Secondary emission of alkali halide crystals under bombardment of Ar+-Ar5+ and Kr+-Kr5+ multicharged ions

Ion-electron and ion-ion emission of alkali-halogen crystals under bombarding by multicharged Ar+-Ar5+ and Kr+-Kr5+ ions has been experimentally investigated in the 100-1000 eV energy range. The multicharged ions have been produced by a magnetron type source with gas ionisation by an electron impact. The emission from LiF, NaCl, KCl single crystal surfaces has been studied. The experiments show that the variation of the ion-electron emission coefficient with increasing charge and energy of incident ions differs for the crystals under investigation. May be this variation can be accounted for the difference in the width of the crystal forbidden band. The results are approximately the same for both types of incident ions. The coefficients of positive and negative ion-ion emission increase with the charge of Ar and Kr incident ions. The emission from the dielectrics under investigation has been compared with that from metals. A conclusion has been drawn that the emission of negative and positive ions is caused by cathode sputtering target itself