma Wake Field Acceleration Experiments Using Particle-In-Cell Methods  

E-Print Network [OSTI]

diagnostics . . . . .The plasma particle diagnostic andthe beam and plasma initialization and diagnostic routines.beam and plasma initialization, and diagnostics. In the

An, Weiming

2013-01-01T23:59:59.000Z

244

Experience of micromultileaf collimator linear accelerator based single fraction stereotactic radiosurgery: Tumor dose inhomogeneity, conformity, and dose fall off  

SciTech Connect (OSTI)

Purpose: Sharp dose fall off outside a tumor is essential for high dose single fraction stereotactic radiosurgery (SRS) plans. This study explores the relationship among tumor dose inhomogeneity, conformity, and dose fall off in normal tissues for micromultileaf collimator (mMLC) linear accelerator (LINAC) based cranial SRS plans. Methods: Between January 2007 and July 2009, 65 patients with single cranial lesions were treated with LINAC-based SRS. Among them, tumors had maximum diameters {<=}20 mm: 31; between 20 and 30 mm: 21; and >30 mm: 13. All patients were treated with 6 MV photons on a Trilogy linear accelerator (Varian Medical Systems, Palo Alto, CA) with a tertiary m3 high-resolution mMLC (Brainlab, Feldkirchen, Germany), using either noncoplanar conformal fixed fields or dynamic conformal arcs. The authors also created retrospective study plans with identical beam arrangement as the treated plan but with different tumor dose inhomogeneity by varying the beam margins around the planning target volume (PTV). All retrospective study plans were normalized so that the minimum PTV dose was the prescription dose (PD). Isocenter dose, mean PTV dose, RTOG conformity index (CI), RTOG homogeneity index (HI), dose gradient index R{sub 50}-R{sub 100} (defined as the difference between equivalent sphere radius of 50% isodose volume and prescription isodose volume), and normal tissue volume (as a ratio to PTV volume) receiving 50% prescription dose (NTV{sub 50}) were calculated. Results: HI was inversely related to the beam margins around the PTV. CI had a ''V'' shaped relationship with HI, reaching a minimum when HI was approximately 1.3. Isocenter dose and mean PTV dose (as percentage of PD) increased linearly with HI. R{sub 50}-R{sub 100} and NTV{sub 50} initially declined with HI and then reached a plateau when HI was approximately 1.3. These trends also held when tumors were grouped according to their maximum diameters. The smallest tumor group (maximum diameters {<=}20 mm) had the most HI dependence for dose fall off. For treated plans, CI averaged 2.55{+-}0.79 with HI 1.23{+-}0.06; the average R{sub 50}-R{sub 100} was 0.41{+-}0.08, 0.55{+-}0.10, and 0.65{+-}0.09 cm, respectively, for tumors {<=}20 mm, between 20 and 30 mm, and >30 mm. Conclusions: Tumor dose inhomogeneity can be used as an important and convenient parameter to evaluate mMLC LINAC-based SRS plans. Sharp dose fall off in the normal tissue is achieved with sufficiently high tumor dose inhomogeneity. By adjusting beam margins, a homogeneity index of approximately 1.3 would provide best conformity for the authors' SRS system.

Hong, Linda X.; Garg, Madhur; Lasala, Patrick; Kim, Mimi; Mah, Dennis; Chen, Chin-Cheng; Yaparpalvi, Ravindra; Mynampati, Dinesh; Kuo, Hsiang-Chi; Guha, Chandan; Kalnicki, Shalom [Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Neurosurgery, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Epidemiology and Population Health, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States)

2011-03-15T23:59:59.000Z

245

Multiorbit induction accelerators  

SciTech Connect (OSTI)

Large numbers of particles accelerated per cycle are made possible by accelerating simultaneously in several equilibrium orbits in a single betatron structure. (AIP)

Zvontsov, A.A.; Kas'yanov, V.A.; Chakhlov, V.L.

1985-09-01T23:59:59.000Z

246

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

SciTech Connect (OSTI)

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.

Kontorovich, V. M., E-mail: vkont1001@yahoo.com; Flanchik, A. B. [National Academy of Sciences of Ukraine, Institute of Radio Astronomy (Ukraine)] [National Academy of Sciences of Ukraine, Institute of Radio Astronomy (Ukraine)

2013-01-15T23:59:59.000Z

247

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

SciTech Connect (OSTI)

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.

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)

2013-08-15T23:59:59.000Z

248

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

SciTech Connect (OSTI)

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)

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

1982-02-01T23:59:59.000Z

249

Induction of linear tracks of DNA double-strand breaks by -particle irradiation of  

E-Print Network [OSTI]

eukaryotic cells by exposing the cells to particles from a small Americium source (Box 1). Each particle) EQUIPMENT Americium (Am-241) source (SupplementaryMethods and SupplementaryFigs.1­3 online) Polyester film

Cai, Long

250

Design Considerations for Plasma Accelerators Driven by Lasers or Particle Beams  

E-Print Network [OSTI]

al. , Phys. Rev. ST Accel. Beams, submitted, (2010). 15. A.D . Kimura, Phys. Rev. ST Accel. Beams 13, 24. C . Jing, A .Driven by Lasers or Particle Beams C . B . Schroeder, E .

Schroeder, C. B.

2011-01-01T23:59:59.000Z

251

Particle acceleration close to the supermassive black hole horizon: the case of M87  

E-Print Network [OSTI]

The radio galaxy M87 has recently been found to be a rapidly variable TeV emitting source. We analyze the implications of the observed TeV characteristics and show that it proves challenging to account for them within conventional acceleration and emission models. We discuss a new pulsar-type scenario for the origin of variable, very high energy (VHE) emission close to the central supermassive black hole and show that magneto-centrifugally accelerated electrons could efficiently Compton upscatter sub-mm ADAF disk photons to the TeV regime, leading to VHE characteristics close to the observed ones. This suggests, conversely, that VHE observations of highly under-luminous AGNs could provide an important diagnostic tool for probing the conditions prevalent in the inner accretion disk of these sources.

F. M. Rieger; F. A. Aharonian

2008-05-27T23:59:59.000Z

252

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]

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.

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

2012-01-01T23:59:59.000Z

253

High rate resistive plate chambers: An inexpensive, fast, large area detector of energetic charged particles for accelerator and non-accelerator applications  

SciTech Connect (OSTI)

Resistive Plate Chambers, or RPCs, have been used until recently as large detectors of cosmic ray muons. They are now finding use as fast large-area trigger and muon detection systems for different high energy physics detectors such the L3 Detector at LEP and future detectors to be built at the Superconducting Super Collider (SSC) and at the Large Hadron Collider (LHC) at CERN. RPC systems at these accelerators must operate with high efficiency, providing nanosecond timing resolution in particle fluences up to a few tens of kHz/cm{sup 2} -- with thousands of square meters of active area. RPCs are simple and cheap to construct. The authors report here recent work on RPCs using new materials that exhibit a combination of desirable RPC features such as low bulk resistivity, high dielectric strength, low mass, and low cost. These new materials were originally developed for use in electronics assembly areas and other applications, where static electric charge buildup can damage sensitive electrical systems.

Wuest, C.R.; Ables, E.; Bionta, R.M.; Clamp, O.; Haro, M.; Mauger, G.J.; Miller, K.; Olson, H.; Ramsey, P.

1993-05-01T23:59:59.000Z

254

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

E-Print Network [OSTI]

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.

Zach Medin; Dong Lai

2008-01-18T23:59:59.000Z

255

Kinetic Theories of Geodesic Acoustic Modes: Radial Structure, Linear Excitation by Energetic Particles and Nonlinear Saturation  

E-Print Network [OSTI]

Kinetic Theories of Geodesic Acoustic Modes: Radial Structure, Linear Excitation by Energetic, Vol.13, No.3, Jun 2011 Kinetic Theories of Geodesic Acoustic Modes: Radial Structure, Linear, Univ. of California, Irvine CA 92697-4575, USA Abstract Geodesic acoustic modes (GAMs) are oscillating

Zonca, Fulvio

256

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

E-Print Network [OSTI]

, Finland Department of Physics, University of Helsinki, Finland Abstract. We have developed a simulation- ered the primary source of large solar energetic parti- cle (SEP) intensities. Injected particles repeatedly cross the shock front, scattering from the plasma waves, and gain energy on each crossing

Sanahuja, Blai

257

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

DOE Patents [OSTI]

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.

Maschke, A.W.

1980-09-23T23:59:59.000Z

258

Trace of phase-space noncommutativity in the response of a free particle to linearized gravitational waves  

E-Print Network [OSTI]

Interaction of linearized gravitational waves with a otherwise free particle has been studied quantum mechanically in a noncommutative phase-space to examine whether the particle's response to the gravitational wave gets modified due to spatial and/or momentum noncommutativity. The result shows that momentum noncommutativity introduces a oscillatory noise with a specific frequency determined by the fundamental momentum scale and particle mass. Because of the global nature of the phase-space noncommutativity such noise will have similar characteristics for all detector sites and thus will stand out in a data cross-correlation procedure. If detected, this noise will provide evidence of momentum noncommutativity and also an estimation of the relevant noncommutative parameter.

Sunandan Gangopadhyay; Anirban Saha; Swarup Saha

2014-01-27T23:59:59.000Z

259

Maximal acceleration or maximal accelerations?  

E-Print Network [OSTI]

We review the arguments supporting the existence of a maximal acceleration for a massive particle and show that different values of this upper limit can be predicted in different physical situations.

A. Feoli

2002-10-12T23:59:59.000Z

260

Detailed dynamics of electron beams self-trapped and accelerated in a self-modulated laser wakefield  

E-Print Network [OSTI]

. These features are explained by analysis and test particle simulations of electron dynamics during acceleration wave,1 such as the plasma wakefield accel- erator, the plasma beat-wave accelerator, the Laser Wake the linear dephasing limit, and explained it, using Particle-In-Cell PIC simulations, as a result

Umstadter, Donald

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


261

Interactive visual intervention planning in particle accelerator environments with ionizing radiation  

E-Print Network [OSTI]

Radiation is omnipresent. It has many interesting applications: in medicine, where it allows curing and diagnosing patients; in communication, where modern communication systems make use of electromagnetic radiation; and in science, where it is used to discover the structure of materials; to name a few. Physically, radiation is a process in which particles or waves travel through any kind of material, usually air. Radiation can be very energetic, in which case it can break the atoms of ordinary matter (ionization). If this is the case, radiation is called ionizing. It is known that ionizing radiation can be far more harmful to living beings than non-ionizing radiation. In this dissertation, we are concerned with ionizing radiation. Naturally occurring ionizing radiation in the form of radioactivity is a most natural phenomenon. Almost everything is radioactive: there is radiation emerging from the soil, it is in the air, and the whole planet is constantly undergoing streams of energetic cosmic radiation. Sinc...

Fabry, Thomas

262

Electron Beam Charge Diagnostics for Laser Plasma Accelerators  

E-Print Network [OSTI]

the 1989 Particle Accelerator Conference (IEEE, Piscataway,the 1993 Particle Accelerator Conference (IEEE, Piscataway,Diagnostics for Laser Plasma Accelerators K. Nakamura, 1 A.

Nakamura, Kei

2012-01-01T23:59:59.000Z

263

Charge Diagnostics for Laser Plasma Accelerators  

E-Print Network [OSTI]

the 1989 Particle Accelerator Conference, IEEE, Piscataway,Diagnostics for Laser Plasma Accelerators K . Nakamura, A .ALS) synchrotron booster accelerator. The sensitivity of the

Nakamura, K.

2011-01-01T23:59:59.000Z

264

Blind Analysis in Particle Physics Aaron Roodman  

E-Print Network [OSTI]

Blind Analysis in Particle Physics Aaron Roodman Stanford Linear Accelerator Center, Stanford, CA 94025, USA A review of the blind analysis technique, as used in particle physics measurements, is presented. The history of blind analyses in physics is briefly discussed. Next the dangers of experimenter

Browder, Tom

265

Dense Linear Algebra Solvers for Multicore with GPU Accelerators Stanimire Tomov, Rajib Nath, Hatem Ltaief, and Jack Dongarra  

E-Print Network [OSTI]

Ltaief, and Jack Dongarra Department of Electrical Engineering and Computer Science, University, as power consumption is typically proportional to the cube of the frequency, GPUs have a clear advantage of these fundamental libraries, and in particular, libraries in the area of dense linear algebra (DLA). Historically

Dongarra, Jack

266

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region service area. TheEPSCI Home ItDark Energy SurveyResourcesMay

267

ACCELERATORS FOR THE 21ST CENTURY E. Keil, CERN, Geneva, Switzerland  

E-Print Network [OSTI]

ACCELERATORS FOR THE 21ST CENTURY E. Keil, CERN, Geneva, Switzerland Abstract Accelerators- collider, using the example of CLIC. The main e+ e- beams are generated by a sequence of linear accel" parameters, those in the lower part are related to the beam-beam collisions and particle physics. We in

Keil, Eberhard

268

Derivation of Hamiltonians for accelerators  

SciTech Connect (OSTI)

In this report various forms of the Hamiltonian for particle motion in an accelerator will be derived. Except where noted, the treatment will apply generally to linear and circular accelerators, storage rings, and beamlines. The generic term accelerator will be used to refer to any of these devices. The author will use the usual accelerator coordinate system, which will be introduced first, along with a list of handy formulas. He then starts from the general Hamiltonian for a particle in an electromagnetic field, using the accelerator coordinate system, with time t as independent variable. He switches to a form more convenient for most purposes using the distance s along the reference orbit as independent variable. In section 2, formulas will be derived for the vector potentials that describe the various lattice components. In sections 3, 4, and 5, special forms of the Hamiltonian will be derived for transverse horizontal and vertical motion, for longitudinal motion, and for synchrobetatron coupling of horizontal and longitudinal motions. Hamiltonians will be expanded to fourth order in the variables.

Symon, K.R.

1997-09-12T23:59:59.000Z

269

Effects of Hyperbolic Rotation in Minkowski Space on the Modeling of Plasma Accelerators in a Lorentz Boosted Frame  

E-Print Network [OSTI]

al. , in Proc. Particle Accelerator Conference ( Vancouver,al. , in Proc. Particle Accelerator Conference (Vancouver,al. , in Proc. Particle Accelerator Con- ference (Vancouver,

Vay, J.-L.

2010-01-01T23:59:59.000Z

270

LASER-PLASMA-ACCELERATOR-BASED GAMMA GAMMA COLLIDERS  

E-Print Network [OSTI]

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

Schroeder, C. B.

2010-01-01T23:59:59.000Z

271

Accelerator-Based Irradiation Creep of Pyrolytic Carbon Used in TRISO Fuel Particles for the (VHTR) Very Hight Temperature Reactors  

SciTech Connect (OSTI)

Pyrolytic carbon (PyC) is one of the important structural materials in the TRISO fuel particles which will be used in the next generation of gas-cooled very-high-temperature reactors (VHTR). When the TRISO particles are under irradiation at high temperatures, creep of the PyC layers may cause radial cracking leading to catastrophic particle failure. Therefore, a fundamental understanding of the creep behavior of PyC during irradiation is required to predict the overall fuel performance.

Lumin Wang; Gary Was

2010-07-30T23:59:59.000Z

272

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

SciTech Connect (OSTI)

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.

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

1986-12-01T23:59:59.000Z

273

Enabling pulse compression and proton acceleration in a modular ICF driver for nuclear and particle physics applications  

E-Print Network [OSTI]

The existence of efficient ion acceleration regimes in collective laser-plasma interactions opens up the possibility to develop high-energy physics facilities in conjunction with projects for inertial confinement nuclear fusion (ICF) and neutron spallation sources. In this paper, we show that the pulse compression requests to make operative these acceleration mechanisms do not fall in contradiction with current technologies for high repetition rate ICF drivers. In particular, we discuss explicitly a solution that exploits optical parametric chirped pulse amplification and the intrinsic modularity of the lasers aimed at ICF.

F. Terranova; S. V. Bulanov; J. L. Collier; H. Kiriyama; F. Pegoraro

2005-12-07T23:59:59.000Z

274

Measurement of the B0 ---> Psi (2S) Lambda0 Branching Fraction on BaBar at the Stanford Linear Accelerator Center (Abstract Only)  

SciTech Connect (OSTI)

The decays of B{sup 0} mesons to hadronic final states remains a rich area of physics on BaBar. Not only do the c{bar c}-K final states (e.g. B{sup 0} {yields} {psi}(2S)K{sup 0}) allow for the measurement of CP Violation, but the branching fractions provide a sensitive test of the theoretical methods used to account for low energy non-perturbative QCD effects. They present the measurement of the branching fraction for the decay B{sup 0} {yields} {psi}(2S)K{sub s}. The data set consists of 88.8 {+-} 1.0 x 10{sup 6} B{bar b} pairs collected on the e{sup +}e{sup -} {yields} {Upsilon}(4S) resonance on BaBar/PEP-II at the Stanford Linear Accelerator Center (SLAC). This analysis features a modification of present cuts, with respect to those published so far on BaBar, on the K{sub S} {yields} {pi}{sup +}{pi}{sup -} and {psi}(2S) {yields} J/{psi}{pi}{sup +}{pi}{sup -} which aim at reducing the background while keeping the signal intact. Various data selection criteria are studied for the lepton modes (e{sup +}e{sup -} and {mu}{sup +}{mu}{sup -}) of the J/{psi} and {psi}(2S) to improve signal purity as well as study the stability of the resultant branching fractions.

Olivas, Alexander Raymond, Jr.; /Colorado U.

2005-11-16T23:59:59.000Z

275

Staging laser plasma accelerators for increased beam energy  

E-Print Network [OSTI]

Staging Laser Plasma Accelerators for Increased Beam EnergyStaging laser plasma accelerators is an efficient way ofcompact laser-plasma accelerators to generate particle

Panasenko, Dmitriy

2010-01-01T23:59:59.000Z

276

Accelerators: powering cutting-edge research  

E-Print Network [OSTI]

Accelerators: powering cutting-edge research #12;What is a particle accelerator? Booster ourselves. Particle accelerators are our attempt to turn back the clock and see into the early stages of the Universe. They accelerate everyday charged particles (electrons or protons) to close to the speed of light

Crowther, Paul

277

Accelerated Quantum Dynamics  

E-Print Network [OSTI]

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.

Lynch, Morgan H

2015-01-01T23:59:59.000Z

278

Proposal for the Award of Two Contracts for the Technical Services for Work on Components of CERN Particle Accelerators and High Energy Physics Experiments  

E-Print Network [OSTI]

This document concerns the award of two contracts for the technical services for work on components of CERN particle accelerators and high energy physics experiments. Following a market survey carried out among 73 firms in fourteen Member States, a call for tenders (IT-3156/SPL) was sent on 4 November 2002 to three consortia in four Member States. By the closing date, CERN had received tenders from the three consortia. The Finance Committee is invited to agree to the negotiation of two contracts with: 1) the consortium SERCO FACILITIES MANAGEMENT (NL) - GERARD PERRIER INDUSTRIE (FR) - INEO ALPES (FR), the lowest bidder, for approximately 55% of the technical services for work on components of CERN particle accelerators and high energy physics experiments, for an initial period of five years and for a total amount not exceeding 37 435 270 euros (54 902 500 Swiss francs), subject to revision for inflation from 1 January 2005. The contract will include options for two one-year extensions beyond the initial five-...

2003-01-01T23:59:59.000Z

279

Energy Doubling of 42 GeV Electrons in a Meter-scale Plasma Wakefield Accelerator  

SciTech Connect (OSTI)

The energy frontier of particle physics is several trillion electron volts, but colliders capable of reaching this regime (such as the Large Hadron Collider and the International Linear Collider) are costly and time-consuming to build; it is therefore important to explore new methods of accelerating particles to high energies. Plasma-based accelerators are particularly attractive because they are capable of producing accelerating fields that are orders of magnitude larger than those used in conventional colliders. In these accelerators, a drive beam (either laser or particle) produces a plasma wave (wakefield) that accelerates charged particles. The ultimate utility of plasma accelerators will depend on sustaining ultrahigh accelerating fields over a substantial length to achieve a significant energy gain. Here we show that an energy gain of more than 42 GeV is achieved in a plasma wakefield accelerator of 85 cm length, driven by a 42 GeV electron beam at the Stanford Linear Accelerator Center (SLAC). The results are in excellent agreement with the predictions of three-dimensional particle-in-cell simulations. Most of the beam electrons lose energy to the plasma wave, but some electrons in the back of the same beam pulse are accelerated with a field of {approx} 52GV m{sup -1}. This effectively doubles their energy, producing the energy gain of the 3-km-long SLAC accelerator in less than a meter for a small fraction of the electrons in the injected bunch. This is an important step towards demonstrating the viability of plasma accelerators for high-energy physics applications.

Blumenfeld, Ian; Clayton, Christopher E.; Decker, Franz-Josef; Hogan, Mark J.; Huang, Chengkun; Ischebeck, Rasmus; Iverson, Richard; Joshi, Chandrashekhar; Katsouleas,; Kirby, Neil; Lu, Wei; Marsh, Kenneth A.; Mori, Warren B.; Muggli, Patric; Oz, Erdem; Siemann, Robert H.; Walz, Dieter; Zhou, Miaomiao; /SLAC /UCLA /Southern California U.

2007-03-14T23:59:59.000Z

280

Particle Physics Booklet 2008  

E-Print Network [OSTI]

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

et al., C. Amsler

2008-01-01T23:59:59.000Z

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


281

Future Accelerators, Muon Colliders, and Neutrino Factories  

SciTech Connect (OSTI)

Particle physics is driven by five great topics. Neutrino oscillations and masses are now at the fore. The standard model with extensions to supersymmetry and a Higgs to generate mass explains much of the field. The origins of CP violation are not understood. The possibility of extra dimensions has raised tantalizing new questions. A fifth topic lurking in the background is the possibility of something totally different. Many of the questions raised by these topics require powerful new accelerators. It is not an overstatement to say that for some of the issues, the accelerator is almost the experiment. Indeed some of the questions require machines beyond our present capability. As this volume attests, there are parts of the particle physics program that have been significantly advanced without the use of accelerators such as the subject of neutrino oscillations and many aspects of the particle-cosmology interface. At this stage in the development of physics, both approaches are needed and important. This chapter first reviews the status of the great accelerator facilities now in operation or coming on within the decade. Next, midrange possibilities are discussed including linear colliders with the adjunct possibility of gamma-gamma colliders, muon colliders, with precursor neutrino factories, and very large hadron colliders. Finally visionary possibilities are considered including plasma and laser accelerators.

Richard A Carrigan, Jr.

2001-12-19T23:59:59.000Z

282

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]

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.

V. Socoliuc; L. B. Popescu

2014-10-09T23:59:59.000Z

283

Accelerators and the Accelerator Community  

E-Print Network [OSTI]

of electrostatic accelerators, while Ernest O. Lawrence (CBP 820 LBNL TBA ACCELERATORS ANDTHE ACCELERATOR COMMUNITY 1 ANDREW SESSLER Lawrence Berkeley

Malamud, Ernest

2009-01-01T23:59:59.000Z

284

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]

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.

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

1998-10-13T23:59:59.000Z

285

Klystron switching power supplies for the Internation Linear Collider  

SciTech Connect (OSTI)

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.

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

2009-12-01T23:59:59.000Z

286

Thomas Jefferson National Accelerator Facility  

SciTech Connect (OSTI)

The Thomas Jefferson National Accelerator Facility (Jefferson Lab) in Newport News, Virginia, USA, is one of ten national laboratories under the aegis of the Office of Science of the U.S. Department of Energy (DOE). It is managed and operated by Jefferson Science Associates, LLC. The primary facility at Jefferson Lab is the Continuous Electron Beam Accelerator Facility (CEBAF) as shown in an aerial photograph in Figure 1. Jefferson Lab was created in 1984 as CEBAF and started operations for physics in 1995. The accelerator uses superconducting radio-frequency (srf) techniques to generate high-quality beams of electrons with high-intensity, well-controlled polarization. The technology has enabled ancillary facilities to be created. The CEBAF facility is used by an international user community of more than 1200 physicists for a program of exploration and study of nuclear, hadronic matter, the strong interaction and quantum chromodynamics. Additionally, the exceptional quality of the beams facilitates studies of the fundamental symmetries of nature, which complement those of atomic physics on the one hand and of high-energy particle physics on the other. The facility is in the midst of a project to double the energy of the facility and to enhance and expand its experimental facilities. Studies are also pursued with a Free-Electron Laser produced by an energy-recovering linear accelerator.

Joseph Grames, Douglas Higinbotham, Hugh Montgomery

2010-09-01T23:59:59.000Z

287

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.

288

Accelerator on a Chip  

ScienceCinema (OSTI)

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)

England, Joel

2014-07-16T23:59:59.000Z

289

Accelerator on a Chip  

SciTech Connect (OSTI)

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)

England, Joel

2014-06-30T23:59:59.000Z

290

E-Print Network 3.0 - accelerator poverkhnostnaya obrabotka Sample...  

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

Stanford Linear Accelerator Center Collection: Physics 37 Demonstrations: bike wheel, rotating stool Summary: 's important: angular acceleration angular velocity and...

291

Breakthrough: Fermilab Accelerator Technology  

SciTech Connect (OSTI)

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.

None

2012-04-23T23:59:59.000Z

292

Breakthrough: Fermilab Accelerator Technology  

ScienceCinema (OSTI)

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.

None

2014-08-12T23:59:59.000Z

293

Experimental Particle Physics  

SciTech Connect (OSTI)

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.

Rosenfeld, Carl [Univ of South Carolina] (ORCID:0000000338571223); Mishra, Sanjib R. [Univ of South Carolina; Petti, Roberto [Univ of South Carolina; Purohit, Milind V. [Univ of South Carolina

2014-08-31T23:59:59.000Z

294

Future Accelerator Challenges in Support of High-Energy Physics  

SciTech Connect (OSTI)

Historically, progress in high-energy physics has largely been determined by development of more capable particle accelerators. This trend continues today with the imminent commissioning of the Large Hadron Collider at CERN, and the worldwide development effort toward the International Linear Collider. Looking ahead, there are two scientific areas ripe for further exploration--the energy frontier and the precision frontier. To explore the energy frontier, two approaches toward multi-TeV beams are being studied, an electron-positron linear collider based on a novel two-beam powering system (CLIC), and a Muon Collider. Work on the precision frontier involves accelerators with very high intensity, including a Super-BFactory and a muon-based Neutrino Factory. Without question, one of the most promising approaches is the development of muon-beam accelerators. Such machines have very high scientific potential, and would substantially advance the state-of-the-art in accelerator design. The challenges of the new generation of accelerators, and how these can be accommodated in the accelerator design, are described. To reap their scientific benefits, all of these frontier accelerators will require sophisticated instrumentation to characterize the beam and control it with unprecedented precision.

Zisman, Michael S.; Zisman, M.S.

2008-05-03T23:59:59.000Z

295

E-Print Network 3.0 - accelerator electron radiotherapy Sample...  

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

Continuous Electron Beam Accelerator Facility, Newport News, Virginia (the Big... & Phenomenology Particle Astrophysics & Cosmology Accelerator Physics Health Physics...

296

E-Print Network 3.0 - accelerator facility jefferson Sample Search...  

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

Continuous Electron Beam Accelerator Facility, Newport News, Virginia (the Big... & Phenomenology Particle Astrophysics & Cosmology Accelerator Physics Health Physics...

297

Some remarks on the quasilinear treatment of the stochastic acceleration problem  

E-Print Network [OSTI]

-standard ``diffusive'' behaviors i.e., such that the mean square displacement of a test particle does not grow linearly with zero mean and with the following second-order correlation: C x,t E x x ,t t E x ,t . 2 One also assumes of the stochastic acceleration problem, the meaning of the theory. Indeed, in recent publications,3

Van Den Eijnden, Eric

298

Primer on Detectors and Electronics for Particle Physics Experiments  

E-Print Network [OSTI]

1 Primer on Detectors and Electronics for Particle Physics Experiments Alexander A. Grillo Santa, cyclotrons, synchrotrons, and linear accelerators. The projectiles of choice were electrons and protons of detectors used in scattering experiments and the electronics required to make them work. The different

California at Santa Cruz, University of

299

Broadband Single-Shot Electron Spectrometer for GeV-Class Laser Plasma Based Accelerators  

E-Print Network [OSTI]

of the 2007 Particle Accelerator Conference, p. 2978,Class Laser Plasma Based Accelerators K. Nakamura, ? W. Wan,Laser-plasma-based accelerators can provide electrons over a

Nakamura, K.

2008-01-01T23:59:59.000Z

300

The role of plasma in advanced accelerators* Jonathan S. Wurtele+  

E-Print Network [OSTI]

concentrated on using plasma to accelerate charged particles, photon accel- eration is another area of active generation of particle accelerators. The develop- ment and status of advanced accelerator concepts, plasma beam, and is known as the particle beam wake field accelerator.6~67 While most studies have

Wurtele, Jonathan

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


301

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)

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.

Constantin, Dragos E.; Fahrig, Rebecca; Keall, Paul J. [Department of Radiology, Stanford University, Stanford, California 94305 and Division of Radiation Physics, Department of Radiation Oncology, Stanford University, Stanford California 94305 (United States); Department of Radiology, Stanford University, Stanford, California 94305 (United States); Division of Radiation Physics, Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States)

2011-07-15T23:59:59.000Z

302

E-Print Network 3.0 - accelerated l5-s1 segment Sample Search...  

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

Compensation in Laser Particle Accelerators L.C. Steinhauer and W.D. Kimura STI... Optronics, 2755 Northup Way, Bellevue, WA 98004-1495 Abstract. Laser particle acceleration...

303

Vacuum electron acceleration by using two variable frequency laser pulses  

SciTech Connect (OSTI)

A method is proposed for producing a relativistic electron bunch in vacuum via direct acceleration by using two frequency-chirped laser pulses. We consider the linearly polarized frequency-chiped Hermit-Gaussian 0, 0 mode lasers with linear chirp in which the local frequency varies linearly in time and space. Electron motion is investigated through a numerical simulation using a three-dimensional particle trajectory code in which the relativistic Newton's equations of motion with corresponding Lorentz force are solved. Two oblique laser pulses with proper chirp parameters and propagation angles are used for the electron acceleration along the z-axis. In this way, an electron initially at rest located at the origin could achieve high energy, ?=319 with the scattering angle of 1.02{sup ?} with respect to the z-axis. Moreover, the acceleration of an electron in different initial positions on each coordinate axis is investigated. It was found that this mechanism has the capability of producing high energy electron microbunches with low scattering angles. The energy gain of an electron initially located at some regions on each axis could be greatly enhanced compared to the single pulse acceleration. Furthermore, the scattering angle will be lowered compared to the acceleration by using laser pulses propagating along the z-axis.

Saberi, H.; Maraghechi, B. [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)] [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)

2013-12-15T23:59:59.000Z

304

Uncatalyzed assembly of spherical particles from SV40 VP1 pentamers and linear dsDNA incorporates both low and high cooperativity elements  

SciTech Connect (OSTI)

The capsid of SV40 virion is comprised of 72 pentamers of the major capsid protein, VP1. We examined the synergism between pentamer-pentamer interaction and pentamer-DNA interaction using a minimal system of purified VP1 and a linear dsDNA 600-mer, comparing electrophoresis with electron microscopy and size exclusion chromatography. At low VP1/DNA ratios, large tubes were observed that apparently did not survive native agarose gel electrophoresis. As the VP1 concentration increased, electrophoretic migration was slower and tubes were replaced by 200 A diameter particles and excess free pentamer. At high VP1/DNA ratios, a progressively larger fraction of particles was similar to 450 A diameter virions. VP1 association with DNA is very strong compared to the concentrations in these experiments yet, paradoxically, stable complexes appear only at high ratios of VP1 to DNA. These data suggest a DNA saturation-dependent nucleation event based on non-specific pentamer-DNA interaction that controls assembly and the ultimate capsid geometry.

Mukherjee, Santanu [Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104 (United States); Kler, Stanislav; Oppenheim, Ariella [Department of Hematology, Hebrew University-Hadassah Medical School, 91120 Jerusalem (Israel); Zlotnick, Adam, E-mail: azlotnic@indiana.ed [Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104 (United States); Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47401 (United States)

2010-02-05T23:59:59.000Z

305

PULSED-FOCUSING RECIRCULATING LINACS FOR MUON ACCELERATION  

SciTech Connect (OSTI)

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.

Johnson, Rolland PAUL

2014-12-31T23:59:59.000Z

306

International linear collider reference design report  

SciTech Connect (OSTI)

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.

Aarons, G.

2007-06-22T23:59:59.000Z

307

Recent Advances in Plasma Acceleration  

SciTech Connect (OSTI)

The costs and the time scales of colliders intended to reach the energy frontier are such that it is important to explore new methods of accelerating particles to high energies. Plasma-based accelerators are particularly attractive because they are capable of producing accelerating fields that are orders of magnitude larger than those used in conventional colliders. In these accelerators a drive beam, either laser or particle, produces a plasma wave (wakefield) that accelerates charged particles. The ultimate utility of plasma accelerators will depend on sustaining ultra-high accelerating fields over a substantial length to achieve a significant energy gain. More than 42 GeV energy gain was achieved in an 85 cm long plasma wakefield accelerator driven by a 42 GeV electron drive beam in the Final Focus Test Beam (FFTB) Facility at SLAC. Most of the beam electrons lose energy to the plasma wave, but some electrons in the back of the same beam pulse are accelerated with a field of {approx}52 GV/m. This effectively doubles their energy, producing the energy gain of the 3 km long SLAC accelerator in less than a meter for a small fraction of the electrons in the injected bunch. Prospects for a drive-witness bunch configuration and high-gradient positron acceleration experiments planned for the SABER facility will be discussed.

Hogan, Mark

2007-03-19T23:59:59.000Z

308

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

DOE Patents [OSTI]

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.

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

2007-01-23T23:59:59.000Z

309

Accelerator on a Chip: How It Works  

SciTech Connect (OSTI)

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.

None

2014-06-30T23:59:59.000Z

310

PROTON ACCELERATION AT OBLIQUE SHOCKS  

SciTech Connect (OSTI)

Acceleration at the shock waves propagating oblique to the magnetic field is studied using a recently developed theoretical/numerical model. The model assumes that resonant hydromagnetic wave-particle interaction is the most important physical mechanism relevant to motion and acceleration of particles as well as to excitation and damping of waves. The treatment of plasma and waves is self-consistent and time dependent. The model uses conservation laws and resonance conditions to find where waves will be generated or damped, and hence particles will be pitch-angle-scattered. The total distribution is included in the model and neither introduction of separate population of seed particles nor some ad hoc escape rate of accelerated particles is needed. Results of the study show agreement with diffusive shock acceleration models in the prediction of power spectra for accelerated particles in the upstream region. However, they also reveal the presence of spectral break in the high-energy part of the spectra. The role of the second-order Fermi-like acceleration at the initial stage of the acceleration is discussed. The test case used in the paper is based on ISEE-3 data collected for the shock of 1978 November 12.

Galinsky, V. L.; Shevchenko, V. I., E-mail: vit@ucsd.edu [ECE Department, UC San Diego, MC 407, La Jolla, CA 92093-0407 (United States)

2011-06-20T23:59:59.000Z

311

Accelerator Research Department BAccelerator Research Department B E163: Laser Acceleration  

E-Print Network [OSTI]

1 Accelerator Research Department BAccelerator Research Department B E163: Laser Acceleration, D. R. Walz Stanford Linear Accelerator Center R. L. Byer, T. Plettner Stanford University * Spokesman. #12;2 Accelerator Research Department B Outline · Introduction ­­ Future requirements for high

Wechsler, Risa H.

312

ACCELERATORS: ENGINES FOR TRAVERSING A LARGE AND OFTEN DIFFICULT LANDSCAPE  

E-Print Network [OSTI]

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

Sessler, Andrew M.

2014-01-01T23:59:59.000Z

313

Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude  

DOE Patents [OSTI]

A beam current limiter is disclosed for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity. 6 figs.

Bogaty, J.M.; Clifft, B.E.; Bollinger, L.M.

1995-08-08T23:59:59.000Z

314

Future Accelerators (?)  

E-Print Network [OSTI]

I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

John Womersley

2003-08-09T23:59:59.000Z

315

Laser acceleration of ion beams  

E-Print Network [OSTI]

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.

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

2007-02-01T23:59:59.000Z

316

Sequentially pulsed traveling wave accelerator  

DOE Patents [OSTI]

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.

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

2009-08-18T23:59:59.000Z

317

Induction accelerators for the phase rotator system  

SciTech Connect (OSTI)

The principle of magnetic induction has been applied to the acceleration of high current beams in betatrons and a variety of induction accelerators. The linear induction accelerator (LIA) consists of a simple nonresonant structure where the drive voltage is applied to an axially symmetric gap that encloses a toroidal ferromagnetic material. The change in flux in the magnetic core induces an axial electric field that provides particle acceleration. This simple nonresonant (low Q) structure acts as a single turn transformer that can accelerate from hundreds of amperes to tens of kiloamperes, basically only limited by the drive impedance. The LIA is typically a low gradient structure that can provide acceleration fields of varying shapes and time durations from tens of nanoseconds to several microseconds. The efficiency of the LIA depends on the beam current and can exceed 50% if the beam current exceeds the magnetization current required by the ferromagnetic material. The acceleration voltage available is simply given by the expression V=A dB/dt. Hence, for a given cross section of material, the beam pulse duration influences the energy gain. Furthermore, a premium is put on minimizing the diameter, which impacts the total weight or cost of the magnetic material. The diameter doubly impacts the cost of the LIA since the power (cost) to drive the cores is proportional to the volume as well. The waveform requirements during the beam pulse makes it necessary to make provisions in the pulsing system to maintain the desired dB/dt during the useful part of the acceleration cycle. This is typically done two ways, by using the final stage of the pulse forming network (PFN) and by the pulse compensation network usually in close proximity of the acceleration cell. The choice of magnetic materials will be made by testing various materials both ferromagnetic and ferrimagnetic. These materials will include the nickel-iron, silicon steel amorphous and various types of ferrites not only to determine the properties that are essential in this application but the energy losses in the magnetization process which directly impact the cost.

Reginato, Lou; Yu, Simon; Vanecek, Dave

2001-07-30T23:59:59.000Z

318

Subcritical Fission Reactor Based on Linear Collider  

E-Print Network [OSTI]

The beams of Linear Collider after main collision can be utilized to build an accelerator--driven sub--critical reactor.

I. F. Ginzburg

2005-07-29T23:59:59.000Z

319

BEAM DYNAMICS SIMULATIONS OF SARAF ACCELERATOR INCLUDING ERROR PROPAGATION AND IMPLICATIONS FOR THE EURISOL DRIVER  

E-Print Network [OSTI]

AbstractBeam dynamics simulations of SARAF (Soreq Applied Research Accelerator Facility) superconducting RF linear accelerator have been performed in order to establish the accelerator design. The multi-particle simulation includes 3D realistic electromagnetic field distributions, space charge forces and fabrication, misalignment and operation errors. A 4 mA proton or deuteron beam is accelerated up to 40 MeV with a moderated rms emittance growth and a high real-estate gradient of 2 MeV/m. An envelope of 40,000 macro-particles is kept under a radius of 1.1 cm, well below the beam pipe bore radius. The accelerator design of SARAF is proposed as an injector for the EURISOL driver accelerator. The Accel 176 MHZ ?0=0.09 and ?0=0.15 HWR lattice was extended to 90 MeV based on the LNL 352 MHZ ?0=0.31 HWR. The matching between both lattices ensures smooth transition and the possibility to extend the accelerator to the required EURISOL ion energy.

J. Rodnizki, D. Berkovits, K. Lavie, I. Mardor, A. Shor and Y. Yanay (Soreq NRC, Yavne), K. Dunkel, C. Piel (ACCEL, Bergisch Gladbach), A. Facco (INFN/LNL, Legnaro, Padova), V. Zviagintsev (TRIUMF, Vancouver)

320

E-Print Network 3.0 - accelerator physics experiments Sample...  

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

facilities for biology and material sciences. Beam physics--study of beams in accelerators... -ray facilities, and the injector linear accelerator where a pioneering...

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


321

E-Print Network 3.0 - accelerated beam experiments Sample Search...  

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

Summary: radiation facilities for biology and material sciences. Beam physics--study of beams in accelerators... -ray facilities, and the injector linear accelerator where a...

322

Visualizing Particle-in-Cell Simulation of Laser Wakefield Particle...  

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

of times greater than those obtained in conventional particle accelerators. LWFAs use the electric field of a plasma wave - the wakefield - driven by the radiation pressure of an...

323

Buffered Electropolishing – A New Way for Achieving Extremely Smooth Surface Finish on Nb SRF Cavities to be Used in Particle Accelerators  

SciTech Connect (OSTI)

Future accelerators require unprecedented cavity performance, which is strongly influenced by interior surface nano-smoothness. Electropolishing (EP) is the technique of choice to be developed for high-field superconducting radio frequency (SRF) cavities. Electrochemical impedance spectroscopy (EIS) and related techniques point to the electropolishing mechanism of Nb in a sulphuric and hydrofluoric acid electrolyte controlled by a compact surface salt film under F- diffusion-limited mass transport control. These and other findings are guiding a systematic characterization to form the basis for cavities process optimization.

Hui Tian, Charles Reece, Michael Kelley

2009-05-01T23:59:59.000Z

324

ACCELERATED LINEARIZED BREGMAN METHOD June 21, 2011 ...  

E-Print Network [OSTI]

Jun 21, 2011 ... Page 1 ... has become a topic of great interest. In compressed sensing, A is usually the product of a sensing matrix ? and a transform basis ...

2011-06-22T23:59:59.000Z

325

E-Print Network 3.0 - accelerated finite difference Sample Search...  

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

doi:10.10880953-4075389020 Summary: sources for future laser-driven particle accelerators. Several different laser-driven acceleration... 's theory of special relativity on...

326

E-Print Network 3.0 - accelerating multiply charged Sample Search...  

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

Scattering experiments are used extensively to probe the properties Summary: accelerators that have followed it, is to use electric fields to accelerate charged particles,...

327

E-Print Network 3.0 - accelerating beam stability Sample Search...  

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

(ARD) has the mission to develop accelerator Summary: between rf systems and particle beams, applications of control techniques to asses system stability... Wakefield Accelerator...

328

E-Print Network 3.0 - accelerator school beam Sample Search Results  

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

intensity? Early cyclotron... (r) 12;US Particle Accelerator School High intensity beams need non-time-varying focusing Dipole fields... Accelerator ... Source: Dai, Pengcheng...

329

E-Print Network 3.0 - accelerator mass spectroscopy Sample Search...  

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

of tens of MeV electron acceleration in the Earth's atmosphere... , and acceleration of solar energetic particles (SEPs) by shocks driven by fast coronal mass ejections (CMEs......

330

E-Print Network 3.0 - accelerator physics theory Sample Search...  

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

physics and astrophysics. It is now known that particle acceleration can occur... the small-scale acceleration physics can be incorpo- rated into the large-scale coronal...

331

LASER-PLASMA-ACCELERATOR-BASED COLLIDERS C. B. Schroeder  

E-Print Network [OSTI]

LASER-PLASMA-ACCELERATOR-BASED COLLIDERS C. B. Schroeder , E. Esarey, Cs. T´oth, C. G. R. Geddes-generation linear col- lider based on laser-plasma-accelerators are discussed, and a laser-plasma-accelerator gamma-gamma () collider is considered. An example of the parameters for a 0.5 TeV laser-plasma-accelerator collider

Geddes, Cameron Guy Robinson

332

Injection and acceleration of H at Earth's bow shock  

E-Print Network [OSTI]

Injection and acceleration of H and He2 at Earth's bow shock M. Scholer1 , H. Kucharek1 , K the injection and subsequent acceleration of part of the solar wind ions at the Earth's bow shock. The shocks particles does not contribute to ion injection. Acceleration models that permit thermal particles to scatter

Paris-Sud XI, Université de

333

Final Report: Measurements of Core Conditions, Implosion Symmetry, and Anomaloes Acceleration Mechanisms on Omega through Charged Particle Spectroscopy, November 1, 1997 - December 31, 1998  

SciTech Connect (OSTI)

This work concerns the first spectroscopic measurements of energetic charged particles on Omega. Individual line profiles include D-3He protons (14.7 MeV) and alphas (3.6 MeV), D-T alphas (3.5 MeV), D-D protons (3.0 MeV), and D-D tutons (1.0 MeV)

Petrasso, R.; Li, C.K.

1999-10-19T23:59:59.000Z

334

Accelerate Energy  

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

Accelerate Energy Productivity 2030 Over the next year, the U.S. Department of Energy, the Council on Competitiveness and the Alliance to Save Energy will join forces to undertake...

335

ACCELERATE ENERGY  

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

ACCELERATE ENERGY PRODUCTIVITY 2030 A Partnership To Double U.S. Energy Productivity By 2030 LEARN MORE AT: www.energy2030.org "I'm issuing a new goal for America: let's cut in...

336

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout the Building Technologies Office AboutAccelerateAccelerating

337

An Alternative to Particle Dark Matter  

E-Print Network [OSTI]

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.

Justin Khoury

2014-12-11T23:59:59.000Z

338

International Workshop on Linear Colliders 2010  

ScienceCinema (OSTI)

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

None

2011-10-06T23:59:59.000Z

339

Cascaded target normal sheath acceleration  

SciTech Connect (OSTI)

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.

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. [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)] [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

2013-11-15T23:59:59.000Z

340

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

E-Print Network [OSTI]

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.

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

2005-03-29T23:59:59.000Z

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


341

Accelerated Testing Validation  

E-Print Network [OSTI]

the University of California. Accelerated Testing Validationmaterials requires relevant Accelerated Stress Tests (ASTs),

Mukundan, Rangachary

2013-01-01T23:59:59.000Z

342

E-Print Network 3.0 - accelerator personnel radiatsionnye Sample...  

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

Linear Accelerator Center Collection: Physics 42 Advanced Photon Source Conduct of Operations Manual Summary: . . . . . . . . . . . . . . . . . . . 26 4.5 Beamline...

343

Accelerator Technology Division progress report, FY 1992  

SciTech Connect (OSTI)

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.

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

1993-07-01T23:59:59.000Z

344

Accelerator research studies  

SciTech Connect (OSTI)

The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the second year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' (P.I., M. Reiser); TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' (Co-P.I.'s, W.W. Destler, M. Reiser, M.J. Rhee, and C.D. Striffler); TASK C, Study of a Gyroklystron High-Power Microwave Source for Linear Colliders,'' (Co-P.I.'s, V.L. Granatstein, W. Lawson, M. Reiser, and C.D. Striffler). In this report we document the progress that has been made during the past year for each of the three tasks.

Not Available

1993-01-01T23:59:59.000Z

345

Linear Collider Physics Resource Book Snowmass 2001  

SciTech Connect (OSTI)

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.

Ronan (Editor), M.T.

2001-06-01T23:59:59.000Z

346

ACCELERATOR R&D S U M M A R Y  

E-Print Network [OSTI]

1 ACCELERATOR R&D P5 @ BNL 3/6/08 S U M M A R Y Medium & Longer Term [AARD = Advanced Accelerator R&D] #12;2 · Accelerators remain an essential component in Elementary Particle Physics Research · Accelerator capabilities are prominent in defining the frontiers of Elementary Particle Science · EPP2010

347

Fourier Accelerated Conjugate Gradient Lattice Gauge Fixing  

E-Print Network [OSTI]

We provide details of the first implementation of a non-linear conjugate gradient method for Landau and Coulomb gauge fixing with Fourier acceleration. We find clear improvement over the Fourier accelerated steepest descent method, with the average time taken for the algorithm to converge to a fixed, high accuracy, being reduced by a factor of 2 to 4.

R. J. Hudspith

2014-05-22T23:59:59.000Z

348

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

SciTech Connect (OSTI)

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.

Schroeder, C. B.; Benedetti, C.; Esarey, E.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2013-12-15T23:59:59.000Z

349

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

E-Print Network [OSTI]

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...

Codispoti, Anna

2015-01-01T23:59:59.000Z

350

E-Print Network 3.0 - accelerator experimental tests Sample Search...  

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

Collection: Physics 6 Research in: Experimental Photonuclear Physics Summary: & Phenomenology Particle Astrophysics & Cosmology Accelerator Physics Health Physics...

351

Improvement of classical accelerators by lasers  

E-Print Network [OSTI]

Of the unconventional accelerator techniques those including lasers are reported. After explaining the advances by lasers for classical accelerator techniques, as FELs and other methods for 100 GHz generation of GW pulses, a survey is given of far field and near field laser acceleration. Problems of the beat-wave accelerator are discussed and schemes for particle interaction in vacuum without plasma are elaborated. One scheme is the Boreham experiment and another is the acceleration of "standing" wave fields where charged particles are trapped in the intensity minima. Another scheme uses the relativistic acceleration by half waves where the now available petawatt-picosecond laser pulses should produce GeV electron pulses of high luminosity. Increase of these electron enrgies would need very large lasers in the future.

Hora, Heinrich

1991-01-01T23:59:59.000Z

352

Accelerator target  

DOE Patents [OSTI]

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.

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

1999-06-29T23:59:59.000Z

353

Accelerator target  

DOE Patents [OSTI]

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.

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

1999-01-01T23:59:59.000Z

354

Properties of Trapped Electron Bunches in a Plasma Wakefield Accelerator  

SciTech Connect (OSTI)

Plasma-based accelerators use the propagation of a drive bunch through plasma to create large electric fields. Recent plasma wakefield accelerator (PWFA) experiments, carried out at the Stanford Linear Accelerator Center (SLAC), successfully doubled the energy for some of the 42 GeV drive bunch electrons in less than a meter; this feat would have required 3 km in the SLAC linac. This dissertation covers one phenomenon associated with the PWFA, electron trapping. Recently it was shown that PWFAs, operated in the nonlinear bubble regime, can trap electrons that are released by ionization inside the plasma wake and accelerate them to high energies. These trapped electrons occupy and can degrade the accelerating portion of the plasma wake, so it is important to understand their origins and how to remove them. Here, the onset of electron trapping is connected to the drive bunch properties. Additionally, the trapped electron bunches are observed with normalized transverse emittance divided by peak current, {epsilon}{sub N,x}/I{sub t}, below the level of 0.2 {micro}m/kA. A theoretical model of the trapped electron emittance, developed here, indicates that the emittance scales inversely with the square root of the plasma density in the non-linear 'bubble' regime of the PWFA. This model and simulations indicate that the observed values of {epsilon}{sub N,x}/I{sub t} result from multi-GeV trapped electron bunches with emittances of a few {micro}m and multi-kA peak currents. These properties make the trapped electrons a possible particle source for next generation light sources. This dissertation is organized as follows. The first chapter is an overview of the PWFA, which includes a review of the accelerating and focusing fields and a survey of the remaining issues for a plasma-based particle collider. Then, the second chapter examines the physics of electron trapping in the PWFA. The third chapter uses theory and simulations to analyze the properties of the trapped electron bunches. Chapters four and five present the experimental diagnostics and measurements for the trapped electrons. Next, the sixth chapter introduces suggestions for future trapped electron experiments. Then, Chapter seven contains the conclusions. In addition, there is an appendix chapter that covers a topic which is extraneous to electron trapping, but relevant to the PWFA. This chapter explores the feasibility of one idea for the production of a hollow channel plasma, which if produced could solve some of the remaining issues for a plasma-based collider.

Kirby, Neil; /SLAC

2009-10-30T23:59:59.000Z

355

Accelerators for Intensity Frontier Research  

SciTech Connect (OSTI)

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.

Derwent, Paul; /Fermilab

2012-05-11T23:59:59.000Z

356

GPU accelerated cardiac electrophysiology  

E-Print Network [OSTI]

OF THE THESIS GPU Accelerated Cardiac Electrophysiology bySAN DIEGO GPU Accelerated Cardiac Electrophysiology A thesistoolkit for developing GPU accelerated programs called CUDA,

Lionetti, Fred

2010-01-01T23:59:59.000Z

357

High Power Proton Accelerators: Capabilities and  

E-Print Network [OSTI]

;Charge neutral deeply penetrating Li motion in fuel cells Help build electric cars Nuclear scattering-Battelle for the U.S. Department of Energy "Rough" Outline · Why high power proton accelerators? · Brief introduction energy to probe for smaller and smaller particles. The SNS is part of class of accelerators called

Tennessee, University of

358

Accelerator Systems  

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

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359

Numerical modeling of multi-GeV laser wakefield electron acceleration inside a dielectric capillary tube  

SciTech Connect (OSTI)

Numerical modeling of laser wakefield electron acceleration inside a gas filled dielectric capillary tube is presented. Guiding of a short pulse laser inside a dielectric capillary tube over a long distance (?1 m) and acceleration of an externally injected electron bunch to ultra-relativistic energies (?5-10 GeV) are demonstrated in the quasi-linear regime of laser wakefield acceleration. Two dimensional axisymmetric simulations were performed with the code WAKE-EP (Extended Performances), which allows computationally efficient simulations of such long scale plasma. The code is an upgrade of the quasi-static particle code, WAKE [P. Mora and T. M. Antonsen, Jr., Phys. Plasmas 4, 217 (1997)], to simulate the acceleration of an externally injected electron bunch (including beam loading effect) and propagation of the laser beam inside a dielectric capillary. The influence of the transverse electric field of the plasma wake on the radial loss of the accelerated electrons to the dielectric wall is investigated. The stable acceleration of electrons to multi-GeV energy with a non-resonant laser pulse with a large spot-size is demonstrated.

Paradkar, B. S.; Cros, B.; Maynard, G. [Laboratoire de Physique des Gaz et des Plasmas, University Paris Sud 11-CNRS, Orsay (France)] [Laboratoire de Physique des Gaz et des Plasmas, University Paris Sud 11-CNRS, Orsay (France); Mora, P. [Centre de Physique Theorique, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)] [Centre de Physique Theorique, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

2013-08-15T23:59:59.000Z

360

Community Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies  

SciTech Connect (OSTI)

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.

Spentzouris, P.; /Fermilab; Cary, J.; /Tech-X, Boulder; McInnes, L.C.; /Argonne; Mori, W.; /UCLA; Ng, C.; /SLAC; Ng, E.; Ryne, R.; /LBL, Berkeley

2011-11-14T23:59:59.000Z

Note: This page contains sample records for the topic "linear particle accelerator" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

ONE GEV BEAM ACCELERATION IN A ONE METER LONG  

E-Print Network [OSTI]

ONE GEV BEAM ACCELERATION IN A ONE METER LONG PLASMA CELL A Proposal to the Stanford Linear. A single SLC bunch is used to both induce wakefields in the one meter long plasma and to witness that are needed to apply high-gradient plasma wakefield acceleration to large scale accelerators. The one meter

362

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

363

Methods For Planning Accelerated Repeated Measures Degradation Tests  

E-Print Network [OSTI]

Methods For Planning Accelerated Repeated Measures Degradation Tests Brian P. Weaver Statistical of Statistics Iowa State University Ames, IA 50010 wqmeeker@iastate.edu September 3, 2013 Abstract Accelerated-variable accelerated repeated measures degradation test plan when the (possibly transformed) degradation is linear

364

R&D of Accelerator Structures at SLAC  

SciTech Connect (OSTI)

The research activities for accelerator structures at SLAC are reviewed including the achievement via the main linac design for the Next Linear Collider (NLC), the program adjustment after the decision of the International Linear Collider (ILC) to be based on superconducting technology, and the work progress for the ILC, photon science at SLAC and basic accelerator structure studies.

Wang, J.W.; /SLAC

2007-01-17T23:59:59.000Z

365

Accelerators and the Accelerator Community  

SciTech Connect (OSTI)

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.

Malamud, Ernest; Sessler, Andrew

2008-06-01T23:59:59.000Z

366

A theory of metrics with maximal acceleration  

E-Print Network [OSTI]

We present a geometric theory for spacetimes whose world lines associated with physical particles have an upper bound for the proper acceleration. After some fundamental remarks on the requirements that classical dynamics for point particles must hold good, the notion of generalized metric and a theory of maximal acceleration are introduced. A perturbative approach to metrics of maximal acceleration is discussed. Then several of their physical and kinematical properties are investigated. These include a discussion of the fundamental causal theory concepts and the introduction of the associated notions of Euclidean length and celerity function. Finally, we discuss the corresponding modification of the Einstein's mass-energy relation.

Ricardo Gallego Torromé

2014-03-06T23:59:59.000Z

367

SuperB Progress Report for Accelerator  

SciTech Connect (OSTI)

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.

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.; /Frascati; 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

2012-02-14T23:59:59.000Z

368

Accelerators, Electrodynamics  

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

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369

Application 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout theOFFICEAmesApplication Acceleration on Current and Future Cray

370

Commnity Petascale Project for Accelerator Science And Simulation: Advancing Computational Science for Future Accelerators And Accelerator Technologies  

SciTech Connect (OSTI)

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.

Spentzouris, Panagiotis; /Fermilab; Cary, John; /Tech-X, Boulder; Mcinnes, Lois Curfman; /Argonne; Mori, Warren; /UCLA; Ng, Cho; /SLAC; Ng, Esmond; Ryne, Robert; /LBL, Berkeley

2011-10-21T23:59:59.000Z

371

Electrostatic wire stabilizing a charged particle beam  

DOE Patents [OSTI]

In combination with a charged particle beam generator and accelerator, apparatus and method are provided for stabilizing a beam of electrically charged particles. A guiding means, disposed within the particle beam, has an electric charge induced upon it by the charged particle beam. Because the sign of the electric charge on the guiding means and the sign of the particle beam are opposite, the particles are attracted toward and cluster around the guiding means to thereby stabilize the particle beam as it travels.

Prono, D.S.; Caporaso, G.J.; Briggs, R.J.

1983-03-21T23:59:59.000Z

372

Accelerating classical charges and the equivalence principle  

E-Print Network [OSTI]

We compare the behavior of a charged particle in a gravitational field and empty space. We resolve the apparent conflict between the Lorentz-Dirac equation and Larmor's formula of radiation by noting that the former describes an electron that is itself accelerated by an electromagnetic field. If instead, a hypothetical particle is considered that is accelerated by a non-electromagnetic force, Larmor's formula is found to be consistent with the accelerating particle's equation of motion. We consider the consequences concerning the equivalence principle and find that it is indeed violated if one demands that the same electromagnetic field be present in both the gravitational and accelerating cases; however, if one allows for the external electromagnetic fields to be different, the validity of the equivalence principle is restored. In either case, the basic idea behind the equivalence principle, which leads to a geometrized theory of gravity, remains unaffected.

Viktor T. Toth

2014-04-10T23:59:59.000Z

373

Electron Cloud Effects in Accelerators  

SciTech Connect (OSTI)

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].

Furman, M.A.

2012-11-30T23:59:59.000Z

374

Final Report: Particle Physics Research Program  

SciTech Connect (OSTI)

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.

Karchin, Paul E.

2011-09-01T23:59:59.000Z

375

LASER ACCELERATION IN VACUUM J.L. Hsu, T. Katsouleas  

E-Print Network [OSTI]

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

Wurtele, Jonathan

376

How Particle Accelerators Work | Department of Energy  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr FlickrGuidedCH2MLLC HistoryVeterans |Virtual Community

377

Gerig to Chair Particle Accelerator School Board  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Big Sky Learning FunNeuTel2011ProgrammaticUpdateScaling to*PDSFA

378

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region service area. TheEPSCI Home ItDark Energy

379

Ultra-High Gradient Dielectric Wakefield Accelerator Experiments  

SciTech Connect (OSTI)

Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {micro}m/OD = 325 {micro}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

Thompson, M C; Badakov, H; Rosenzweig, J B; Travish, G; Hogan, M; Ischebeck, R; Kirby, N; Siemann, R; Walz, D; Muggli, P; Scott, A; Yoder, R

2006-08-04T23:59:59.000Z

380

Ultra-High Gradient Dielectric Wakefield Accelerator Experiments  

SciTech Connect (OSTI)

Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}z = 20 {mu}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {mu}m / OD = 325 {mu}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

Thompson, M. C. [Lawrence Livermore National Laboratory, Livermore, California, 90095 (United States); Badakov, H.; Rosenzweig, J. B.; Travis, G. [UCLA Department of Physics and Astronomy, Los Angeles, California, 90095 (United States); Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D. [Stanford Linear Accelerator Center, Stanford, California, 94309 (United States); Muggli, P. [University of Southern California Los Angeles, California, 90089 (United States); Scott, A. [UCSB Department of Physics, Santa Barbara, California, 93106 (United States); Yoder, R. [Manhattan College, Riverdale, New York, 10471 (United States)

2006-11-27T23:59:59.000Z

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


381

Charged relativistic fluids and non-linear electrodynamics  

E-Print Network [OSTI]

The electromagnetic fields in Maxwell's theory satisfy linear equations in the classical vacuum. This is modified in classical non-linear electrodynamic theories. To date there has been little experimental evidence that any of these modified theories are tenable. However with the advent of high-intensity lasers and powerful laboratory magnetic fields this situation may be changing. We argue that an approach involving the self-consistent relativistic motion of a smooth fluid-like distribution of matter (composed of a large number of charged or neutral particles) in an electromagnetic field offers a viable theoretical framework in which to explore the experimental consequences of non-linear electrodynamics. We construct such a model based on the theory of Born and Infeld and suggest that a simple laboratory experiment involving the propagation of light in a static magnetic field could be used to place bounds on the fundamental coupling in that theory. Such a framework has many applications including a new description of the motion of particles in modern accelerators and plasmas as well as phenomena in astrophysical contexts such as in the environment of magnetars, quasars and gamma-ray bursts.

T. Dereli; R. W. Tucker

2010-01-08T23:59:59.000Z

382

Exact analysis of particle dynamics in combined field of finite duration laser pulse and static axial magnetic field  

SciTech Connect (OSTI)

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.

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

2012-11-15T23:59:59.000Z

383

Teleportation of Accelerated Information  

E-Print Network [OSTI]

A theoretical quantum teleportation protocal is suggested to teleport accelerated and non-accelerated information over different classes of accelerated quantum channels. For the accelerated information, it is shown that the fidelity of the teleported state increases as the entanglement of the initial quantum channel increases. However as the difference between the accelerated channel and the accelerated information decreases the fidelity increases. The fidelity of the non accelerated information increases as the entanglement of the initial quantum channel increases, while the accelerations of the quantum channel has a little effect. The possibility of sending quantum information over accelerated quantum channels is much better than sending classical information.

N. Metwally

2012-06-17T23:59:59.000Z

384

The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part 1: Overview  

E-Print Network [OSTI]

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...

Billing, M G

2015-01-01T23:59:59.000Z

385

APT accelerator. Topical report  

SciTech Connect (OSTI)

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.

Lawrence, G.; Rusthoi, D. [comp.] [ed.

1995-03-01T23:59:59.000Z

386

for sequence accelerators  

E-Print Network [OSTI]

Wynn's -algorithm for sequence accelerators using high precision arithmetic Rachel Baumann University of Arizona Wynn's -algorithm for sequence accelerators using high precision arithmetic Rachel Baumann University of Arizona April 17, 2012 #12;Wynn's -algorithm for sequence accelerators using high

Zakharov, Vladimir

387

High-Current Accelerators  

E-Print Network [OSTI]

F i g . 13 F i g . 14 A 48 ACCELERATOR F i g . 25 F i g . 16supply. Extrapolation of accelerator energy and current9 . A-48 high-current accelerator, low-velocity end. Fig.

Lawrence, Ernest O.

1955-01-01T23:59:59.000Z

388

Accelerator and electrodynamics capability review  

SciTech Connect (OSTI)

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.

Jones, Kevin W [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

389

Compensation Techniques in Accelerator Physics  

SciTech Connect (OSTI)

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.

Hisham Kamal Sayed

2011-05-31T23:59:59.000Z

390

A one-dimensional Fermi accelerator model with moving wall described by a nonlinear van der Pol oscillator  

E-Print Network [OSTI]

A modification of the one-dimensional Fermi accelerator model is considered in this work. The dynamics of a classical particle of mass $m$, confined to bounce elastically between two rigid walls where one is described by a non-linear van der Pol type oscillator while the other one is fixed, working as a re-injection mechanism of the particle for a next collision, is carefully made by the use of a two-dimensional non-linear mapping. Two cases are considered: (i) the situation where the particle has mass negligible as compared to the mass of the moving wall and does not affect the motion of it; (ii) the case where collisions of the particle does affect the movement of the moving wall. For case (i) the phase space is of mixed type leading us to observe a scaling of the average velocity as a function of the parameter ($\\c{hi}$) controlling the non-linearity of the moving wall. For large $\\c{hi}$, a diffusion on the velocity is observed leading us to conclude that Fermi acceleration is taking place. On the other hand for case (ii), the motion of the moving wall is affected by collisions with the particle. However due to the properties of the van der Pol oscillation, the moving wall relaxes again to a limit cycle. Such kind of motion absorbs part of the energy of the particle leading to a suppression of the unlimited energy gain as observed in case (i). The phase space shows a set of attractors of different periods whose basin of attraction has a complicate organization.

Tiago Botari; Edson Denis Leonel

2012-06-18T23:59:59.000Z

391

Accelerating an adiabatic process by nonlinear sweeping  

E-Print Network [OSTI]

We investigate the acceleration of an adiabatic process with the same survival probability of the ground state by sweeping a parameter nonlinearly, fast in the wide gap region and slow in the narrow gap region, as contrast to the usual linear sweeping. We find the expected acceleration in the Laudau-Zener tunneling model and in the adiabatic quantum computing model for factorizing the number N=21.

Xingxin Cao; Jun Zhuang; X. -J. Ning; Wenxian Zhang

2012-01-10T23:59:59.000Z

392

Muon Collider Progress: Accelerators  

E-Print Network [OSTI]

A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 \\times 10^34 cm^-2s^-1. Secondly, the beam is initially produced with a large 6D phase space, which necessitates a scheme for reducing the muon beam emittance ("cooling"). Finally, the muon has a short lifetime so all beam manipulations must be done very rapidly. The Muon Accelerator Program, led by Fermilab and including a number of U.S. national laboratories and universities, has undertaken design and R&D activities aimed toward the eventual construction of a muon collider. Design features of such a facility and the supporting R&D program are described.

Michael S. Zisman

2011-09-14T23:59:59.000Z

393

Nonparaxial Mathieu and Weber accelerating beams  

E-Print Network [OSTI]

We demonstrate both theoretically and experimentally nonparaxial Mathieu and Weber accelerating beams, generalizing the concept of previously found accelerating beams. We show that such beams bend into large angles along circular, elliptical or parabolic trajectories but still retain nondiffracting and self-healing capabilities. The circular nonparaxial accelerating beams can be considered as a special case of the Mathieu accelerating beams, while an Airy beam is only a special case of the Weber beams at the paraxial limit. Not only generalized nonparaxial accelerating beams open up many possibilities of beam engineering for applications, but the fundamental concept developed here can be applied to other linear wave systems in nature, ranging from electromagnetic and elastic waves to matter waves.

Peng Zhang; Yi Hu; Tongcang Li; Drake Cannan; Xiaobo Yin; Roberto Morandotti; Zhigang Chen; Xiang Zhang

2012-10-23T23:59:59.000Z

394

A new relativistic kinematics of accelerated systems  

E-Print Network [OSTI]

We consider transformations between uniformly accelerated systems, assuming that the Clock Hypothesis is false. We use the proper velocity-time description of events rather than the usual space-time description in order to obtain linear transformations. Based on the generalized principle of relativity and the ensuing symmetry, we obtain transformations of Lorentz-type. We predict the existence of a maximal acceleration and time dilation due to acceleration. We also predict a Doppler shift due to acceleration of the source in addition to the shift due to the source's velocity. Based on our results, we explain the W. K\\"{u}ndig experiment, as reanalyzed by Kholmetski \\textit{et al}, and obtain an estimate of the maximal acceleration.

Yaakov Friedman; Yuriy Gofman

2005-09-01T23:59:59.000Z

395

High-brightness H/sup -/ accelerators  

SciTech Connect (OSTI)

Neutral particle beam (NPB) devices based on high-brightness H/sup -/ accelerators are an important component of proposed strategic defense systems. The basic rationale and R and D program are outlined and examples given of the underlying technology thrusts toward advanced systems. Much of the research accomplished in the past year is applicable to accelerator systems in general; some of these activities are discussed.

Jameson, R.A.

1987-01-01T23:59:59.000Z

396

I. ACCELERATION A. Introduction  

E-Print Network [OSTI]

I. ACCELERATION A. Introduction Following cooling and initial bunch compression, the beams must be rapidly accelerated. The acceleration needed for a Higgs collider is probably the most conventional part undertaken. A sequence of linacs would work, but would be expensive. Some form of circulating acceleration

McDonald, Kirk

397

Superconducting Radiofrequency (SRF) Accelerator Cavities  

ScienceCinema (OSTI)

Charlie Reece, an accelerator technology scientist, explains how superconducting radiofrequency accelerator cavities work.

Reece, Charlie

2014-05-22T23:59:59.000Z

398

Acceleration time scale at ultrarelativistic shock waves  

E-Print Network [OSTI]

The first-order cosmic ray acceleration at ultrarelativistic shocks is investigated using the Monte Carlo method. We apply a method of discrete particle momentum scattering as a model of particle pitch angle diffusion to reproduce highly anisotropic conditions at the shock wave. Shocks with Lorentz factors $\\gamma$ up to 320 and varying magnetic field inclinations $\\psi$ are considered. Values of diffusion coefficients upstream in the point where energy spectral indices stabilize to the limit 2.2 were calculated. The obtained acceleration time does not depend on shock conditions.

J. Bednarz

1998-08-26T23:59:59.000Z

399

Perpendicular ion acceleration in whistler turbulence  

SciTech Connect (OSTI)

Whistler turbulence is an important contributor to solar wind turbulence dissipation. This turbulence contains obliquely propagating whistler waves at electron scales, and these waves have electrostatic components perpendicular to the mean magnetic field. In this paper, a full kinetic, two-dimensional particle-in-cell simulation shows that whistler turbulence can accelerate ions in the direction perpendicular to the mean magnetic field. When the ions pass through wave-particle resonances region in the phase space during their cyclotron motion, the ions are effectively accelerated in the perpendicular direction. The simulation results suggest that whistler turbulence contributes to the perpendicular heating of ions observed in the solar wind.

Saito, S. [Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464-8601 (Japan)] [Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464-8601 (Japan); Nariyuki, Y. [Faculty of Human Development, University of Toyama, 3190, Toyama 930-8555 (Japan)] [Faculty of Human Development, University of Toyama, 3190, Toyama 930-8555 (Japan)

2014-04-15T23:59:59.000Z

400

E-Print Network 3.0 - accelerator-based facility design Sample...  

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

Planning: Assumed to hold flat for next few years. * Proton Accelerator-Based Physics - ATLAS... Facility Department - Linear Collider Department is focused on the design of ......

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


401

E-Print Network 3.0 - accelerating polarized beams Sample Search...  

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

polarized beams Search Powered by Explorit Topic List Advanced Search Sample search results for: accelerating polarized beams Page: << < 1 2 3 4 5 > >> 1 Linear Collider...

402

Krylov Subspace Accelerated Algebraic Multigrid for Mimetic Finite Differences on GPUs.  

E-Print Network [OSTI]

?? The topic of this thesis is GPU accelerated sparse linear algebra for subsurface reservoir modeling. Numerical techniques for reservoir sim- ulations are described and… (more)

Lřnsethagen, Simen Andreas Andreassen

2012-01-01T23:59:59.000Z

403

Development of a Charged Particle Microbeam for Targeted and Single Particle Subcellular Irradiation  

SciTech Connect (OSTI)

The development of a charged particle microbeam for single particle, subcellular irradiations at the Massachusetts Institute of Technology Laboratory for Accelerator Beam Applications (MIT LABA) was initiated under this NEER aeard. The Microbeam apparatus makes use of a pre-existing electrostatic accelerator with a horizontal beam tube.

Yanch, Jacquelyn C.

2004-03-12T23:59:59.000Z

404

Petawatt pulsed-power accelerator  

DOE Patents [OSTI]

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.

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)

2010-03-16T23:59:59.000Z

405

acceleration cavity tuner: Topics by E-print Network  

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

power proton linear accelerators. In terms of structure design, a triple-spoke superconduct- ing cavity of the proton linac in the Eurisol project 3. Meanwhile, the study of...

406

Laser-PlasmaWakefield Acceleration with Higher Order Laser Modes  

E-Print Network [OSTI]

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.

Geddes, C.G.R.

2011-01-01T23:59:59.000Z

407

High-energy lattice for first-beam operation of the SRF test accelerator at NML  

SciTech Connect (OSTI)

The Superconducting Radio Frequency Test Accelerator, a linear electron accelerator currently in construction at Fermilab's New Muon Laboratory, will eventually reach energies of {approx} 900 MeV using four ILC-type superconducting accelerating cryomodules. The accelerator's construction is staged according to cryomodules availability. The first phase that will support first beam operation incorporates one cryomodule. In this Note, we summarize a possible design for the first-beam accelerator configuration.

Prokop, C.; /NICADD, DeKalb; Piot, P.; /NICADD, DeKalb /Fermilab; Church, M.; /Fermilab

2011-09-01T23:59:59.000Z

408

Acceleration and vortex filaments in turbulence  

E-Print Network [OSTI]

We report recent results from a high resolution numerical study of fluid particles transported by a fully developed turbulent flow. Single particle trajectories were followed for a time range spanning more than three decades, from less than a tenth of the Kolmogorov time-scale up to one large-eddy turnover time. We present some results concerning acceleration statistics and the statistics of trapping by vortex filaments.

F. Toschi; L. Biferale; G. Boffetta; A. Celani; B. J. Devenish; A. Lanotte

2005-01-23T23:59:59.000Z

409

Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m  

ScienceCinema (OSTI)

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.

None

2013-05-28T23:59:59.000Z

410

Acclerator R&D for a Linear Collider  

SciTech Connect (OSTI)

The goal of this project was to perform simulations of beam transport in linear colliders, with an emphasis on emittance dilution, spin polarization transport, and development and testing of beam based tuning algorithms. Our simulations are based on an existing object-oriented particle-tracking library, Bmad. To facilitate the efficient development of simulations, an accelerator design and analysis program based on Bmad has been developed called Tao (Tool for Accelerator Optics). The three beam-based alignment algorithms, Dispersion Free Steering, Ballistic Alignment (BA), and the Kubo Method have been implemented in Tao. We have studied the effects of magnet misalignments, BPM resolution, beam jitter, stray fields, BPM and steering magnet failure and the effects of various cavity shape wakefields. A parametric study has been conducted in the presence of the above types of errors for all three alignment algorithms. We find that BPM resolution has only modest impact on the effectiveness of beam based alignment. The DFS correction algorithm was found to be very robust in situations where there were BPM and/or steering magnet failures. The wakefields in the main linac are very weak and cause negligible emittance growth. Spin tracking was extended to study all accelerator components between the damping ring and the interaction point, including RF cavities and the helical undulator. We find that there is no significant depolarization in the RTML, main linac or beam delivery system and that the polarization is relatively insensitive to misalignment. We have developed an effective spin rotator. During the final year of the grant we exploited the computing power of our new linux cluster, along with the modeling codes that we had developed, to investigate damping ring physics and design, specifically as it relates to the CESR Test Accelerator project.

Rubin, D.L.; Dugan, G.; Gibbons, L.; Palmer, M.; Patterson, R.; Sagan, D.; Smith, J.C.; Tenenbaum, P.; Woodley, M.; Fields, J.; Urban, J.

2008-11-26T23:59:59.000Z

411

Direct laser acceleration of electrons in free-space  

E-Print Network [OSTI]

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...

Carbajo, Sergio; Wong, Liang Jie; Miller, R J Dwayne; Kärtner, Franz X

2015-01-01T23:59:59.000Z

412

U.S. Department of Energy and India Partner to Advance Accelerator...  

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

"Working together, we will be able to further our collective understanding of accelerators and high-energy particles, pursue new technologies and scientific discoveries, and...

413

E-Print Network 3.0 - accelerated molecular dynamics Sample Search...  

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

77 Summary: . The molecular synchrotron1 is analogous to charged-particle accelerators. It borrows the techniques of high... electronic potentials governing the dynamics...

414

E-Print Network 3.0 - acceleration mechanics Sample Search Results  

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

Undergraduate E&M Undergraduate Mechanics Text Book: An Introduction to Particle Accelerators... Physics 309, The University of Chicago, Winter 2003 INTRODUCTION TO ... Source:...

415

E-Print Network 3.0 - accelerators devices Sample Search Results  

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

Search Powered by Explorit Topic List Advanced Search Sample search results for: accelerators devices Page: << < 1 2 3 4 5 > >> 1 The Application of Radiation and Particle Beams...

416

E-Print Network 3.0 - autoresonant acceleration proof-of-principle...  

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

of autoresonant continuously phase-locked Bernstein... is an important goal of plasma research. For example, such waves can be used for charged particle acceleration1 Source:...

417

E-Print Network 3.0 - accelerator applications university Sample...  

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

university Page: << < 1 2 3 4 5 > >> 1 The Application of Radiation and Particle Beams from Laser Plasma Wakefield Accelerators to Oncology Summary: The Application of...

418

E-Print Network 3.0 - athens tandem accelerator Sample Search...  

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

results for: athens tandem accelerator Page: << < 1 2 3 4 5 > >> 1 Workshop on Thermonuclear Reaction Rates for Astrophysics Applications Summary: , particle physics, neutrino...

419

E-Print Network 3.0 - accelerator neutron source Sample Search...  

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

driven by a powerful particle accelerator. This intense neutron source... . In subcritical systems driven by an intense external source of neutrons - in ADS. An external...

420

Jefferson Lab Fall Lecture: Exploring Our World With Particle...  

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

Fall Lecture: Exploring Our World With Particle Accelerators NEWPORT NEWS, Va., Nov. 9, 2010 - Jefferson Lab's 2010 Fall Science Lecture Series concludes on Tuesday, Nov. 23, with...

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


421

Use of dielectric material in muon accelerator RF cavities  

E-Print Network [OSTI]

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 ...

French, Katheryn Decker

2011-01-01T23:59:59.000Z

422

Testing General Relativity With Laser Accelerated Electron Beams  

E-Print Network [OSTI]

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.

L. Á. Gergely; T. Harko

2012-07-16T23:59:59.000Z

423

Testing general relativity with laser accelerated electron beams  

SciTech Connect (OSTI)

Electron accelerations of the order of 10{sup 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.

Gergely, L. A.; Harko, T. [Department of Theoretical Physics, University of Szeged, Szeged 6720, Tisza L. krt. 84, Hungary and Department of Experimental Physics, University of Szeged, 6720 Szeged, Dom ter 9 (Hungary); Department of Physics and Center for Theoretical and Computational Physics, University of Hong Kong, Pok Fu Lam Road (Hong Kong)

2012-07-09T23:59:59.000Z

424

Particles in Surface Waters: Coagulation and Transport  

E-Print Network [OSTI]

Conventional water quality assessment and simulation of particles in natural waters focus on bulk concentrations of the suspended solid phase. These analyses rely directly or indirectly on a linear, 'average particle' approach to describe processes...

Culkin, Gerald W.; Lawler, Desmond F.

425

Accelerator R&D  

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

(505) 667-5657 Email Accelerator R&D R&D model Figure 1: Conceptual drawing of a superconducting radio-frequency accelerator with a PBG coupler cell. The ultimate goal of this...

426

Radiation from Kinetic Poynting Flux Acceleration  

E-Print Network [OSTI]

We derive analytic formulas for the power output and critical frequency of radiation by electrons accelerated by relativistic kinetic Poynting flux, and validate these results with Particle-In-Cell plasma simulations. We find that the in-situ radiation power output and critical frequency are much below those predicted by the classical synchrotron formulae. We discuss potential astrophysical applications of these results.

Edison Liang; Koichi Noguchi

2007-11-18T23:59:59.000Z

427

LARGE-APERTURE D- ACCELERATORS  

E-Print Network [OSTI]

Vignetted current profile at accelerator entrance aperture 'LARGE-APERTURE D" ACCELERATORS* 0. A. Anderson" " Lawrencen i a 9-1720 Abstract Accelerator designs are described for

Anderson, O.A.

2010-01-01T23:59:59.000Z

428

Beam Dynamics for Induction Accelerators  

E-Print Network [OSTI]

Dynamics for Induction Accelerators Edward P. Lee Lawrencea natural candidate accelerator for a heavy ion fusion (HIF)words: Fusion, Induction, Accelerators, Dynamics This work

Lee, E.P.

2014-01-01T23:59:59.000Z

429

Generic Quantum Ratchet Accelerator with Full Classical Chaos  

E-Print Network [OSTI]

A simple model of quantum ratchet transport that can generate unbounded linear acceleration of the quantum ratchet current is proposed, with the underlying classical dynamics fully chaotic. The results demonstrate that generic acceleration of quantum ratchet transport can occur with any type of classical phase space structure. The quantum ratchet transport with full classical chaos is also shown to be very robust to noise due to the large linear acceleration afforded by the quantum dynamics. One possible experiment allowing observation of these predictions is suggested.

Jiangbin Gong; Paul Brumer

2006-09-05T23:59:59.000Z

430

E-Print Network 3.0 - accelerator beam dumps Sample Search Results  

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

RECOVERY LINACS G.H. Hoffstaetter Summary: (ERLs) accelerate high-current particle beams to high energy in a linac. These are then used in x... of particles. Only with such...

431

Photonic Crystal Laser-Driven Accelerator Structures  

SciTech Connect (OSTI)

Laser-driven acceleration holds great promise for significantly improving accelerating gradient. However, scaling the conventional process of structure-based acceleration in vacuum down to optical wavelengths requires a substantially different kind of structure. We require an optical waveguide that (1) is constructed out of dielectric materials, (2) has transverse size on the order of a wavelength, and (3) supports a mode with speed-of-light phase velocity in vacuum. Photonic crystals---structures whose electromagnetic properties are spatially periodic---can meet these requirements. We discuss simulated photonic crystal accelerator structures and describe their properties. We begin with a class of two-dimensional structures which serves to illustrate the design considerations and trade-offs involved. We then present a three-dimensional structure, and describe its performance in terms of accelerating gradient and efficiency. We discuss particle beam dynamics in this structure, demonstrating a method for keeping a beam confined to the waveguide. We also discuss material and fabrication considerations. Since accelerating gradient is limited by optical damage to the structure, the damage threshold of the dielectric is a critical parameter. We experimentally measure the damage threshold of silicon for picosecond pulses in the infrared, and determine that our structure is capable of sustaining an accelerating gradient of 300 MV/m at 1550 nm. Finally, we discuss possibilities for manufacturing these structures using common microfabrication techniques.

Cowan, Benjamin M.

2007-08-22T23:59:59.000Z

432

Beyond the Desert 2002, Accelerator, Non--Accelerator and Space Approaches in the New Millenium  

E-Print Network [OSTI]

The third conference on particle physics beyond the Standard Model (BEYOND THE DESERT'02 - Accelerator, Non-accelerator and Space Approaches) was held during 2--7 June, 2002 at the Finish town of Oulu, almost at the northern Arctic Circle. It was the first of the BEYOND conference series held outside Germany (CERN Courier March 2003, pp. 29-30). Traditionally the Scientific Programme of BEYOND conferences, brought into life in 1997 (see CERN Courier, November 1997, pp.16-18), covers almost all topics of modern particle physics (see contents).

H. V. Klapdor Kleingrothaus

2004-04-06T23:59:59.000Z

433

Combined gravitational and electromagnetic self-force on charged particles in electrovac spacetimes  

E-Print Network [OSTI]

We consider the self-force on a charged particle moving in a curved spacetime with a background electromagnetic field, extending previous studies to situations in which gravitational and electromagnetic perturbations are comparable. The formal expression $f^{ret}_\\alpha$ for the self-force on a particle, written in terms of the retarded perturbed fields, is divergent, and a renormalization is needed to find the particle's acceleration at linear order in its mass $m$ and charge $e$. We assume that, as in previous work in a Lorenz gauge, the renormalization for accelerated motion comprises an angle average and mass renormalization. Using the short distance expansion of the perturbed electromagnetic and gravitational fields, we show that the renormalization is equivalent to that obtained from a mode sum regularization in which one subtracts from the expression for the self-force in terms of the retarded fields a singular part field comprising only the leading and subleading terms in the mode sum. The most striking part of our result, arising from a remarkable cancellation, is that the renormalization involves no mixing of electromagnetic and gravitational fields. In particular, the renormalized mass is obtained by subtracting (1) the purely electromagnetic contribution from a point charge moving along an accelerated trajectory and (2) the purely gravitational contribution from a point mass moving along the same trajectory. In a mode-sum regularization, the same cancellation implies that the required regularization parameters are sums of their purely electromagnetic and gravitational values.

Thomas M. Linz; John L. Friedman; Alan G. Wiseman

2014-06-19T23:59:59.000Z

434

Acceleration and Parallax Effects in Gravitational Microlensing  

E-Print Network [OSTI]

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.

M. C. Smith; S. Mao; B. Paczynski

2003-01-27T23:59:59.000Z

435

Study of quark fragmentation in e(+)e(-) annihilation at 29 GeV: Global jet parameters and single-particle distributions  

E-Print Network [OSTI]

PARTICLES AND FIELDS THIRD SERIES, VOLUME 31, NUMBER 1 1 JANUARY 1985 Study of quark fragmentation in e+e annihilation at 29 GeV: Global jet parameters and single-particle distributions D. Bender, "M. Derrick, E. Fernandez, '"' R. Fries,". G..., California 94720 L. Keller and J. Va'vra Stanford Linear Accelerator Center, Stanford, California 94305 (Received 21 May 1984) In this paper, results are presented fram a study of the hadronic final states in e+e annihilation at 29 GeV. The data were obtained...

Baringer, Philip S.

1985-01-01T23:59:59.000Z

436

Beam dynamics in accelerators for medical applications: from calculations to machine performance  

E-Print Network [OSTI]

Beam dynamics in accelerators for medical applications: from calculations to machine performance S, z', W, RF-phase) at each time-moment for each particle in the accelerating bunch use cylindrical, Novosibirsk, Russian Federation #12;Main results of calculations 6 ...transverse beam size during acceleration

437

Accelerated Electrons as the Source of Auroral Kilometric Radiation R. J. Strangeway  

E-Print Network [OSTI]

Accelerated Electrons as the Source of Auroral Kilometric Radiation R. J. Strangeway Institute-04, presented at the 2nd EGS Alfvén Conference on Auroral Particle Acceleration, 3-7 May 1999, Stockholm, Sweden) have confirmed that Auroral Kilometric Radiation (AKR) is generated by the accelerated electrons

Strangeway, Robert J.

438

SLAC low emittance accelerator test facility  

SciTech Connect (OSTI)

SLAC is proposing to build a new Accelerator Test Facility (ATF) capable of producing a 50 MeV electron beam with an extremely low geometric tranverse emittance (1.5 x 10/sup -10/ rad.m) for the purpose of testing new methods of acceleration. The low emittance will be achieved by assembling a linear accelerator using one standard SLAC three-meter section and a 400 kV electron gun with a very small photocathode (40 microns in diameter). The photocathode will be illuminated from the back by short bursts (on the order of 6 ps) of visible laser light which will produce bunches of about 10/sup 5/ electrons. Higher currents could be obtained by illuminating the cathode from the front. The gun will be mounted directly against the accelerator section. Calculations show that in the absence of an rf buncher, injection of these 400 keV small radius electron bunches roughly 30/sup 0/ ahead of crest produces negligible transverse emittance growth due to radial rf forces. Acceleration of the electrons up to 50 MeV followed by collimation, energy slits and focusing will provide a 3.2 mm long waist of under 1.5 ..mu..m in diameter where laser acceleration and other techniques can be tested.

Loew, G.A.; Miller, R.H.; Sinclair, C.K.

1986-05-01T23:59:59.000Z

439

Ion Acceleration by Short Chirped Laser Pulses  

E-Print Network [OSTI]

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.

Li, Jian-Xing; Keitel, Christoph H; Harman, Zoltán

2015-01-01T23:59:59.000Z

440

Effect of plasma inhomogeneity on plasma wakefield acceleration driven by long bunches  

SciTech Connect (OSTI)

Effects of plasma inhomogeneity on self-modulating proton bunches and accelerated electrons were studied numerically. The main effect is the change of the wakefield wavelength which results in phase shifts and loss of accelerated particles. This effect imposes severe constraints on density uniformity in plasma wakefield accelerators driven by long particle bunches. The transverse two stream instability that transforms the long bunch into a train of micro-bunches is less sensitive to density inhomogeneity than are the accelerated particles. The bunch freely passes through increased density regions and interacts with reduced density regions.

Lotov, K. V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia and Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Pukhov, A. [Institut fuer Theoretische Physik I, Heinrich-Heine-Universitaet Duesseldorf, 40225 Duesseldorf (Germany); Caldwell, A. [Max-Planck-Institut fuer Physik, 80805 Muenchen (Germany)

2013-01-15T23:59:59.000Z

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


441

Optically pulsed electron accelerator  

DOE Patents [OSTI]

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.

Fraser, J.S.; Sheffield, R.L.

1985-05-20T23:59:59.000Z

442

A world of hope through accelerator-based science and technologies.  

E-Print Network [OSTI]

a 6-MV Tandem Accelerator. Particle beams delivered by the accelerator are used for low energy nuclear nuclear reactions with various solid targets. #12;Particle therapy PROGRAMME #12;iThemba LABS is the only radionuclides, radiopharmaceuticals for nuclear medicine and mainstream radiopharmaceuticals for positron

Wagner, Stephan

443

Multimode Analysis of the Hollow Plasma Channel Wakefield Accelerator C. B. Schroeder,1  

E-Print Network [OSTI]

by resonant excitation [1]. In conventional accelerators, the size of these accel- erating fields is limited particle beam. For the laser wakefield accelerator one of the most se- vere limitations is the weakening- neous plasma. These properties make it well suited as a structure for both particle beam wakefield

Geddes, Cameron Guy Robinson

444

Under consideration for publication in J. Plasma Phys. 1 Plasma acceleration by the interaction of  

E-Print Network [OSTI]

efficiency. This work is based on particle-in-cell (PIC) numerical simulations and on analytical non electromagnetic fields consistent with the theory, and they show that the particle acceleration result in plasma Acceler- ation by Parallel Alfv´en Waves Interactions (APAWI). Most of the known Alfv´enic acceleration

Boyer, Edmond

445

Particle Astrophysics  

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

Particle Astrophysics Particle Astrophysics Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664 Email Bruce Carlsten...

446

Market Acceleration (Fact Sheet)  

SciTech Connect (OSTI)

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

Not Available

2010-09-01T23:59:59.000Z

447

Accelerating into the Future Zero to 1GeV in a Few Centimeters  

ScienceCinema (OSTI)

July 8, 2008 Berkeley Lab lecture: By exciting electric fields in plasma-based waveguides, lasers accelerate electrons in a fraction of the distance conventional accelerators require. The Accelerator and Fusion Research Division's LOASIS program, headed by Wim Leemans, has used 40-trillion-watt laser pulses to deliver billion-electron-volt (1 GeV) electron beams within centimeters. Leemans looks ahead to BELLA, 10-GeV accelerating modules that could power a future linear collider.

LBNL

2009-09-01T23:59:59.000Z

448

Confined energy distribution for charged particle beams  

DOE Patents [OSTI]

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.

Jason, Andrew J. (Los Alamos, NM); Blind, Barbara (Los Alamos, NM)

1990-01-01T23:59:59.000Z

449

13S C I D A C R E V I E W S U M M E R 2 0 0 9 W W W . S C I D A C R E V I E W . O R G LASER P LASM A PART ICLE ACCELERATORS  

E-Print Network [OSTI]

A PART ICLE ACCELERATORS Compared to conventional particle accelerators, plasmas can sustain accelerating simulations provide physical insight into the development of next-generation accelerators that use laser-driven plasma waves. These plasma- based accelerators offer a path to more compact, ultra-fast particle

Knowles, David William

450

Field Emission in CEBAF's SRF Cavities and Implications for Future Accelerators  

SciTech Connect (OSTI)

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.

Jay Benesch

2006-02-15T23:59:59.000Z

451

Slow wave structures using twisted waveguides for charged particle applications  

DOE Patents [OSTI]

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.

Kang, Yoon W.; Fathy, Aly E.; Wilson, Joshua L.

2012-12-11T23:59:59.000Z

452

Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams  

SciTech Connect (OSTI)

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.

Siemann, R.H.; /SLAC

2011-10-24T23:59:59.000Z

453

Acceleration Worksheet 8/24/2011 ACCELERATION WORKSHEET  

E-Print Network [OSTI]

Acceleration Worksheet 8/24/2011 ACCELERATION WORKSHEET College of Arts and Sciences Name _____________ TO _____________ month/year month/year II. I meet the requirements for acceleration under [fill out either a) or b;Acceleration Worksheet 8/24/2011 Acceleration 2011-2012 Courses of Study The faculty of the college desires

Davis, H. Floyd

454

acceleration linear collider: Topics by E-print Network  

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

breaking. Many extensions of the standard model have a decoupling limit, with a Higgs boson similar to the standard one and other, higher-mass states. Mindful of such...

455

2010 Annual Planning Summary for Stanford Linear Accelerator Center Site  

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 Delicious RankCombustionImprovement Awardflash2007-42attachment1.pdfmodule 4Department ofDepartment ofDepartmentOffice

456

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartment ofDepartment ofof EnergyYou areDowntown Site - MO 02 FUSRAP Considered005

457

GeV electrons due to a transition from laser wakefield acceleration to plasma wakefield acceleration  

E-Print Network [OSTI]

We show through experiments that a transition from laser wakefield acceleration (LWFA) regime to a plasma wakefield acceleration (PWFA) regime can drive electrons up to energies close to the GeV level. Initially, the acceleration mechanism is dominated by the bubble created by the laser in the nonlinear regime of LWFA, leading to an injection of a large number of electrons. After propagation beyond the depletion length, leading to a depletion of the laser pulse, whose transverse ponderomotive force is not able to sustain the bubble anymore, the high energy dense bunch of electrons propagating inside bubble will drive its own wakefield by a PWFA regime. This wakefield will be able to trap and accelerate a population of electrons up to the GeV level during this second stage. Three dimensional (3D) particle-in-cell (PIC) simulations support this analysis, and confirm the scenario.

P. E. Masson-Laborde; M. Z. Mo; A. Ali; S. Fourmaux; P. Lassonde; J. C. Kieffer; W. Rozmus; D. Teychenne; R. Fedosejevs

2014-08-06T23:59:59.000Z

458

Safety of Accelerator Facilities  

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

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.

2004-07-23T23:59:59.000Z

459

Safety of Accelerator Facilities  

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

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.

2001-01-08T23:59:59.000Z

460

Microscale acceleration history discriminators  

DOE Patents [OSTI]

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.

Polosky, Marc A. (Albuquerque, NM); Plummer, David W. (Albuquerque, NM)

2002-01-01T23:59:59.000Z

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


461

Neutrino physics at accelerators  

E-Print Network [OSTI]

Present and future neutrino experiments at accelerators are mainly concerned with understanding the neutrino oscillation phenomenon and its implications. Here a brief account of neutrino oscillations is given together with a description of the supporting data. Some current and planned accelerator neutrino experiments are also explained.

Enrique Fernandez

2006-07-16T23:59:59.000Z

462

Accelerators (5/5)  

ScienceCinema (OSTI)

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.

None

2011-10-06T23:59:59.000Z

463

Safety of Accelerator Facilities  

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

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. Cancels DOE O 420.2B.

2011-07-21T23:59:59.000Z

464

Accelerators (4/5)  

ScienceCinema (OSTI)

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.

None

2011-10-06T23:59:59.000Z

465

Accelerators (3/5)  

ScienceCinema (OSTI)

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.

None

2011-10-06T23:59:59.000Z

466

Accelerator Modeling with MATLAB Accelerator Toolbox  

SciTech Connect (OSTI)

This paper introduces Accelerator Toolbox (AT)--a collection of tools to model storage rings and beam transport lines in the MATLAB environment. The objective is to illustrate the flexibility and efficiency of the AT-MATLAB framework. The paper discusses three examples of problems that are analyzed frequently in connection with ring-based synchrotron light sources.

Terebilo, Andrei

2002-08-21T23:59:59.000Z

467

Radio Frequency Station - Beam Dynamics Interaction in Circular Accelerators  

SciTech Connect (OSTI)

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.

Mastoridis, Themistoklis; /Stanford U., Elect. Eng. Dept. /SLAC

2011-03-01T23:59:59.000Z

468

Accelerator Driven Nuclear Energy - The Thorium Option  

SciTech Connect (OSTI)

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.  

Rajendran Raja

2009-03-18T23:59:59.000Z

469

Accelerator Driven Nuclear Energy - The Thorium Option  

ScienceCinema (OSTI)

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.  

Rajendran Raja

2010-01-08T23:59:59.000Z

470

Particle beam and crabbing and deflecting structure  

DOE Patents [OSTI]

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.

Delayen, Jean (Yorktown, VA)

2011-02-08T23:59:59.000Z

471

Optically active biological particle distinguishing apparatus  

DOE Patents [OSTI]

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.

Salzman, Gary C. (Los Alamos, NM); Kupperman, Robert H. (Washington, DC)

1989-01-01T23:59:59.000Z

472

Particle separation  

DOE Patents [OSTI]

Embodiments of a method for selecting particles, such as based on their morphology, is disclosed. In a particular example, the particles are charged and acquire different amounts of charge, or have different charge distributions, based on their morphology. The particles are then sorted based on their flow properties. In a specific example, the particles are sorted using a differential mobility analyzer, which sorts particles, at least in part, based on their electrical mobility. Given a population of particles with similar electrical mobilities, the disclosed process can be used to sort particles based on the net charge carried by the particle, and thus, given the relationship between charge and morphology, separate the particles based on their morphology.

Moosmuller, Hans (Reno, NV); Chakrabarty, Rajan K. (Reno, NV); Arnott, W. Patrick (Reno, NV)

2011-04-26T23:59:59.000Z

473

DEDICATED HEAVY ION MEDICAL ACCELERATORS  

E-Print Network [OSTI]

Lancaster, R.B. Yourd, Pre~,Accelerator A w·ideroe~,Basedcarbon beam medical accelerator facility. N "' . ,;j "' ::lEat the MARIA Workshop III: Accelerator Systems for Relat ic

Gough, R.A.

2013-01-01T23:59:59.000Z

474

Accelerated Least Squares Multidimensional Scaling  

E-Print Network [OSTI]

x(make_x(36,2)) xACCELERATED SCALING R EFERENCES I.ACCELERATED LEAST SQUARES MULTIDIMENSIONAL SCALING JAN DEare simpler to write. ACCELERATED SCALING It is shown in De

Leeuw, Jan de

2006-01-01T23:59:59.000Z

475

Accelerated Least Squares Multidimensional Scaling  

E-Print Network [OSTI]

x(make_x(36,2)) xACCELERATED SCALING R EFERENCES I.ACCELERATED LEAST SQUARES MULTIDIMENSIONAL SCALING JAN DEare simpler to write. ACCELERATED SCALING It is shown in De

Jan de Leeuw

2011-01-01T23:59:59.000Z

476

Computational studies and optimization of wakefield accelerators  

E-Print Network [OSTI]

optimization of wakefield accelerators C. G. R. Geddes 1 ,from the U.S. -LHC Accelerator Research Program (LARP),driven plasma wakefield accelerators produce accelerating

Geddes, C.G.R.

2010-01-01T23:59:59.000Z

477

Measurements of the critical power for self-injection of electrons in a laser wakefield accelerator  

SciTech Connect (OSTI)

A laser wakefield acceleration study has been performed in the matched, self-guided, blow-out regime where a 10 J, 60 fs laser produced 720 {+-} 50 MeV quasi-monoenergetic electrons with a divergence of {Delta}{theta} = 2.85 {+-} 0.15 mRad. While maintaining a nearly constant plasma density (3 x 10{sup 18} cm{sup -3}), a linear electron energy gain was measured from 100 MeV to 700 MeV when the plasma length was scaled from 3 mm to 8 mm. Absolute charge measurements indicate that self-injection occurs when P/P{sub cr} > 4 and saturates around 100 pC for P/P{sub cr} > 12. The results are compared with both analytical scalings and full 3D particle-in-cell simulations.

Froula, D H; Clayton, C E; Doppner, T; Fonseca, R A; Marsh, K A; Barty, C J; Divol, L; Glenzer, S H; Joshi, C; Lu, W; Martins, S F; Michel, P; Mori, W; Palastro, J P; Pollock, B B; Pak, A; Ralph, J E; Ross, J S; Siders, C; Silva, L O; Wang, T

2009-06-02T23:59:59.000Z

478

Deuterium accelerator experiments for APT.  

SciTech Connect (OSTI)

Sandia National Laboratories in California initiated an experimental program to determine whether tritium retention in the tube walls and permeation through the tubes into the surrounding coolant water would be a problem for the Accelerator Production of Tritium (APT), and to find ways to mitigate the problem, if it existed. Significant holdup in the tube walls would limit the ability of APT to meet its production goals, and high levels of permeation would require a costly cleanup system for the cooling water. To simulate tritium implantation, a 200 keV accelerator was used to implant deuterium into Al 6061-T and SS3 16L samples at temperatures and particle fluxes appropriate for APT, for times varying between one week and five months. The implanted samples were characterized to determine the deuterium retention and Permeation. During the implantation, the D(d,p)T nuclear reaction was used to monitor the build-up of deuterium in the implant region of the samples. These experiments increased in sophistication, from mono-energetic deuteron implants to multi-energetic deuteron and proton implants, to more accurately reproduce the conditions expected in APT. Micron-thick copper, nickel, and anodized aluminum coatings were applied to the front surface of the samples (inside of the APT walls) in an attempt to lower retention and permeation. The reduction in both retention and permeation produced by the nickel coatings, and the ability to apply them to the inside of the APT tubes, indicate that both nickel-coated Al 6061-T6 and nickel-coated SS3 16L tubes would be effective for use in APT. The results of this work were submitted to the Accelerator Production of Tritium project in document number TPO-E29-Z-TNS-X-00050, APT-MP-01-17.

Causey, Rion A. (Sandia National Laboratories, Livermore, CA); Hertz, Kristin L. (Sandia National Laboratories, Livermore, CA); Cowgill, Donald F. (Sandia National Laboratories, Livermore, CA)

2005-08-01T23:59:59.000Z

479

Feasibility study of channeling acceleration experiment at the Fermilab ASTA facility  

E-Print Network [OSTI]

Crystal channeling technology has offered various opportunities in accelerator community with a viability of ultrahigh gradient (TV/m) acceleration for future HEP collider in Energy Frontier. The major challenge of the channeling acceleration is that ultimate acceleration gradients might require high power driver at hard x-ray regime (~ 40 keV), exceeding those conceivable for x-rays as of today, though x-ray lasers can efficiently excite solid plasma and accelerate particles inside a crystal channel. Moreover, only disposable crystal accelerators are possible at such high externally excited fields which would exceed the ionization thresholds destroying the atomic structure, so acceleration will take place only in a short time before full dissociation of the lattice. Carbon- based nanostructures have great potential with a wide range of flexibility and superior physical strength, which can be applied to channeling acceleration. This paper present beam-driven channeling acceleration concept with CNTs and discu...

Shin, Young-Min; Still, Dean A; Shiltsev, Vladimir

2015-01-01T23:59:59.000Z

480