Kinetics of atomic hydrogen in an expanding magnetized low-pressure plasma

The abs. d. of at. hydrogen excited states in a magnetized expanding thermal plasma is detd. using emission and absorption spectroscopy. Depending on the conditions a population inversion is obsd. between the quantum states 3 ? p ? 7. It is argued that mol. induced mutual recombination reactions of pos. ions with neg. ions should play an important role on hydrogen at. level population. The abs. population d. of hydrogen in the first excited state and a simple kinetic scheme were used to derive information on the abs. d. of at. hydrogen in the ground state and dissocn. degree of hydrogen plasma. The properties of the charged particles in the plasma have been obtained from single and double Langmuir probe diagnostics. First evidences have been found for the presence of high densities of the neg. ions in an expanding hydrogen plasma. [on SciFinder (R)]