Low-energy ion beam system for materials studies

An ion accelerator system has been developed for the measurement of low-energy, hydrogen isotope sputter yields. This system provides well-characterized, mass-analyzed beams of hydrogen isotopes at low ion energies and high current densities. The system delivers these beams into an ultrahigh vacuum chamber equipped with a cylindrical mirror analyzer for in situ Auger electron spectroscopy measurements on samples after hydrogen isotope exposure, and a quadrupole mass analyzer for secondary ion mass spectroscopy measurements during hydrogen isotope bombardment. Ion energies range from 300 eV to 10 keV at flux densities of up to 3.6 x 1016 atoms/cm2 s over a 6-mm diam spot. The performance characteristics and analytical capabilities of the system are described. Representative sputtering data for Si by deuterium are given and other brief surface studies are described