Investigations on a pulsed electrodeless ring discharge with magnetic bias fields of different amplitudes

摘要

The formation of a plasma in an electrodeless ring discharge with a steady magnetic bias field of different amplitudes was investigated. Internal and external magnetic fields and the intensities of suitable spectral lines were measured. The temporal behaviour of the discharge was observed with a streak camera. It was possible to measure the electron temperature and to estimate the electron density in interesting time intervals. The results show that the obtained electron temperatures essentially depend on the initial magnetic field. This is caused by different amounts of trapped field in the first current halfcycle, which give high magnetic field gradients in the second current halfcycle. End losses are also strongly influenced by the presence of a steady magnetic field.