Electron loss from H(3p) atoms in collision with H₂molecules and rare-gas atoms. Intense H(3p) beam production by laser excitation of metastable hydrogen

A method of producing an intense beam of H(3p) atoms is described. The 3p hydrogen atoms are formed by laser excitation of metastable H(2s) atoms and efficiencies of the order of 0.3 to 0.4 are easily obtained. The metastables themselves are formed by the charge exchange of protons in a Cs vapour. Cross sections for electron loss from H(3p) atoms and H(2s) atoms in collision with H 2 molecules and rare-gas atoms have been measured in the energy range 1260-3600 eV in the forward direction (10 mrad acceptance). The results are normalised to absolute cross sections obtained by Roussel et al. (1977) for electron loss from ground-state hydrogen atoms in collision with the same targets. Comparison with other measurements is only possible for electron loss from H(2s) atoms and a good agreement with other authors is found.