AN APPARATUS FOR MEASURING THE ENERGY LOSS IN ATOMIC AND IONIC COLLISIONS

Differential cross sections for the scattering of atoms and ions are of fundamental interest and they supply information necessary for numerical modeling of problems ranging from fusion reactors to planetary atmospheres. In an inelastic collision some energy is lost to ionization or excitation. Data that distinguishes elastic and inelastic collision processes at low keV energies is scant. The distinction is vital for the matching of theory with data and for modeling some problems such as the Jovian aurora. Several apparatus designs are proposed for modifying the present differential collision cross section instrument to measure doubly-differential cross sections (differential in the solid angle of the scattered particle and the energy lost) and energy loss spectra at low keV energies. A new type of ion source that has significant advantages for time-of-flight experiments is presented.