Design of instantaneous measurement system based on optical transition radiation

An optical transition radiation (OTR)-based measurement system has been designed to obtain the instantaneous beam divergence and spot size of Dragon-Ⅰ linear induction accelerator (LIA) simultaneously. It can achieve instantaneous measurement within about 10 ns, and provides an on-line instantaneous beam diagnostic method for a 18.5 MeV, 2 kA, 90 ns electron pulse. The typical results of beam spot and beam divergence are about 9 mm and 10.5 mrad. This system lays a foundation for the study of time-resolved beam diagnostic technique which will be adopted in Dragon-Ⅰ LIA.