Inelastic collisions in para-H2: translation-rotation state-to-state rate coefficients and cross sections at low temperature and energy.
We report an experimental determination of the k(00-->02) rate coefficient for inelastic H(2):H(2) collisions in the temperature range from 2 to 110 K based on Raman spectroscopy data in supersonic expansions of para-H(2). For this purpose a more accurate method for inverting the master equation of rotational populations is presented. The procedure permits us to reduce the measured k(00-->02) rate coefficient to the corresponding sigma(00-->02) cross section in the range of precollisional energy from 360 to 600 cm(-1). Numerical calculations of sigma(00-->02) carried out in the frame of the coupled channel method are also reported for different intermolecular potentials of H(2). A good agreement is found between the experimental cross section and the numerical one derived from Diep and Johnson's potential [J. Chem. Phys. 112, 4465 (2000)].
Maté
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Instituto de Estructura de la Materia, CSIC Serrano 121, 28006 Madrid, Spain.
Thibault
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F
Tejeda
G
G
Fernández
J M
JM
Montero
S
S