ICAP2012 - List of Keywords (focusing)

Paper	Title	Other Keywords	Page
WEP15	Tools for Analysis and Improvement of Linac Optics Design for High Brightness Electron Beams	optics, quadrupole, controls, emittance	170
	S. Di Mitri, M. Cornacchia, C. Scafuri ELETTRA, Basovizza, Italy
	The optics design of single pass high brightness electron linacs usually aims at the preservation of the transverse emittance. Collective effects mainly impose constraints to the optics design such as at the low-beta interaction points in colliders and magnetic compressors in FELs. Other constraints are from the trajectory correction scheme, performance of diagnostics, collimation systems and physical space limitations. Strong focusing is typically prescribed for all the aforementioned cases, although it may hamper the main goal of emittance preservation through the excitation of optical aberrations. Strong focusing also potentially leads, through focusing errors, to large beam optics mismatch. Based on these sometimes conflicting requirements, we have developed tools for the analysis and improvement of electron linac optics. They are based on the Elegant [1] code and allow the user to identify: local sources of phase space distortions and emittance dilution, lattice areas particularly sensitive to focusing errors, poor trajectory steering. The analysis does not require massive particle tracking since it deals with the single particle motion in the normalized phase space. [1] M. Borland, Advanced Photon Source LS-287 (2000).

WEP16	Analytical Presentation of Space Charge Forces	space-charge, controls, beam-transport, optics	173
	S.N. Andrianov St. Petersburg State University, St. Petersburg, Russia
	Funding: The work is supported by Federal Targeted Programme "Scientific and Scientific-Pedagogical Personnel of the Innovative Russia in 2009-2013" (Governmental Contract no. p 793) This paper presents an analytical description of the space charge forces generated by charged particle beams. The suggested approach is based on some set of models for particle distribution function. All necessary calculations have analytical and closed form for different models for beam density distributions. These model distributions can be used for approximation of real beam distributions. The corresponding solutions are included in a general scheme of beam dynamics presentation based on the matrix formalism for Lie algebraic tools. The corresponding computer software is based on corresponding symbolic codes and some parallel technologies. In particular, as computational tools we consider GPU graphic card NVIDIA. As an example, there is considered the problem of modeling the beam dynamics for microprobe focusing systems.

WEACC2	Space Charge Effects and Focusing Methods for Laser Accelerated Ion Beams	space-charge, solenoid, simulation, laser	184
	P. Schmidt, O. Boine-Frankenheim, V. Kornilov, P. Spädtke GSI, Darmstadt, Germany
	Funding: GSI Helmholtzzentrum für Schwerionenforschung Planckstr. 1 D-64291 Darmstadt We employ the 3D PIC simulation code VORPAL to study the transport of laser accelerated proton beams in the framework of the LIGHT project at GSI. Initially the beam is assumed to be neutralized by co-moving electrons. For different initial beam distribution models we study the effect of space charge after the electrons have been removed. The results of the simulations are compared to an envelope model. We derive conditions in terms of the beam parameters and the distance from the production target for a safe removal of the electrons. As an option for the controlled de-neutralization of the beam a thin metallic foil is studied. Besides space charge, we also account for the effect of secondary electrons generated from the foil.
	Slides WEACC2 [0.993 MB]

THP08	Beam Dynamics Studies for Particle Driven Plasma Wakefield Acceleration Experiments at PITZ	plasma, electron, simulation, laser	236
	M. Khojoyan, M. Groß, G. Klemz, G. Koss, M. Krasilnikov, A. Oppelt, F. Stephan DESY Zeuthen, Zeuthen, Germany M. Khojoyan ANSL, Yerevan, Armenia
	The Photo Injector Test Facility at DESY, Zeuthen site (PITZ) is developing and optimizing high brightness electron sources for linac based free electron lasers such as FLASH and the European XFEL. The high quality of the 25 MeV electron beam together with the availability of a highly flexible photocathode laser system makes the PITZ injector a perfect facility for variety of experimental studies. Two approaches are of great interest for future applications in the context of particle driven plasma wakefield acceleration experiments: self-modulation and transformer ratio studies. In both cases a high density electron beam is interacting with a plasma which has a density of about 10¹⁵ cm^-3. ASTRA simulations were done to study the e-beam density along the existing PITZ beamline, especially at two different possible longitudinal positions of the planned plasma cell, in order to reach the particle density required for occurrence of self-modulation. The results of the beam dynamics studies are presented and discussed in this paper.

Paper

Title

Other Keywords

Page

WEP15

Tools for Analysis and Improvement of Linac Optics Design for High Brightness Electron Beams

optics, quadrupole, controls, emittance

170

S. Di Mitri, M. Cornacchia, C. Scafuri
ELETTRA, Basovizza, Italy

The optics design of single pass high brightness electron linacs usually aims at the preservation of the transverse emittance. Collective effects mainly impose constraints to the optics design such as at the low-beta interaction points in colliders and magnetic compressors in FELs. Other constraints are from the trajectory correction scheme, performance of diagnostics, collimation systems and physical space limitations. Strong focusing is typically prescribed for all the aforementioned cases, although it may hamper the main goal of emittance preservation through the excitation of optical aberrations. Strong focusing also potentially leads, through focusing errors, to large beam optics mismatch. Based on these sometimes conflicting requirements, we have developed tools for the analysis and improvement of electron linac optics. They are based on the Elegant [1] code and allow the user to identify:

local sources of phase space distortions and emittance dilution,
lattice areas particularly sensitive to focusing errors,
poor trajectory steering.

The analysis does not require massive particle tracking since it deals with the single particle motion in the normalized phase space.
[1] M. Borland, Advanced Photon Source LS-287 (2000).

WEP16

Analytical Presentation of Space Charge Forces

space-charge, controls, beam-transport, optics

173

S.N. Andrianov
St. Petersburg State University, St. Petersburg, Russia

Funding: The work is supported by Federal Targeted Programme "Scientific and Scientific-Pedagogical Personnel of the Innovative Russia in 2009-2013" (Governmental Contract no. p 793)
This paper presents an analytical description of the space charge forces generated by charged particle beams. The suggested approach is based on some set of models for particle distribution function. All necessary calculations have analytical and closed form for different models for beam density distributions. These model distributions can be used for approximation of real beam distributions. The corresponding solutions are included in a general scheme of beam dynamics presentation based on the matrix formalism for Lie algebraic tools. The corresponding computer software is based on corresponding symbolic codes and some parallel technologies. In particular, as computational tools we consider GPU graphic card NVIDIA. As an example, there is considered the problem of modeling the beam dynamics for microprobe focusing systems.

WEACC2

Space Charge Effects and Focusing Methods for Laser Accelerated Ion Beams

space-charge, solenoid, simulation, laser

184

P. Schmidt, O. Boine-Frankenheim, V. Kornilov, P. Spädtke
GSI, Darmstadt, Germany

Funding: GSI Helmholtzzentrum für Schwerionenforschung Planckstr. 1 D-64291 Darmstadt
We employ the 3D PIC simulation code VORPAL to study the transport of laser accelerated proton beams in the framework of the LIGHT project at GSI. Initially the beam is assumed to be neutralized by co-moving electrons. For different initial beam distribution models we study the effect of space charge after the electrons have been removed. The results of the simulations are compared to an envelope model. We derive conditions in terms of the beam parameters and the distance from the production target for a safe removal of the electrons. As an option for the controlled de-neutralization of the beam a thin metallic foil is studied. Besides space charge, we also account for the effect of secondary electrons generated from the foil.

Slides WEACC2 [0.993 MB]

THP08

Beam Dynamics Studies for Particle Driven Plasma Wakefield Acceleration Experiments at PITZ

plasma, electron, simulation, laser

236

M. Khojoyan, M. Groß, G. Klemz, G. Koss, M. Krasilnikov, A. Oppelt, F. Stephan
DESY Zeuthen, Zeuthen, Germany
M. Khojoyan
ANSL, Yerevan, Armenia

The Photo Injector Test Facility at DESY, Zeuthen site (PITZ) is developing and optimizing high brightness electron sources for linac based free electron lasers such as FLASH and the European XFEL. The high quality of the 25 MeV electron beam together with the availability of a highly flexible photocathode laser system makes the PITZ injector a perfect facility for variety of experimental studies. Two approaches are of great interest for future applications in the context of particle driven plasma wakefield acceleration experiments: self-modulation and transformer ratio studies. In both cases a high density electron beam is interacting with a plasma which has a density of about 10¹⁵ cm^-3. ASTRA simulations were done to study the e-beam density along the existing PITZ beamline, especially at two different possible longitudinal positions of the planned plasma cell, in order to reach the particle density required for occurrence of self-modulation. The results of the beam dynamics studies are presented and discussed in this paper.