2011 Particle Accelerator Conference - List of Keywords (beam-transport)

Paper	Title	Other Keywords	Page
MOOCS5	Space-charge Effects in H⁻ Low-energy Beam Transport of LANSCE	emittance, space-charge, simulation, vacuum	64
	Y.K. Batygin, C. Pillai, L. Rybarcyk LANL, Los Alamos, New Mexico, USA
	The 750-keV low-energy beam transport of the Los Alamos Neutron Science Center (LANSCE) linac consists of two independent beam lines for simultaneous injection of H⁺ and H⁻ beams into the linear accelerator. While transport of the H⁺ beam is seriously affected by uncompensated space charge forces, the same effect for H⁻ is hidden by presence of multiple beam collimators and beam chopping. Recent results from beam development experiments indicate a significant influence of space charge on H⁻ beam dynamics in the low-energy beam transport. Measurements of beam emittance along beam transport show the formation of S-shaped filamentation in the particle distribution phase space, typical with the presence of non-linear space charge forces. Results are supported by particle tracking simulations with the PARMILA, BEAMPATH, and TRACE codes.
	Slides MOOCS5 [6.304 MB]

TUP208	DESIGNING A BEAM TRANSPORT SYSTEM FOR RHIC’S ELECTRON LENS	electron, solenoid, dipole, controls	1205
	X. Gu, W. Fischer, R.C. Gupta, J. Hock, Y. Luo, M. Okamura, A.I. Pikin, D. Raparia BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. We designed two electron lenses to apply head-on beam-beam compensation for RHIC; they will be installed near IP10. The electron-beam transport system is an important subsystem of the entire electron-lens system. Electrons are transported from the electron gun to the main solenoid and further to the collector. The system must allow for changes of the electron beam size inside the superconducting magnet, and for changes of the electron position by 5 mm in the horizontal- and vertical-planes.

WEP032	Beam Transport in a Compact Dielectric Wall Accelerator for Proton Therapy	proton, accelerating-gradient, emittance, focusing	1552
	Y.-J. Chen, D.T. Blackfield, G.J. Caporaso, S.D. Nelson, B. R. Poole LLNL, Livermore, California, USA
	Funding: This work performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA2A27344. To attain the highest accelerating gradient in the compact dielectric wall (DWA) accelerator, the accelerating voltage pulses should have the shortest possible duration. To do so, the DWA will be operated in the “virtual” traveling mode. Since only a short section of HGI wall would be excited, the accelerating field’s axial profile could be non-uniform and time dependent, especially near the entrance and exit of the DWA, which could lead to dispersion in beam acceleration and transport, and eventually emittance growth. The dispersive transverse kick on a short proton bunch at the DWA entrance and its impact on acceptable input proton bunch length will be discussed. Without using any external lenses, the dispersive transverse kicks on the beam can be mitigated. Implementing the mitigations into the transport strategy, we have established a baseline transport case. Results of simulations using 3-D, EM PIC code, LSP* indicate that the DWA transport performance meets the medical specifications for intensity modulation proton treatment. Sensitivity of the transport performance to the switch timing will be presented. * G. J. Caporaso, Y-J Chen and S. E. Sampayan, "The Dielectric Wall Accelerator", Rev. of Accelerator Science and Technology, vol. 2, p. 253 (2009). ** Alliant Techsystems Inc., http://www.lspsuite.com/.

WEP038	Physics Design of a Prototype 2-Solenoid LEBT for the SNS Injector	solenoid, rfq, ion, simulation	1564
	B. Han, D.J. Newland ORNL RAD, Oak Ridge, Tennessee, USA T. Hunter, M.P. Stockli ORNL, Oak Ridge, Tennessee, USA
	To mitigate the operational risks associated with the SNS electrostatic LEBT, an R&D effort is underway to develop a 2-solenoid magnetic LEBT, which should improve the reliability while matching or exceeding the beam dynamic capabilities of the present electrostatic LEBT. This paper discusses the physics design of a prototype 2-solenoid magnetic LEBT.

WEP101	Smooth Approximation of Dispersion with Strong Space Charge	space-charge, emittance, heavy-ion, focusing	1665
	S. Bernal, B.L. Beaudoin, T.W. Koeth, P.G. O'Shea UMD, College Park, Maryland, USA
	Funding: This work is funded by the US Dept. of Energy Offices of High Energy Physics and High Energy Density Physics, and by the US Dept. of Defense Office of Naval Research and Joint Technology Office. We apply the Venturini-Reiser envelope-dispersion equations* to a continuous beam in a uniform focusing/bending lattice to study the combined effects of linear dispersion and space charge. Within this simple model we investigate the scaling of average dispersion and the effects on beam dimensions; we also introduce a generalization of the space-charge intensity parameter and apply it to the University of Maryland Electron Ring (UMER) and other machines. In addition, we present results of calculations to test the smooth approximation by solving the Venturini-Reiser original equations and also through simulations with the code ELEGANT. *M. Venturini and M. Reiser, Phys. Rev. Lett. 81, 1, p. 96, 6 July 1998

Paper

Title

Other Keywords

Page

MOOCS5

Space-charge Effects in H⁻ Low-energy Beam Transport of LANSCE

emittance, space-charge, simulation, vacuum

64

Y.K. Batygin, C. Pillai, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

The 750-keV low-energy beam transport of the Los Alamos Neutron Science Center (LANSCE) linac consists of two independent beam lines for simultaneous injection of H⁺ and H⁻ beams into the linear accelerator. While transport of the H⁺ beam is seriously affected by uncompensated space charge forces, the same effect for H⁻ is hidden by presence of multiple beam collimators and beam chopping. Recent results from beam development experiments indicate a significant influence of space charge on H⁻ beam dynamics in the low-energy beam transport. Measurements of beam emittance along beam transport show the formation of S-shaped filamentation in the particle distribution phase space, typical with the presence of non-linear space charge forces. Results are supported by particle tracking simulations with the PARMILA, BEAMPATH, and TRACE codes.

Slides MOOCS5 [6.304 MB]

TUP208

DESIGNING A BEAM TRANSPORT SYSTEM FOR RHIC’S ELECTRON LENS

electron, solenoid, dipole, controls

1205

X. Gu, W. Fischer, R.C. Gupta, J. Hock, Y. Luo, M. Okamura, A.I. Pikin, D. Raparia
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
We designed two electron lenses to apply head-on beam-beam compensation for RHIC; they will be installed near IP10. The electron-beam transport system is an important subsystem of the entire electron-lens system. Electrons are transported from the electron gun to the main solenoid and further to the collector. The system must allow for changes of the electron beam size inside the superconducting magnet, and for changes of the electron position by 5 mm in the horizontal- and vertical-planes.

WEP032

Beam Transport in a Compact Dielectric Wall Accelerator for Proton Therapy

proton, accelerating-gradient, emittance, focusing

1552

Y.-J. Chen, D.T. Blackfield, G.J. Caporaso, S.D. Nelson, B. R. Poole
LLNL, Livermore, California, USA

Funding: This work performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA2A27344.
To attain the highest accelerating gradient in the compact dielectric wall (DWA) accelerator, the accelerating voltage pulses should have the shortest possible duration. To do so, the DWA will be operated in the “virtual” traveling mode*. Since only a short section of HGI wall would be excited, the accelerating field’s axial profile could be non-uniform and time dependent, especially near the entrance and exit of the DWA, which could lead to dispersion in beam acceleration and transport, and eventually emittance growth. The dispersive transverse kick on a short proton bunch at the DWA entrance and its impact on acceptable input proton bunch length will be discussed. Without using any external lenses, the dispersive transverse kicks on the beam can be mitigated. Implementing the mitigations into the transport strategy, we have established a baseline transport case. Results of simulations using 3-D, EM PIC code, LSP** indicate that the DWA transport performance meets the medical specifications for intensity modulation proton treatment. Sensitivity of the transport performance to the switch timing will be presented.
* G. J. Caporaso, Y-J Chen and S. E. Sampayan, "The Dielectric Wall Accelerator", Rev. of Accelerator Science and Technology, vol. 2, p. 253 (2009).
** Alliant Techsystems Inc., http://www.lspsuite.com/.

WEP038

Physics Design of a Prototype 2-Solenoid LEBT for the SNS Injector

solenoid, rfq, ion, simulation

1564

B. Han, D.J. Newland
ORNL RAD, Oak Ridge, Tennessee, USA
T. Hunter, M.P. Stockli
ORNL, Oak Ridge, Tennessee, USA

To mitigate the operational risks associated with the SNS electrostatic LEBT, an R&D effort is underway to develop a 2-solenoid magnetic LEBT, which should improve the reliability while matching or exceeding the beam dynamic capabilities of the present electrostatic LEBT. This paper discusses the physics design of a prototype 2-solenoid magnetic LEBT.

WEP101

Smooth Approximation of Dispersion with Strong Space Charge

space-charge, emittance, heavy-ion, focusing

1665

S. Bernal, B.L. Beaudoin, T.W. Koeth, P.G. O'Shea
UMD, College Park, Maryland, USA

Funding: This work is funded by the US Dept. of Energy Offices of High Energy Physics and High Energy Density Physics, and by the US Dept. of Defense Office of Naval Research and Joint Technology Office.
We apply the Venturini-Reiser envelope-dispersion equations* to a continuous beam in a uniform focusing/bending lattice to study the combined effects of linear dispersion and space charge. Within this simple model we investigate the scaling of average dispersion and the effects on beam dimensions; we also introduce a generalization of the space-charge intensity parameter and apply it to the University of Maryland Electron Ring (UMER) and other machines. In addition, we present results of calculations to test the smooth approximation by solving the Venturini-Reiser original equations and also through simulations with the code ELEGANT.
*M. Venturini and M. Reiser, Phys. Rev. Lett. 81, 1, p. 96, 6 July 1998