Electron-stimulated Desorption of Kr²⁺ Ions from the Surface of Solid Kr

抄録

When low-energy electrons or photons (10-1000 eV) impinge on a surface of a rare-gas solid (RGS), desorption of ions, neutrals, and molecules can occur together with other processes. The desorption is due to an initial electronic excitation and a subsequent transformation of the excitation energy into kinetic energy of a desorbed atom. This phenomenon is called DIET (desorption induced by electronic transitions) : DIET by electron impact and photon impact are well known as ESD (electron-stimulated desorption) and PSD (photonstimulated desorption), respectively. Few studies of DIET of ions from RGS have been reported. In the investigation of ESD of H₂ physisorbed on condensed Xe, Arakawa and Tuzi found that ESD of ions (Xe⁺, Xe²⁺) and neutrals from condensed Xe could occur. Sakurai et al. reported the PSD of ions from the surface of solid Ar, Kr, and Xe. Dujardin et al. reported that electronically excited ions (Ar^+*) and doubly charged ions (Ar²⁺) might be primary excited states which lead to desorption of Ar⁺ from solid Ar. Menzel reported that the desorption of singly and doubly charged Kr ions occurs due to core ionization. They suggested that the kinetic energy of a desorbed ion was caused by Coulomb repulsion between adjacent ions which were formed by charge exchange between an initial multiply excited atom and its ground-state neighbor or by the deexcitation of doubly charged ionic dimers.