PAC07 - List of Authors (Cary, J. R.)

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Cary, J. R.

Paper	Title	Page
WEYKI02	Experimental Demonstration of 1 GeV Energy Gain in a Laser Wakefield Accelerator	1911
	A. J. Gonsalves, S. M. Hooker OXFORDphysics, Oxford, Oxon D. L. Bruhwiler, J. R. Cary Tech-X, Boulder, Colorado E. Cormier-Michel University of Nevada, Reno, Reno, Nevada E. Esarey, C. G.R. Geddes, W. Leemans, K. Nakamura, C. B. Schroeder, C. Toth LBNL, Berkeley, California
	GeV-class electron accelerators have a broad range of uses, including synchrotron facilities, free electron lasers, and high-energy particle physics. The accelerating gradient achievable with conventional radio frequency (RF) accelerators is limited by electrical breakdown within the accelerating cavity to a few tens of MeV, so the production of energetic beams requires large, expensive accelerators. One promising technology to reduce the cost and size of these accelerators (and to push the energy frontier for high-energy physics) is the laser-wakefield accelerator (LWFA), since these devices can sustain electric fields of hundreds of GV/m. In this talk, results will be presented on the first demonstration of GeV-class beams using an intense laser beam. Laser pulses with peak power ranging from 10-40TW were guided in a 3.3 cm long gas-filled capillary discharge waveguide, allowing the production of high-quality electron beams with energy up to 1 GeV. The electron beam characteristics and laser guiding, and their dependence on laser and plasma parameters will be discussed and compared to simulations.
	Slides
WEOBKI01	Stable Electron Beams with Low Absolute Energy Spread from a Laser Wakefield Accelerator with Plasma Density Ramp Controlled Injection	1916
	C. G.R. Geddes, E. Esarey, W. Leemans, K. Nakamura, D. Panasenko, G. R.D. Plateau, C. B. Schroeder, C. Toth LBNL, Berkeley, California J. R. Cary Tech-X, Boulder, Colorado E. Cormier-Michel University of Nevada, Reno, Reno, Nevada
	Funding: Supported by DOE, including grant DE-AC02-05CH11231, DARPA, and by an INCITE computational award. Laser wakefield accelerators produce accelerating gradients up to hundreds of GeV/m and narrow energy spread, and have recently demonstrated energies up to GeV and improved stability [,] using electrons self trapped from the plasma. Controlled injection and staging can further improve beam quality by circumventing tradeoffs between energy, stability, and energy spread/emittance. We present experiments demonstrating production of a stable electron beam near 1 MeV with 100 keV level energy spread and central energy stability by using the plasma density profile to control self injection, and supporting simulations. A 10 TW laser pulse was focused near the downstream edge of a mm-long hydrogen gas jet. The plasma density near focus is decreasing in the laser propagation direction, which changes the wake phase velocity and reduces the trapping threshold. This allows stable self trapping and low absolute energy spread. Simulations indicate that such beams can be post accelerated to form high energy, high quality, stable beams, and experiments are under investigation. Geddes et al, Nature v431 no7008, 538 (2004).** Leemans et al, Nature Physics v2 no10, p696 (2006)
	Slides
THPMN112	Colliding Pulse Injection Experiments in Non-Collinear Geometry for Controlled Laser Plasma Wakefield Acceleration of Electrons	2975
	C. Toth, E. Esarey, C. G.R. Geddes, W. Leemans, K. Nakamura, D. Panasenko, C. B. Schroeder LBNL, Berkeley, California D. L. Bruhwiler, J. R. Cary Tech-X, Boulder, Colorado
	Funding: Supported by DOE grant DE-AC02-05CH11231, DARPA, and and INCITE computational grant. Colliding laser pulses* have been proposed as a method for controlling injection of electrons into a laser wakefield accelerator (LWFA) and hence producing high quality relativistic electron beams with energy spread below 1% and normalized emittances below 1 micron. The original proposal relied on three coaxial pulsesI. One pulse excites a plasma wake, and a collinear pulse following behind it collides with a counterpropagating pulse forming a beat pattern that boosts background electrons into accelerating phase. A variation of this method uses only two laser pulses** which may be non-collinear. The first pulse drives the wake, and beating of the trailing edge of this pulse with the colliding pulse injects electrons. Non-collinear injection avoids optical elements on the electron beam path (avoiding emittance growth). We report on progress of non-collinear experiments at LBNL, using the Ti:Sapphire laser at the LOASIS facility of LBNL. Preliminary results indicate that electron beam properties are affected by the second beam. Details of the experiment will be presented. * E. Esarey, et al, Phys. Rev. Lett 79, 2682 (1997).** G. Fubiani, Phys. Rev. E 70, 016402 (2004).
WEOCKI03	Status of the R&D Towards Electron Cooling of RHIC	1938
	I. Ben-Zvi, J. Alduino, D. S. Barton, D. Beavis, M. Blaskiewicz, J. M. Brennan, A. Burrill, R. Calaga, P. Cameron, X. Chang, K. A. Drees, A. V. Fedotov, W. Fischer, G. Ganetis, D. M. Gassner, J. G. Grimes, H. Hahn, L. R. Hammons, A. Hershcovitch, H.-C. Hseuh, D. Kayran, J. Kewisch, R. F. Lambiase, D. L. Lederle, V. Litvinenko, C. Longo, W. W. MacKay, G. J. Mahler, G. T. McIntyre, W. Meng, B. Oerter, C. Pai, G. Parzen, D. Pate, D. Phillips, S. R. Plate, E. Pozdeyev, T. Rao, J. Reich, T. Roser, A. G. Ruggiero, T. Russo, C. Schultheiss, Z. Segalov, J. Smedley, K. Smith, T. Tallerico, S. Tepikian, R. Than, R. J. Todd, D. Trbojevic, J. E. Tuozzolo, P. Wanderer, G. Wang, D. Weiss, Q. Wu, K. Yip, A. Zaltsman BNL, Upton, Long Island, New York D. T. Abell, G. I. Bell, D. L. Bruhwiler, R. Busby, J. R. Cary, D. A. Dimitrov, P. Messmer, V. H. Ranjbar, D. S. Smithe, A. V. Sobol, P. Stoltz Tech-X, Boulder, Colorado A. V. Aleksandrov, D. L. Douglas, Y. W. Kang ORNL, Oak Ridge, Tennessee H. Bluem, M. D. Cole, A. J. Favale, D. Holmes, J. Rathke, T. Schultheiss, J. J. Sredniawski, A. M.M. Todd AES, Princeton, New Jersey A. V. Burov, S. Nagaitsev, L. R. Prost Fermilab, Batavia, Illinois Y. S. Derbenev, P. Kneisel, J. Mammosser, H. L. Phillips, J. P. Preble, C. E. Reece, R. A. Rimmer, J. Saunders, M. Stirbet, H. Wang Jefferson Lab, Newport News, Virginia V. V. Parkhomchuk, V. B. Reva BINP SB RAS, Novosibirsk A. O. Sidorin, A. V. Smirnov JINR, Dubna, Moscow Region
	Funding: Work done under the auspices of the US DOE with support from the US DOD. The physics interest in a luminosity upgrade of RHIC requires the development of a cooling-frontier facility. Detailed cooling calculations have been made to determine the efficacy of electron cooling of the stored RHIC beams. This has been followed by beam dynamics simulations to establish the feasibility of creating the necessary electron beam. Electron cooling of RHIC at collisions requires electron beam energy up to about 54 MeV at an average current of between 50 to 100 mA and a particularly bright electron beam. The accelerator chosen to generate this electron beam is a superconducting Energy Recovery Linac (ERL) with a superconducting RF gun with a laser-photocathode. An intensive experimental R&D program engages the various elements of the accelerator: Photocathodes of novel design, superconducting RF electron gun of a particularly high current and low emittance, a very high-current ERL cavity and a demonstration ERL using these components.
	Slides
THPAS008	Simulation of the Dynamics of Microwave Transmission Through an Electron Cloud	3525
	K. G. Sonnad, M. A. Furman LBNL, Berkeley, California J. R. Cary CIPS, Boulder, Colorado P. Stoltz, S. A. Veitzer Tech-X, Boulder, Colorado
	Funding: Work supported by the U. S. DOE under Contract no. DE-AC02-05CH11231 Simulation studies are under way to analyze the dynamics of microwave transmission through a beam channel containing electron clouds. Such an interaction is expected to produce a shift in phase accompanied by attenuation in the amplitude of the microwave radiation. Experimental observation of these phenomena would lead to a useful diagnosis tool for electron clouds. This technique has already been studied* at the CERN SPS. Similar experiments are being proposed at the PEP-II LER at SLAC as well as the Fermilab MI. In this study, simulation results will be presented for a number of cases including those representative of the above mentioned experiments. The code VORPAL is being utilized to perform electromagnetic particle-in-cell (PIC) calculations. The results are expected to provide guidance to the above mentioned experiments as well as lead to a better understanding of the problem. * T. Kroyer, F. Caspers, E. Mahner , pg 2212 Proc. PAC 2005, Knoxville, TN
THPAS020	3D Simulations of Secondary Electron Generation and Transport in a Diamond Amplifier for Photocathodes	3555
	D. A. Dimitrov, D. L. Bruhwiler, R. Busby, J. R. Cary Tech-X, Boulder, Colorado I. Ben-Zvi, X. Chang, T. Rao, J. Smedley, Q. Wu BNL, Upton, Long Island, New York
	The Relativistic Heavy Ion Collider (RHIC) contributes fundamental advances to nuclear physics by colliding a wide range of ions. A novel electron cooling section, which is a key component of the proposed luminosity upgrade for RHIC, requires the acceleration of high-charge electron bunches with low emittance and energy spread. A promising candidate for the electron source is the recently developed concept of a high quantum efficiency photoinjector with a diamond amplifier. We have started to implement algorithms, within the VORPAL particle-in-cell framework, for modeling of secondary electron and hole generation, and for charge transport in diamond. The algorithms include elastic and various inelastic scattering processes over a wide range of charge carrier energies. Initial results from the implemented capabilities will be presented and discussed. The work at Tech-X Corp. is supported by the U. S. Department of Energy under a Phase I SBIR grant.