Li/Li/sub 2/ supersonic nozzle beam

The characterization of a lithium supersonic nozzle beam was made using spectroscopic techniques. It is found that at a stagnation pressure of 5.3 kPa (40 torr) and a nozzle throat diameter of 0.4 mm the ground state vibrational population of Li/sub 2/ can be described by a Boltzmann distribution with T/sub v/ = 195 +- 30/sup 0/K. The rotational temperature is found to be T/sub r/ = 70 +- 20/sup 0/K by band shape analysis. Measurements by quadrupole mass spectrometer indicates that approximately 10 mole per cent Li/sub 2/ dimers are formed at an oven body temperature of 1370/sup 0/K n the supersonic nozzle expansion. This measured mole fraction is in good agreement with the existing dimerization theory

Photon and positive ion production from collisions of superthermal hydrogen atoms with lithium atoms and molecules. [1 to 10 eV, cross sections, emission spectra]

Photon and positive ion production from superthermal collisions of hydrogen atoms with lithium atoms and molecules is reported. These are the first results in the difficult 1 to 10 eV collision regime obtained with recently developed high intensity plasma-arc source of H atoms. These superthermal H atoms (approximately 5 eV average kinetic energy but not velocity selected in these experiments) have been collided with an intense supersonic lithium beam (approximately 10 percent Li/sub 2/; Li/sub 3/ undetectable) with cold internal degrees of freedom (T/sub vib/ = 195/sup 0/K, T/sub rot/ = 70/sup 0/K). The other aspects of the apparatus have been given previously. Low resolution photon and positive ion production in the collision chamber scattering center and also medium resolution; photon production in the magnet chamber between the skimmer and the magnet were detected