Emittance compensation with dynamically optimized photoelectron beam profiles. Rosenzweig, J. B.; Cook, A. M.; England, R. J.; Dunning, M.; Anderson, S. G.; and Ferrario, M. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 557(1):87--93, February, 2006.
Emittance compensation with dynamically optimized photoelectron beam profiles [link]Paper  doi  abstract   bibtex   
Much of the theory and experimentation concerning creation of a high-brightness electron beam from a photocathode, and then applying emittance compensation techniques, assumes that one must strive for a uniform density electron beam, having a cylindrical shape. On the other hand, this shape has large nonlinearities in the space-charge field profiles near the beam's longitudinal extrema. These nonlinearities are known to produce both transverse and longitudinal emittance growth. On the other hand, it has recently been shown by Luiten that by illuminating the cathode with an ultra-short laser pulse of appropriate transverse profile, a uniform density, ellipsoidally shaped bunch is dynamically formed, which then has linear space-charge fields in all dimensions inside of the bunch. We study here this process, and its marriage to the standard emittance compensation scenario that is implemented in most recent photoinjectors. It is seen that the two processes are compatible, with simulations indicating a very high brightness beam can be obtained. The robustness of this scheme to systematic errors is examined. Prospects for experimental tests of this scheme are discussed.
@article{ rosenzweig_emittance_2006,
  series = {Energy Recovering Linacs 2005 Proceedings of the 32nd Advanced {ICFA} Beam Dynamics Workshop on Energy Recovering Linacs 32nd Advanced {ICFA} Beam Dynamics Workshop on Energy Recovering Linacs},
  title = {Emittance compensation with dynamically optimized photoelectron beam profiles},
  volume = {557},
  issn = {0168-9002},
  url = {http://www.sciencedirect.com/science/article/pii/S0168900205019789},
  doi = {10.1016/j.nima.2005.10.055},
  abstract = {Much of the theory and experimentation concerning creation of a high-brightness electron beam from a photocathode, and then applying emittance compensation techniques, assumes that one must strive for a uniform density electron beam, having a cylindrical shape. On the other hand, this shape has large nonlinearities in the space-charge field profiles near the beam's longitudinal extrema. These nonlinearities are known to produce both transverse and longitudinal emittance growth. On the other hand, it has recently been shown by Luiten that by illuminating the cathode with an ultra-short laser pulse of appropriate transverse profile, a uniform density, ellipsoidally shaped bunch is dynamically formed, which then has linear space-charge fields in all dimensions inside of the bunch. We study here this process, and its marriage to the standard emittance compensation scenario that is implemented in most recent photoinjectors. It is seen that the two processes are compatible, with simulations indicating a very high brightness beam can be obtained. The robustness of this scheme to systematic errors is examined. Prospects for experimental tests of this scheme are discussed.},
  number = {1},
  urldate = {2014-10-16TZ},
  journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment},
  author = {Rosenzweig, J. B. and Cook, A. M. and England, R. J. and Dunning, M. and Anderson, S. G. and Ferrario, Massimo},
  month = {February},
  year = {2006},
  keywords = {Brightness, Collective effects, Electron source, Space-charge, emittance},
  pages = {87--93}
}
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