Kinetic and internal energy distributions via velocity-aligned Doppler spectroscopy: The 193 nm photodissociation of H/sub 2/S and HBr

Journal Article · Wed Jul 15 04:00:00 EDT 1987 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.453339· OSTI ID:6449802

Xu, Z; Koplitz, B; Wittig, C

We report center-of-mass kinetic energy distributions for the 193 nm photodissociation of H/sub 2/S and HBr using the method of velocity--aligned Doppler spectroscopy. Nascent H atoms are detected by sequential two-photon photoionization via Lyman-..cap alpha.. (121.6 nm + 364.7 nm), and internal SH(X /sup 2/Pi) and Br excitations are observed directly in the H-atom kinetic energy distributions. The kinetic energy resolution is much better than in ''conventional'' sub-Doppler resolution spectroscopy and results from detecting spatially selected species whose velocities are aligned with the wave vector of the probe radiation, k/sub probe/, thereby providing a kinetic energy distribution for a specific laboratory direction. This improved resolution is achieved in the present experiments by using pulsed, collimated, and overlapped photolysis and probe beams, but the vital aspect of the technique involves increasing the delay between the two lasers in order to discriminate against species having velocity components perpendicular to k/sub probe/.

• Research Organization: Chemistry Department, University of Southern California, Los Angeles, California 90089-0484
• OSTI ID: 6449802
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 87:2; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
DISSOCIATION
DISTRIBUTION
ENERGY
HYDROBROMIC ACID
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
INORGANIC ACIDS
KINETIC ENERGY
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RESOLUTION
SULFIDES
SULFUR COMPOUNDS