AN EXPERIMENTAL-STUDY OF THE DEVIATION FROM EQUILIBRIUM IN A HIGH-PRESSURE MICROWAVE HELIUM PLASMA PRODUCED BY AN AXIAL INJECTION TORCH

The distribution of atomic states for a helium plasma torch at high (a tmospheric) pressure has been determined by calculating the population s of some excited states of the neutral helium system by means of diff erent spectroscopic techniques. A plasma not close to local thermodyna mic equilibrium was found. The overpopulation of some states showed th at it was an ionizing plasma with the equilibrium deviation parameter of the ground state, bl, of about 100. The population of the excited s tates closely obeyed the p(-6) law, where p is the effective principal quantum number.