Single and double electron capture in H+ on Kr collisions at low-keV energies

Abstract

Abstract Absolute differential and total cross sections for single and double electron capture were measured from H + ions on krypton in the energy range of 1.0 to 5.0 keV. Both differential cross sections exhibit well-resolved oscillations over the range of angles and energies studied. Results are discussed and compared with semiempirical models and with previous measurements, showing good agreement. 1. Introduction Electron capture processes of H ÷ ions in collisions with krypton are of great importance in the fields of thermonuclear fusion research and astrophysics. Quan- titative knowledge of atomic hydrogen negative ion formation cross sections is needed for all the important atmospheric gas species [ 1 ]. The need for collisional information on the production of both neutral hydrogen and its negative ion is of current interest for neutral beam injection into fusion plasma device and in ion source development for high energy accelerators and storage rings. Most experiments concerned with the measurement of single electron capture cross sections for H ÷ [2--4] have been performed at energies below 350 eV. On the other hand few data have been accu- mulated on H+-Kr collisions in the low keV region [5-10]. Measurements of o1_1 have been reported by Williams [9] in the energy range 2.0 to 50.0 keV, by Fogel' et al. [ 11 ] at energies between 3.0 and 65.0 keV