Author : Anuradha Bhasin, Risheek Kumar and Monica Kaushik

The Cerenkov free electron laser (CFEL) model under consideration consists of a pre-bunched relativistic electron beam and a dielectric loaded waveguide. The increase in the growth rate using a pre-bunched electron beam in a Cerenkov free electron laser (CFEL) has been studied. The growth rate as a function of modulation index has been studied and calculated at experimentally known CFEL parameters. The growth rate of the CFEL is found to increase with the modulation index and reaches maximum when the modulation index approaching unity in addition to the frequency and wave number of the pre-bunched beam are comparable to that of the radiation wave, i.e., when the pre-bunched beam velocity is comparable to the phase velocity of the radiation wave.

Keywords: Pre-bunched electron beam, Cerenkov free electron laser, Cerenkov emission, efficiency, Growth rate, modulation index, slow wave device.

Article published in International Journal of Current Engineering and Technology, Vol.5, No.3 (June-2015)