A low-energy, electron-spin-polarized helium(+) ion source for use in surface studies

[摘要] A spin polarized He$sp+$ ion source has been developed to study the dynamics of ion-surface interactions. The He$sp+$ ions are produced by Penning ionization in collisions between electron-spin-polarized He(2$sp3$S) metastable atoms contained in a weak rf-excited discharge. The ions are extracted from the discharge and focused onto clean or adsorbate-covered surfaces using a series of electrostatic lenses. The impact energy can be varied from $m{<}10eV$ to $m{ge}650eV$ and typical beam polarizations are 10-15%. Information about ion/surface interactions, and the dependence of those interactions on the incident ion energy, is obtained by measuring the energy distribution and polarization of electrons ejected from the surface as a result of Auger neutralization.

[发布机构] Rice University

[效力级别] matter