Electron Prebunching with Space-Charge Effects

Computation results are presented on electron prebunching, including space-charge effects, which lead to a practical formulation useful for designers. A computer program has been established for an electron beam radially uniform. Results are presented on compression for different parameters : current, electrical field of modulation, focussing magnetic field. A phenomenological interpretation of the bunching and of the following beam blow up due to space-charge is given. The results given by the computation program allow the choice of a simplified model leading to a practical expression for the compression as a function of the main parameters.