Emission bands from discharge-excited alkali-noble-gas systems

The discharge emission spectrum in the visible and near IR from Cs or Rb vapor mixed with Xe, Kr, or Ar (of density >~ 1 amagat) is studied. For a heavy noble gas at high density, the discharge spectrum features strong emission bands from alkali-noble-gas excited molecules correlated with the lowest S or D excited states, or with P excited states, of the alkali atom. The emission bands are remarkably similar to the laser-excited emission bands reported previously.