Vibrational pumping of H-2 molecules in a hydrogen stream flowing through a cesium-hydrogen discharge

The H-2 molecular vibrational distribution function that is formed in a flo w of molecular hydrogen is calculated. It is assumed that the hydrogen stre am flows in a planar channel and passes through two sections in succession. In the first section a cesium-hydrogen discharge and preliminary vibration al pumping of H-2 molecules occur. In the second section, where there is no discharge, the upsilon-upsilon exchange process results ina considerable i ncrease in the density of vibrationally excited molecules in a certain uppe r part of the vibrational spectrum. The possibility of using the vibrationa l distribution function produced in this manner to generate negative hydrog en ions as a result of subsequent dissociative attachment of electrons to v ibrationally excited molecules is discussed. (C) 1998 American Institute of Physics. [S1063-7842(98)00210-4].