Effects of charge density rise time upon Cerenkov radiation

Abstract

This study investigates the effects of different charge density rise times upon the magnitude of the Cerenkov radiation produced by a semi-infinite electron beam. The magnetic field pulses were generated for different rise times and relationships between the maximum magnitudes and their associated rise times were obtained. These were compared with theoretical relationships derived from a power series approximation. The generated results were close to those predicted by theory for short rise times at short radial distances. For longer rise times, the departure from theory was caused by the magnitude of the decay portion of the magnetic pulse. This effect could be mitigated at longer rise times by increasing the radial distance from the electron beam.