INTEGRAL CROSS-SECTIONS FOR IONIZING PROCESSES IN HYDROGEN-ATOM HYDROGEN MOLECULE COLLISIONS AT LOW-ENERGY

We report integral cross sections for the collision processes between H(D) atoms and H-2(D-2) molecules in the energy range from threshold t o 170 eV leading to charged collision products. We observe not only ch arge exchange and target or projectile ionization such as H + H-2 --> H- + H-2(+) and H + H-2 --> H + e + H-2(+) but also associative ioniza tion, H + H-2 --> H-3(+) + e, and heavy particle exchange, D + H-2 --> HD+ + H-. Typical absolute cross section values are between 10(-21) c m(2) and 10(-17) cm(2).