Free-Free Bremsstrahlung from a Plasma with an Anisotropic Electron Velocity Distribution

Measurements of two properties of the emitted free-free bremsstrahlung from an electron cyclotron resonance plasma were made. These were the radiation intensity and the spatial distribution of the photons as a function of angle with respect to the magnetic field axis. The intensity was maximum for directions of observation along the field lines. The spectral distribution showed that the average emitted x-ray photon was more energetic along the field lines than across them. A theoretical development has been made which considers quantum-mechanical, nonrelativistic transitions, which correspond to the conditions of the experiment. The theory predicts the observed measurements and also, in the limit of low energy photons, (nonquantum mechanical transitions) corresponds to previous developments.