Simulation for measurement technique of electron beam divergence basing on Cherenkov radiation

The direction of Cherenkov Radiation (CR) light is strictly defined by the direction along which the charged particle moves. This characteristic can be adopted to measure the electron beam divergence and it is a hopeful method. The Coulomb force on electron in the convertor expand the beam divergence and obviously reduce the measurement precision. A model of multi-slice in cascade connection is adopted to constitute convertor configuration. Taking into account the combined effect of Coulomb force, multiple scattering, bremsstrahlung and ionization, the deviation process of electron in the convertor material is then simulated by Monte-Carlo simulation. Measurement technique of electron beam divergence is further simulated basing on the principle of exact corresponding relationship between electron beam divergence distribution and CR photon distibution. Some effect on measurement are obtained for factors including convertor material, thickness, beam energy divergence and optical bandwidth of measurement system. The simulated results give many useful suggestions for the design of the measurement system and the image data processing. The simulation results obviously show the feasibility of electron beam divergence measurement basing on Cherenkov radiation and that its distribution can also be measured in a certain extent.