Abstract

We have measured the bremsstrahlung emission from a thick target to determine the electron beam movement and distribution in our Raman free-electron laser. The principle of the method and measurement results of the electron distribution in the diode and drift tube of the Raman free-electron laser are presented. Based on such a diagnosis, the optimum free-electron laser operating conditions were determined, and the performance of the laser was improved significantly. The electronic efficiency of the free-electron laser was increased by about an order of magnitude to 0.8% for a cusp wiggler and 1.4% for an electromagnetic wiggler.

© 1987 Optical Society of America