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.