Mass spectrometric investigation of material sputtered under swift heavy ion bombardment

摘要: Abstract The flux of particles emitted from a solid surface under electronic sputtering conditions induced by irradiation with Swift Heavy Ions (SHI) was investigated using time-of-flight mass spectrometry in connection laser post-ionization. While secondary ions the irradiated were directly detected reflectron ToF spectrometer, corresponding neutral post-ionized after their emission single photon ionization pulsed VUV beam. spectrometer operated delayed extraction mode, thereby ensuring that and neutrals otherwise identical experimental conditions. For comparison purely nuclear process, spectra taken 4.8 MeV/u 197Au26+ 48Ca10+ compared to those measured situ bombardment 5 keV Ar+ ions. Most importantly, we find most cases vast majority sputtered material is state, mainly consisting atoms small (mostly diatomic) clusters. metallic targets, significant effect for In Bi, while other metals like Mo or Ag do not appear sputter very efficiently SHI irradiation. As an example semiconductor target, (amorphous) Ge found exhibit large yield Au projectiles, practically no observed Ca ions, clearly indicating stopping power threshold this material. KBr as ionic crystal exhibits expected yield, atomic species K2Br We about equal signals ionized K clusters, exclusively molecule. Besides these major species, progression [KBr]nK+ – much smaller intensity [KBr]nBr− which similar size distribution others [LiF]nLi+ clusters LiF. Interestingly, negative halogen are irradiation, they positive alkali