Study on interference between far-IR to mm-wave CSR from consecutive electron bunches at BFEL RF-Linac

Abstract

Coherent bending magnet or undulator radiation due to a train of electron bunches is treated as radiation from a multi-slit diffraction array. Based on this model, we numerically analyse the interference among coherent synchrotron radiation emitted from consecutive bunches in a train of bunches, which are accelerated by a 30-MeV RF-linac at BFEL. Some interesting results are as follows: (1) Rapidly oscillating radiation enhancement due to interbunch interference is overlapped on the single bunch spectrum. (2) It consists of a series of spectrum lines corresponding to harmonics of the RF fundamental. (3) Main maximum positions are determined by the “diffraction condition”. (4) Total intensity is about the square of the number of bunches participating in interference as single bunch intensity. Experimental design to measure interbunch interference at BFEL with the sub-mm and mm-wave Michelson interferometer is presented.