Visible light emitted by electrons and positrons from an undulator

Abstract

Currently in the SPS, visible light emitted by p and p in an undulator is used to measure profiles of the circulating beam. This paper shows how, when the SPS will operate as LEP injector, an identical undulator placed in another configuration can also be used to measure the lepton beam profiles. A simple method to separate the visible light from the high power X-rays is proposed. Power emitted in the visible range and the diffraction effects are calculated and should permit enough accuracy in the transverse beam profile measurements.