Spectroscopic study of high energy excited deuterium atoms in a hollow cathode glow discharge

The presented results are concerned with the shape of the Balmer alpha line emitted from a low pressure dc glow discharge with stainless steel (SS) and titanium (Ti) hollow cathode (HC) with D-2 or Ar/D-2/H-2 gas mixture. The analysis indicates that the line profile represents a convolution of three Gaussian profiles resulting from different collision excitation processes. The average energy of excited deuterium atoms determined from the width of the broadest Gaussian is about 86 eV in both HCs. In Ar/D-2/H-2 gas mixtures, the energies are in the range from 33 eV to 47 eV, but with much larger contribution of this Gaussian to the Balmer alpha profile. In discharges with hydrogen isotopes, the energy derived from the medium-width Gaussian is in the range from 4 eV to 6 eV, while in gas mixtures it is between 1 eV and 2 eV. The width of the narrowest Gaussian slightly exceeds the instrumental broadening and it is always below 0.5 eV.(c) c 2007 American Institute of Physics.