Inelastic collisions in para-H_2:Translation-rotation state-to-state rate coefficients and cross sections at low temperature and energy

摘要

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 110K 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 k_(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)].