SUPERTHERMAL ELECTRONS IN THE TJ-IU TORSATRON

The generation and behaviour of superthermal electrons are studied as a function of magnetic configuration in the TJ-IU torsatron. Character ization of fast electrons is carried out with soft x-ray (SXR) and har d x-ray (HXR) diagnostic systems;, covering the range from 0.4 keV to several MeV. The mean energies reached by the superthermal electron po pulations are found to be consistent with the occurrence of electron c yclotron (EC) off-axis absorption for the different radial magnetic fi eld ripples at the axis. The interpretation of the experimental observ ations has been based on the influence of trapping factors at the magn etic axis and electron density profiles in the superthermal electron m ean energy and density.