RADIATION FROM ELECTROSTATIC DOUBLE-LAYERS IN LABORATORY PLASMAS

Experiments on the radiation from strong electrostatic double layers a re performed in a double plasma machine. The spectra show that double- layer-related emission exists next to global plasma phenomena. We find evidence for a scattering process at low frequencies, a linear accele ration emission mechanism at frequencies,below the-ambient plasma freq uency and beam-plasma interaction at the anode side of the double laye r at frequencies around 300 MHz. The brightness temperature of the emi tted radiation is approximately two to three orders of magnitude highe r than the temperature of the plasma.