Open AccessUsing Emittance Partitioning Instead of a Laser Heater to Suppress the Microbunch Instability
Author(s) -
Bruce E. Carlsten,
Kip A. Bishofberger,
Leanne D. Duffy,
John W. Lewellen,
Quinn R. Marksteiner,
Nikolai A. Yampolsky
Publication year - 2016
Publication title -
ieee transactions on nuclear science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.537
H-Index - 122
eISSN - 1558-1578
pISSN - 0018-9499
DOI - 10.1109/tns.2015.2498619
Subject(s) - nuclear engineering , bioengineering
At the Linac Coherent Light Source (LCLS) X-ray free-electron laser, a laser “heater” is used to generate an uncorrelated 20-keV energy spread on an electron beam to suppress the microbunching instability in downstream bunch compressors. Here we describe an alternative approach using emittance partitioning, where the increase in energy spread is generated by moving phase space volume from the transverse dimensions into the longitudinal dimension. For LCLS-relevant beam parameters, about a factor of six reduction in the product of both transverse emittances is feasible with the same amount of induced energy spread, with additional improvements possible with an optimized setup.