Freeelectron interactions with light using the inverse Cerenkov effect
Abstract
An analysis and experimental verification of momentum modulation of relativistic electrons by laser light using the inverse Cerenkov effect is presented. As an alternative to the freeelectron laser for achieving energy exchange between particles and photons, the inverse Cerenkov effect uses the index of refraction of a gaseous medium to retard the phase velocity of an electromagnetic wave, enabling the electrons to remain in a field of constant phase. The momentum modulation converts to chargedensity modulation by allowing the electrons to drift, thus forming electron bunches separated by optical wavelengths. An analysis is presented for the maximum amount of energy exchange, the energy exchange distribution, and the optimum bunching distance. A computer simulation of the interaction process is also given. These results are compared with the observed momentum modulation of a 102 MeV electron beam by a 30 MW Nd:YAG 1.06 micron laser in both hydrogen and methane gases. Initial observation of coherent optical radiation from a 57 MeV electron beam using the same laser system is also presented. Laserdriven particle accelerators and optical klystrons are possible applications of this interaction.
 Publication:

IEEE Journal of Quantum Electronics
 Pub Date:
 August 1981
 DOI:
 10.1109/JQE.1981.1071281
 Bibcode:
 1981IJQE...17.1507E
 Keywords:

 Cerenkov Radiation;
 Free Electrons;
 Inverse Scattering;
 Laser Outputs;
 PhotonElectron Interaction;
 Relativistic Electron Beams;
 Computerized Simulation;
 Electron Bunching;
 Electron Energy;
 Klystrons;
 Monte Carlo Method;
 Particle Accelerators;
 Lasers and Masers