Relativistic nonthermal radiation in the HL-1 device

Non-thermal millimeter radiation from the plasma in the HL-1 device has been investigated at two fixed frequencies (80 GHz and 35 GHz) by means of two superheterodyne receivers which are set up in a direction vertical to the major radius. In view of the relation between this radiation and the plasma density, discharges in HL-1 can be classified into four types. Two critical values of density are found. Runaway properties and phenomena pertaining to runaway kinetic instability are thought to be related to this radiation. A series of macroscopic phenomena and losses caused by the runaway kinetic instability are also investigated