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Title: Start-to-end simulation of the shot-noise driven microbunching instability experiment at the Linac Coherent Light Source

Abstract

The shot-noise driven microbunching instability can significantly degrade electron beam quality in x-ray free electron laser light sources. Experiments were carried out at the Linac Coherent Light Source (LCLS) to study this instability. Here in this paper, we present start-to-end simulations of the shot-noise driven microbunching instability experiment at the LCLS using the real number of electrons. The simulation results reproduce the measurements quite well. A microbunching self-heating mechanism is also illustrated in the simulation, which helps explain the experimental observation.

Authors:
 [1];  [2];  [2];  [2];  [2];  [2];  [1];  [2]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  2. SLAC National Accelerator Lab., Menlo Park, CA (United States)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1358294
Alternate Identifier(s):
OSTI ID: 1367853; OSTI ID: 1379855
Grant/Contract Number:
AC02-05CH11231; AC02-76SF00515
Resource Type:
Journal Article: Published Article
Journal Name:
Physical Review Accelerators and Beams
Additional Journal Information:
Journal Volume: 20; Journal Issue: 5; Journal ID: ISSN 2469-9888
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS

Citation Formats

Qiang, J., Ding, Y., Emma, P., Huang, Z., Ratner, D., Raubenheimer, T. O., Venturini, M., and Zhou, F.. Start-to-end simulation of the shot-noise driven microbunching instability experiment at the Linac Coherent Light Source. United States: N. p., 2017. Web. doi:10.1103/PhysRevAccelBeams.20.054402.
Qiang, J., Ding, Y., Emma, P., Huang, Z., Ratner, D., Raubenheimer, T. O., Venturini, M., & Zhou, F.. Start-to-end simulation of the shot-noise driven microbunching instability experiment at the Linac Coherent Light Source. United States. doi:10.1103/PhysRevAccelBeams.20.054402.
Qiang, J., Ding, Y., Emma, P., Huang, Z., Ratner, D., Raubenheimer, T. O., Venturini, M., and Zhou, F.. Tue . "Start-to-end simulation of the shot-noise driven microbunching instability experiment at the Linac Coherent Light Source". United States. doi:10.1103/PhysRevAccelBeams.20.054402.
@article{osti_1358294,
title = {Start-to-end simulation of the shot-noise driven microbunching instability experiment at the Linac Coherent Light Source},
author = {Qiang, J. and Ding, Y. and Emma, P. and Huang, Z. and Ratner, D. and Raubenheimer, T. O. and Venturini, M. and Zhou, F.},
abstractNote = {The shot-noise driven microbunching instability can significantly degrade electron beam quality in x-ray free electron laser light sources. Experiments were carried out at the Linac Coherent Light Source (LCLS) to study this instability. Here in this paper, we present start-to-end simulations of the shot-noise driven microbunching instability experiment at the LCLS using the real number of electrons. The simulation results reproduce the measurements quite well. A microbunching self-heating mechanism is also illustrated in the simulation, which helps explain the experimental observation.},
doi = {10.1103/PhysRevAccelBeams.20.054402},
journal = {Physical Review Accelerators and Beams},
number = 5,
volume = 20,
place = {United States},
year = {Tue May 23 00:00:00 EDT 2017},
month = {Tue May 23 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevAccelBeams.20.054402

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  • The shot-noise driven microbunching instability can significantly degrade electron beam quality in x-ray free electron laser light sources. Experiments were carried out at the Linac Coherent Light Source (LCLS) to study this instability. Here in this paper, we present start-to-end simulations of the shot-noise driven microbunching instability experiment at the LCLS using the real number of electrons. The simulation results reproduce the measurements quite well. A microbunching self-heating mechanism is also illustrated in the simulation, which helps explain the experimental observation.
  • © 2017 authors. Published by the American Physical Society. The shot-noise driven microbunching instability can significantly degrade electron beam quality in x-ray free electron laser light sources. Experiments were carried out at the Linac Coherent Light Source (LCLS) to study this instability. In this paper, we present start-to-end simulations of the shot-noise driven microbunching instability experiment at the LCLS using the real number of electrons. The simulation results reproduce the measurements quite well. A microbunching self-heating mechanism is also illustrated in the simulation, which helps explain the experimental observation.
  • The microbunching instability (MBI) is a well known problem for high brightness electron beams and has been observed at accelerator facilities around the world. Free-electron lasers (FELs) are particularly susceptible to MBI, which can distort the longitudinal phase space and increase the beam’s slice energy spread (SES). Past studies of MBI at the Linac Coherent Light Source (LCLS) relied on optical transition radiation to infer the existence of microbunching. With the development of the x-band transverse deflecting cavity (XTCAV), we can for the first time directly image the longitudinal phase space at the end of the accelerator and complete amore » comprehensive study of MBI, revealing both detailed MBI behavior as well as insights into mitigation schemes. The fine time resolution of the XTCAV also provides the first LCLS measurements of the final SES, a critical parameter for many advanced FEL schemes. As a result, detailed MBI and SES measurements can aid in understanding MBI mechanisms, benchmarking simulation codes, and designing future high- brightness accelerators.« less
  • The microbunching instability (MBI) is a well known problem for high brightness electron beams and has been observed at accelerator facilities around the world. Free-electron lasers (FELs) are particularly susceptible to MBI, which can distort the longitudinal phase space and increase the beam’s slice energy spread (SES). Past studies of MBI at the Linac Coherent Light Source (LCLS) relied on optical transition radiation to infer the existence of microbunching. With the development of the x-band transverse deflecting cavity (XTCAV), we can for the first time directly image the longitudinal phase space at the end of the accelerator and complete amore » comprehensive study of MBI, revealing both detailed MBI behavior as well as insights into mitigation schemes. The fine time resolution of the XTCAV also provides the first LCLS measurements of the final SES, a critical parameter for many advanced FEL schemes. As a result, detailed MBI and SES measurements can aid in understanding MBI mechanisms, benchmarking simulation codes, and designing future high- brightness accelerators.« less
  • A microbunching instability driven by longitudinal space charge, coherent synchrotron radiation, and linac wakefields is studied for the linac coherent light source (LCLS) accelerator system. Since the uncorrelated (local) energy spread of electron beams generated from a photocathode rf gun is very small, the microbunching gain may be large enough to significantly amplify rf-gun generated modulations or even shot-noise fluctuations of the electron beam. The uncorrelated energy spread can be increased by an order of magnitude to provide strong Landau damping against the instability without degrading the free-electron laser performance. We study different damping options in the LCLS and discussmore » an effective laser heater to minimize the impact of the instability on the quality of the electron beam.« less