Vibrational energy transfer for H2-D2 and H2-HCl mixtures from 220-450 K

A laser fluorescence technique is used for the direct observation of the vibrational relaxation of H2 in the presence of D2 and HCl. The technique used is much simpler than the Raman absorption laser-schlieren method and has the advantage that the direct observation of changes in the vibrational energy of H2 permits the study of V-V relaxation processes in mixtures of H2 with other gases. The rapid V-V transfer between HF and H2 is used to permit the selective vibrational excitation of H2 by trace amounts of HF excited by laser absorption. The subsequent relaxation of vibrational energy from the coupled HF and H2 molecules is monitored by the laser induced fluorescence of HF.