Synchrotron radiation from the hot electron rings in EBT

Abstract

The spectrum of the synchrotron radiation emitted by the relativistic electron rings in the ELMO Bumpy Torus (EBT) has been formulated. A computer code (CYCLO has been developed for the numerical calculations for the range of frequencies (especially higher harmonics) and temperatures (approx. 0.1 to 2 MeV) of interest. The analysis has been carried out for various classes of isotropic (not necessarily Maxwellian) and anisotropic ring electron distribution functions. Calculations include the radial profiles of the ring electron density and temperature (approximated from fits to the experimental data) and include consistent magnetic field modifications (magnetic well due to high-beta ring) deduced from the pressure balance. The calculated spectra and emission levels for the Maxwellian distribution are in reasonable agreement with those measured, though detailed comparisons of theory and experiment have not been made. Because of the relativistic temperatures, the radiation is predominantly in higher harmonics. The spectrum of emission for each harmonic indicates broadening of individual lines with large frequency widths that causes pronounced overlapping of harmonics and results in a monotonically decreasing spectrum as observed in the experiments.