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ICFA Advanced Accelerator Workshop on the Physics of High Brightness Beams 2nd

Name: ICFA Advanced Accelerator Workshop on the Physics of High Brightness Beams 2nd

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Date: 2000-04-01

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Created at: Fri Jul 27 23:53:35 -0700 2007

Updated at: Fri Sep 02 13:12:42 -0700 2016

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6 papers from the conference:

title: Limitations on the resolution of YAG:Ce beam profile monitor for high brightness electron beam
format: conference proceeding
conference: ICFA Advanced Accelerator Workshop on the Physics of High Brightness Beams 2nd
year: 2000
5 authors: A. Murokh | V. Yakimenko | E. Johnson | X.J. Wang | J.B. Rosenzweig
abstract: The performance of single crystal YAG:Ce (Y_(3)Al_(5)O_(12)) beam profile monitors was studied for transverse masurements on the high brightness ultrarelativistic electron beam at Accelerator Test Facility (ATF) at BNL. The test demonstrated systematic intensity dependent beam enlargement on YAG monitors, compared to other diagnostics. Possible mechanisms of the effect have been studied. The quantitative examination was performed and compared to the developed phenomenological models. Limitations on the use of YAG:Ce diagnostics are discussed with respect to the high-brightness electron sources.
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title: HOMDYN study for the LCLS RF photo-injector
format: conference proceeding
conference: ICFA Advanced Accelerator Workshop on the Physics of High Brightness Beams 2nd
year: 2000
5 authors: M. Ferrario | Clendenin, J. E. | D. T. Palmer | J.B. Rosenzweig | L. Serafini
abstract: We report the results of a recent beam dynamics study, motivated by the need to redesign the LCLS photoinjector, that led to the discovery of a new effective working point for a split RF photoinjector. The HOMDYN code, the main simulation tool adopted in this work, is described together with its recent improvements. The new working point and its LCLS application is discussed. Validation tests of the HOMDYN model and low emittance predictions, 0.3 mm-mrad for a 1 nC flat top bunch, are performed with respect to the multi-particle tracking codes ITACA and PARMELA. (26 References).
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title: Single crystal copper photo-cathode in the BNL/SLAC/UCLA 1.6 cell RF gun
format: conference proceeding
conference: ICFA Advanced Accelerator Workshop on the Physics of High Brightness Beams 2nd
year: 2000
3 authors: D. T. Palmer | S. Anderson | J.B. Rosenzweig
abstract: Previous experimental measurements in the two dimensional (2D) variation of the quantum efficiency, QE, of a polycrystalline copper photo-cathode have measured a 25% variation in this quantity. Two possible causes of this 2D QE variation are contamination of the photo-emitting surface and the work function variation of copper due to crystal facet orientation. We report on the progress to eliminate the 2D QE variation due to the non-uniform crystal facet orientation of copper photo-emitters. This is accomplished by replacing the polycrystalline photo-emitter region of the cathode plane in a modified version of the BNL/SLAC/UCLA 1.6 cell rf gun with a thin disk of a single crystal copper Cu_100. In this paper we present a theoretical discussion on the effect that the crystal structure orientation of a photo-emitter has on the 2D QE. The manufacturing process used in the construction of the single crystal Cu_100 photo-cathode used in these photo-emission experiments are discussed. Preliminary experimental results are presented along with a discussion of our future experimental plans.
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title: Plasma electron trapping and acceleration in a plasma wake field using a density transition
format: conference proceeding
conference: ICFA Advanced Accelerator Workshop on the Physics of High Brightness Beams 2nd
year: 2000
4 authors: Suk, H. | N. Barov | J.B. Rosenzweig | E. Esarey
abstract: A new scheme for plasma electron injection into an acceleration phase of a plasma wake field is presented. In this scheme, a short single electron beam bunch is sent through an underdense plasma with a sharp downward density transition and some plasma electrons are trapped in the plasma wake field due to the rapid wavelength increase of the wake wave at the density transition. To investigate the trapping and acceleration mechanism, two-dimensional particle-in-cell (PIC) simulations were performed, and the illustrative 2-D simulation shows that the new injection method can produce a relatively large charge (~0.5 nC), short (~1 ps) and high energy (> driving beam energy) electron beam pulse with a plasma density transition from 5x10(13) cm(-3) to 3.5x10(13) cm(-3). In addition to the 2-D simulations, 1-D analytic work based on the Hamiltonian formalism and 1D simulations have been performed and the results are also presented. Finally, a proposed experiment at the Neptune Laboratory of UCLA is described.
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title: Characterizing The Electron Beam For The Aps Leutl Free Electron Laser
format: conference proceeding
conference: ICFA Advanced Accelerator Workshop on the Physics of High Brightness Beams 2nd
year: 2000
3 authors: G. Travish | J. W. Lewellen | M. W. Hahne
abstract: The Advanced Photon Source (APS) Low-Energy Undulator Test Line (LEUTL) project was originally intended to test and characterize advanced undulator designs via electron beambased diagnostics technique. It is presently being used to conduct free electron laser (FEL) research for a future fourth-generation light source. The APS injector linac has been upgraded to deliver a beam suitable for these FEL tests. The project has as an initial goal the operation of a self amplified spontaneous emission (SASE) device operating in the visible at 530 nm (green light). The visible FEL requires a 217 MeV moderately high brightness beam with a peak current of 100 A or greater, a normalized rms emittance of 5 ?m or less, and an energy spread of 0.1% or better. Beam characterization is fundamental to being able to match experimental results with theoretical models. This paper describes the LEUTL FEL, lists the major goals, the beam diagnostics, and presents the initial electron beam measured properties. Future plans are also discussed.
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title: Nonequilibrium transverse motion and emittance growth in space-charge dominated beams
format: conference proceeding
conference: ICFA Advanced Accelerator Workshop on the Physics of High Brightness Beams 2nd
year: 2000
2 authors: S. Anderson | J.B. Rosenzweig
abstract: The transverse dynamics of space-charge dominated beams are investigated both analytically and computationally, in order to understand the mechanisms for emittance oscillations and growth due to nonlinear space-charge fields. This work explores the role of space-charge dominated equilibrium and its relationship to phase space wave-breaking, which is responsible for the irreversible emittance growth in these systems. The physics of both coasting and accelerating beams are examined, in order to illuminate the most effective approaches to beam handling during the emittance compensation process, as well as during subsequent beam transport. (13 References).
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