Neutral resonant ionization in a H⁻ plasma source: Potential of doubly excited **H⁻.

Abstract

Hydrogen plasmas are optically dense to Lyman-α radiation, maintaining *H(n = 2) neutral atoms that may undergo neutral resonant ionization to **H(-). One state, **H(-)(2p(2) (3)P(e)), is thought bound at 9.7 meV with a several nanosecond lifetime while all others are unbound resonances. Collision dynamics of two *H(2s) shows that an ionic pair of (p, **H(-)) resolves at least three long-standing collision experiments. The doubly excited anion also has a path to the unexcited ion pair whose only physical distinction is that both (p, H(-)) have energy of 3.7 eV.