ARC-HEATED MAGNETICALLY TRAPPED EXPANDING PLASMA-JET GENERATOR

For the purpose of new applications of thermal and recombining plasma, an apparatus is developed which continuously produces ''arc-heated and magnetically trapped expanding plasma jet.'' In this apparatus, arc-heated thermal helium plasma of atmospheric pressure is spouted from a nozzle of 1.2 mm inner diameter into a rarefied gas wind tunnel of about 3-20 Pa with a parallel magnetic field of 0.025-0.16 T. Investigations about the plasma are carried out and stationary inverted populations are observed downstream along this plasma jet. The magnetic field establishes stable arc discharge. Electron temperature T(e), ion temperature T(i), and electron density n(e) of the plasma are about 0.1-1, 0.1-0.8 eV, and 1 X 10(12) X 10(13) cm-3, respectively. Two examples of applications of this apparatus are discussed. One is a potential active laser medium, and the other is a cluster preparer.