Effect of electron beam divergence on the width of spectral peaks in single-mode interfered transition radiation

We observed the effect of variation in the radiation angle, which originated from electron beam divergence, size, and measurement geometries, on the widths of spectral peaks in X-rays produced by single-mode interfered transition radiation (SM-ITR). For two different beam conditions, which mainly produced different electron beam divergences, we measured the X-ray spectra of SM-ITR from a multilayer target which was bombarded by 15-MeV electrons. The experimental results show that the width of the spectral peaks is sensitive to a small change in the variations in radiation angle. This result means that the control of electron beam divergence is very important to the realization of truly fine SM-ITR spectra. (C) 2001 Elsevier Science B.V, All rights reserved.