SECONDARY-ION ENHANCEMENT IN SLOW HIGHLY-CHARGED HEAVY-ION BOMBARDMENT

Carbon thin film was bombarded with high charge state Xeq+ ions, and t he secondary carbon yields were measured as a function of charge state in the broad range of q = 8 to 44 at the kinetic energy of 1.0 MeV an d, also, q = 44 at 175 keV. It is found that the secondary ion yields per incident ion increase with increasing q; the increase rate is rema rkably high in q > 26 with the rate of q(8.5) and rather moderate in q > 31. The yield and spectra of the secondary ions are not very differ ent for 1.0 MeV and 175 keV for Xeq+ (q = 44) ion incidence.