WEZD4
LANL, Los Alamos, New Mexico, USA
LBNL, Berkeley, California, USA
SLAC, Menlo Park, California, USA
University of Chicago, Chicago, Illinois, USA
A novel diagnostic has been developed that uses off-axis undulator radiation to characterize the longitudinal bunch profile of an electron beam. The diagnostic uses a small, ~0.1-m long undulator with mirrors that focus the undulator radiation onto an array of pyrometers. The mirrors both focus the radiation onto the pyrometer and remove the chirping effect that comes from the finite length of the undulator. Numerical and analytical models have been developed to calculate the radiation for a given bunch length, and a phase retrieval algorithm has been developed to extract the bunch profile from measured data. The diagnostic has been installed at the BELLA laser-plasma wakefield accelerator, and will be used to characterize the bunch length there. The concept and relevant results will be presented.
