EXPERIMENTAL STUDY OF RESONANT RF DISCHARGES.

Steady-state rf discharges in mercury vapor are investigated at excitation frequencies f equals 40. 8 - 110 MHz near the geometric-resonance frequency of the discharge gap, omega //p. Experiments are carried out for mercury vapor pressures over the range p//0 equals 10** minus **4 - 10** minus **2 torr. The condition for a resonant rf discharge ( omega equals omega //p) is established: a minimum voltage across the discharge. Conditions are determined experimentally in which the discharge characteristics are near their resonant values (the discharge is quasiresonant) over a broad range of discharge voltages and mercury vapor pressures. The condition for a quasiresonant discharge is determined.