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Title: Ultraviolet laser transverse profile shaping for improving x-ray free electron laser performance

Journal Article · · Physical Review Accelerators and Beams
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The photocathode rf gun is one of the most critical components in x-ray free electron lasers. The drive laser strikes the photocathode surface, which emits electrons with properties that depend on the shape of the drive laser. Most free electron lasers use photocathodes with work function in the ultraviolet, a wavelength where direct laser manipulation becomes challenging. In this paper, we present a novel application of a digital micromirror device (DMD) for the 253 nm drive laser at the Linear Coherent Light Source. Laser profile shaping is accomplished through an iterative algorithm that takes into account shaping error and efficiency. Next, we use laser shaping to control the X-ray laser output via an online optimizer, which shows improvement in FEL pulse energy. Lastly, as a preparation for electron beam shaping, we use the DMD to measure the photocathode quantum efficiency across cathode surface with an averaged laser rms spot size of 59 μm. In conclusion, our experiments demonstrate promising outlook of using DMD to shape ultraviolet lasers for photocathode rf guns with various applications.

Research Organization:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC02-76SF00515
OSTI ID:
1375519
Alternate ID(s):
OSTI ID: 1390320
Journal Information:
Physical Review Accelerators and Beams, Journal Name: Physical Review Accelerators and Beams Vol. 20 Journal Issue: 8; ISSN 2469-9888
Publisher:
American Physical SocietyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 9 works
Citation information provided by
Web of Science

References (23)

Experimental Generation and Characterization of Uniformly Filled Ellipsoidal Electron-Beam Distributions journal June 2008
Photocathodes for the energy recovery linacs
  • Rao, T.; Burrill, A.; Chang, X. Y.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 557, Issue 1 https://doi.org/10.1016/j.nima.2005.10.112
journal February 2006
Emittance compensation with dynamically optimized photoelectron beam profiles
  • Rosenzweig, J. B.; Cook, A. M.; England, R. J.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 557, Issue 1 https://doi.org/10.1016/j.nima.2005.10.055
journal February 2006
Projection displays and MEMS: timely convergence for a bright future conference September 1995
Impact of the spatial laser distribution on photocathode gun operation journal September 2012
Optical Shaping of X-Ray Free-Electron Lasers journal June 2016
Review of x-ray free-electron laser theory journal March 2007
High-brightness electron beam evolution following laser-based cleaning of a photocathode journal September 2012
Commissioning the Linac Coherent Light Source injector journal March 2008
Femtosecond laser pulse shaping by use of microsecond radio-frequency pulses journal January 1994
Adaptive electron beam shaping using a photoemission gun and spatial light modulator journal February 2015
Terawatt x-ray free-electron-laser optimization by transverse electron distribution shaping journal November 2014
Demonstration of cathode emittance dominated high bunch charge beams in a DC gun-based photoinjector journal March 2015
Cathode R&D for future light sources
  • Dowell, D. H.; Bazarov, I.; Dunham, B.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 622, Issue 3 https://doi.org/10.1016/j.nima.2010.03.104
journal October 2010
A new high-brightness electron injector for free electron lasers driven by RF linacs
  • Fraser, J. S.; Sheffield, R. L.; Gray, E. R.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 250, Issue 1-2 https://doi.org/10.1016/0168-9002(86)90862-4
journal September 1986
Genetic-algorithm-based method to optimize spatial profile utilizing characteristics of electrostatic actuator deformable mirror journal May 2008
Low-emittance electron-beam generation with laser pulse shaping in photocathode radio-frequency gun journal August 2002
Design and Performance of the Cornell ERL DC Photoemission Gun conference January 2009
Envelope analysis of intense relativistic quasilaminar beams in rf photoinjectors:mA theory of emittance compensation journal June 1997
How to Realize Uniform Three-Dimensional Ellipsoidal Electron Bunches journal August 2004
Maximum Achievable Beam Brightness from Photoinjectors journal March 2009
Laser pulse shaping for generating uniform three-dimensional ellipsoidal electron beams journal February 2009
Efficient temporal shaping of electron distributions for high-brightness photoemission electron guns journal April 2008

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