Injection and trapping of an intense energetic ion beam in a tokamak

An intense energetic ion beam produced by a magnetically insulated diode is injected tangentially into a small tokamak. The beam is found to be trapped for up to three transit times about the major circumference of the machine. The ions are analyzed by an electrostatic analyzer and good correlation is found between the ion energy and the interpulse transit time. The ions are distributed in energy between 50 and 150 keV. No signals are observed in the absence of a toroidal magnetic field. Trapping for a single transit only is observed for a toroidal magnetic field but no plasma in the tokamak.