Physical Assembly Research Articles

Highly Ionized, Steady-State Plasma System

A system is described which produces a steady-state helium plasma with greater than 95% ionization. The primary plasma is generated in a modified Phillips ion gauge discharge and diffuses along a magnetic field (B ∼ 1 kG) through a region in which neutral particles are preferentially removed. In the downstream region a plasma density of ∼2 × 1013 cm−3 and ion temperatures up to 10 eV have been achieved. The present paper describes the over-all physical assembly, the operating characteristics of the system, and the nature of the plasma that is produced. In addition, a discussion of processes believed important in its operation is given.