The measurement of angular differential cross sections at the SSL Atomic Scattering Facility

The design of the SSL Atomic Scattering Facility (ASF) located at the NASA/Marshall Space Flight Center as well as some of the initial experiments to be performed with it, are covered. The goal is to develop an apparatus capable of measuring angular differential cross sections (ADCS) for the scattering of 2 to 14 eV atomic oxygen from various gaseous targets. At present little is known about atomic oxygen scattering with kinetic energies of a few eV. This apparatus is designed to increase the understanding of collisions in this energy region. Atomic oxygen scattering processes are of vital interest to NASA because the space shuttle as well as other low earth orbit satellites will be subjected to a flux of 5 eV atomic oxygen on the ram surfaces while in orbit. The primary experiments will involve the measurements of ADCS for atomic oxygen scattering from gaseous targets (in particular, molecular nitrogen). These, as well as the related initial experiments involving thermal He scattering from N2 and O2 targets will be described