Spectroscopic Study of a Highly Ionized Hydrogen Plasma

Experimental details are given for time- and space-resolved determinations of electron temperature and density in a highly ionized, decaying-hydrogen plasma. The technique used involves absolute intensity measurements of the Hβ line and of two widely separated portions of the continuum. A carbon arc is used as a radiation standard. The inferred ion density agrees satisfactorily with that deduced from Stark broadening of the Hβ line. Internal consistency among various methods of inferring a temperature indicates when and where the technique yields reliable results. It is shown that the plasma (Ne ≈ 4 × 1015 cm−3, Te ≈ 1 to 2 × 104 °K), which is produced in a long cylinder in a strong axial magnetic field, decays by volume recombination. Diffusion losses appear to be negligible.