Spherical microwave electrode discharge. Phenomenology and results of probe measurements

A description is given of an initiated microwave ball discharge generated at the end of an antenna in a metal discharge chamber whose dimensions are substantially greater than those of the glowing plasma zone. The experiments were carried in hydrogen at pressures of 1-15 Torr. The double electric probe method was used to investigate the plasma structure. The Boltzmann equation was used to estimate the microwave field strengths corresponding to the measured values of the electron temperature near the glowing region of the discharge. It is shown that the spatial structure of the field corresponds to the field structure of a surface wave propagating along the discharge surface. The existence of such a wave can explain the increase in the plasma radiation intensity at its boundary. (C) 1998 American Institute of Physics. [S1063-7842(98)00512-1].