Excited-state atomic-hydrogen population resulting from 10-keV proton and 20-keV H+2 beams colliding with a magnesium vapor target

Investigations are made of the production of excited-state hydrogen neutrals using 10-keV proton or 20-keV $H_2^{{}^{+}}$ beams and a magnesium vapor cell. Optical measurements are used to determine the population of the n=6 level as a function of target thickness and to determine the relative populations for 3≤n≤8. The cross section for capture into the n=6 level for incident $H_2^{{}^{+}}$ is found to be about equal to that for incident protons. An approximate $\frac{1}{n^3}$ dependence of the excited-state populations is found for n≥6 with an assumed $2l+1$ weighted substate distribution.