Short Pulse X-rays at Jefferson Lab

(FR-1-02) Presenting Author: James Boyce (Invited)

J. R. Boyce, G. A. Krafft, S. Benson, D. R. Douglas, H. F. Dylla, K. Jordan, L. Merminga, G. Neil, P. Piot, M. Shinn, and U. Happek  

Thomas Jefferson National Accelerator Facility and University of Georgia

Sub-picosecond pulse length X-rays have been produced at the Jefferson Lab Infrared Free Electron Laser by Thomson scattering of the electron beam off the short-pulse infrared light circulating in the laser. The X-rays are produced by double backscattering yielding a source with unique properties. The number of X-rays per pulse ($\tilde{\hspace{0.4em}}$100-1000) is relatively small compared to anticipated Fourth Generation light sources, but the source has a very high repetition rate (37.5 MHz), yielding total X-ray fluxes exceeding recent work reported by Lawrence Berkeley National Laboratory by several orders of magnitude. More significantly, the polarized X-rays are highly time-correlated with the high average power short-pulse infrared light extracted from the laser, which allows a host of time-resolved pump-probe or stroboscopic applications to be anticipated. In this report we present information on source performance and potential applications. Even the first measurements had very low backgrounds, and a data rate well-matched to fairly simple photon counting electronics.