Stimulated Compton conversion of Langmuir waves by relativistic electron beams

Abstract

Stimulated inverse Compton conversion in which a Langmuir wave scatters off a relativistic electron while converting into a transversely polarized electromagnetic wave is considered as a means for producing amplified electromagnetic radiation from a beam-plasma system at frequencies well above the electron plasma frequency. The stimulated emission growth rates of the radiation produced by a monoenergetic ultrarelativistic electron beam are determined as a functional of the Langmuir turbulence spectrum in the background plasma and are numerically evaluated for a range of model Langmuir spectra. Stimulated inverse Compton conversion can play a role in emission from astrophysical beam-plasma systems if the electron beam is highly relativistic and sufficiently narrow. However, it is found that the growth rates for this process are too small in all cases studied to account for the intense high-frequency radiation observed in the laboratory experiments of G. Benford et al. [G. Benford, D. Tzach, K. Kato, and D. F. Smith, Phys. Rev. Lett. 45, 1182 (1980); K. G. Kato, G. Benford, and D. Tzach, Phys. Rev. Lett. 50, 1587 (1983); K. G. Kato, G. Benford, and D. Tzach, Phys. Fluids 26, 3636 (1983)].