FEL2015 - List of Authors (Brachmann, A.)

Paper	Title	Page
TUP070	Energy Jitter Minimization at LCLS	523
	L. Wang, A.L. Benwell, A. Brachmann, W.S. Colocho, F.-J. Decker, Z. Huang, T.J. Maxwell, T. Tao, J.L. Turner SLAC, Menlo Park, California, USA
	The energy jitters of the electron beam can affects the FEL in self-seeded modes if the jitter is large compared to the FEL parameter. We work in multiple ways to reduce the jitters, including hardware improvement, optimization linac set-up. This paper discusses the optimization of linac set-up. The solutions always suggest that we can largely reduce the energy jitter from a weak compression at BC1 and a stronger compression at BC2. Meanwhile a low beam energy at BC2 also reduce the energy jitter, which is confirmed by the experiment. The results can be explained by a simple model. Experimental results are also presented, demonstrating better than 20% and 40% relative energy jitter reduction for 13.6 and 4 GeV linac operation, respectively.
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TUP072	Cathode Ion Bombardment in LCLS and LCLS-II RF Gun	534
	L. Wang, A. Brachmann, F.-J. Decker, Z. Li, T.O. Raubenheimer, J.F. Schmerge, F. Zhou SLAC, Menlo Park, California, USA
	This paper studies the ions bombardment on the cathode in the LCLS and LCLS-II gun. APEX gun is used here for LCLS-II, which will be operate at 1 MHz repetition rate. Therefore, It is important to estimate the ion bombardment. One specific PIC code is used track arbitrary particles (ions and electron here) in arbitrary 2D/3D electromagnetic field and solenoid field to estimate the possibility of ion bombardment. The LCLS gun has 1.6 cells while the LCLS-II gun (APEX gun) is a half-cell gun. The frequencies of the two guns are also quite different. These characters make the ion dynamics quite differently. We estimated the bombardment for various ion species and studied the effects RF pulse shape and RF phase
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Paper

Title

Page

Energy Jitter Minimization at LCLS

523

L. Wang, A.L. Benwell, A. Brachmann, W.S. Colocho, F.-J. Decker, Z. Huang, T.J. Maxwell, T. Tao, J.L. Turner
SLAC, Menlo Park, California, USA

The energy jitters of the electron beam can affects the FEL in self-seeded modes if the jitter is large compared to the FEL parameter. We work in multiple ways to reduce the jitters, including hardware improvement, optimization linac set-up. This paper discusses the optimization of linac set-up. The solutions always suggest that we can largely reduce the energy jitter from a weak compression at BC1 and a stronger compression at BC2. Meanwhile a low beam energy at BC2 also reduce the energy jitter, which is confirmed by the experiment. The results can be explained by a simple model. Experimental results are also presented, demonstrating better than 20% and 40% relative energy jitter reduction for 13.6 and 4 GeV linac operation, respectively.

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUP072

Cathode Ion Bombardment in LCLS and LCLS-II RF Gun

534

L. Wang, A. Brachmann, F.-J. Decker, Z. Li, T.O. Raubenheimer, J.F. Schmerge, F. Zhou
SLAC, Menlo Park, California, USA

This paper studies the ions bombardment on the cathode in the LCLS and LCLS-II gun. APEX gun is used here for LCLS-II, which will be operate at 1 MHz repetition rate. Therefore, It is important to estimate the ion bombardment. One specific PIC code is used track arbitrary particles (ions and electron here) in arbitrary 2D/3D electromagnetic field and solenoid field to estimate the possibility of ion bombardment. The LCLS gun has 1.6 cells while the LCLS-II gun (APEX gun) is a half-cell gun. The frequencies of the two guns are also quite different. These characters make the ion dynamics quite differently. We estimated the bombardment for various ion species and studied the effects RF pulse shape and RF phase

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)