The relaxation of the energy stored in the translational and rotational degrees of freedom of N2 and CH4 in the course of free jet expansions has been experimentally studied. Rotational temperatures along the expansion axis were obtained by means of stimulated Raman spectroscopy, and terminal flow velocities and translational temperatures were determined from supersonic beam time-of-flight measurements. From these measurements low-temperature cross sections for rotational relaxation have been estimated. The results are compared with data from other experiments, and the validity of simple relaxation models is discussed.

Experimental studies on a pulsed hollow cathode capillary discharge AIP Conf.Double modulationhigh resolution infrared spectroscopic technique: The ν3 band of the CH3 radical and excited states of CH4 in a hollow cathode discharge J. Chem. Phys. 100, 238 (1994); 10.1063/1.466991Mass spectroscopic investigation of the CH3 radicals in a methane rf discharge Appl.

No abstract

The high-resolution (ca. 0.008 cm-') stimulated Raman spectrum of the strongly perturbed C-H symmetric stretching region of 12C2H, at room temperature and at a rotational temperature of ca. 30 K, achieved in a free supersonic jet expansion chamber, is reported. The spectrum is tentatively analysed and assigned in terms of a simplified vihratiow-torsiornotation Hamiltonian. Besides the already known strong Fermi resonance, several Coriolis torsional interactions are identified as the major perturbations in this spectral region.