CHARGE-TRANSFER IN SLOW COLLISIONS OF NA WITH H+

Collisions between sodium atoms and protons have been investigated usi ng the molecular expansion method. Cross sections are presented for ch arge transfer from the sodium 3s and 3p levels to the hydrogen n = 2 l evel, at collision energies up to 34 eV, to determine rate coefficient s for the temperature range 1000-20 000 K. A quantum-mechanical descri ption of the relative motion has been used with reaction coordinates t o account for electron translation effects. Our results cast doubt on the absolute cross section measurements made by Kushawaha (1983) in la ser excitation experiments.