Plasma Propagation into Low-Pressure Gas and Plasma in a Magnetic Field

摘要

The propagation of plasma into an ambient gas at low pressure in the presence of an external electric field was investigated experimentally and theoretically. The important feature is the slow speed of plasma expansion which is of interest in the problem of plasma containment. A possible connection with space physics was sought but not found. The positive column of an arc discharge with and without an external magnetic field was investigated spectroscopically using the singlet-triplet ratio method in helium. Analysis of results showed that the electron-velocity distribution function was not Maxwellian near the wall of the discharge tube. Transfer of the uniform column to the helical form at the critical value of the magnetic field was demonstrated without perturbing the plasma in any way. (Author)