Rotational Relaxation of the Levels of the B State in ~(127)I and ~(129)I Molecular Iodine Isotopes Excited by 633-nm Radiation of a He-Ne Laser

摘要

We determine the cross sections of rotational relaxation for vibrational-rotational levels of the B state in ~(127)I and ~(129)I molecular iodine isotopes excited by 633-nm radiation of a He-Ne laser. The efficiency of rotational energy transfer is investigated as a function of the number of the level being excited and the properties of colliding particles. Our studies demonstrate that the efficiency of rotational relaxation is at least 1.5-2 orders of magnitude higher than the efficiency of other processes of collisional relaxation in molecular iodine, such as collisional predissociation and vibrational relaxation. It is shown that the rate of rotational relaxation is a rather weak function of the number of a vibrational level, but depends considerably on the properties of particles colliding with an excited iodine molecule, including the mass and the geometry of a buffer gas.