X-ray emission induced by 60 keV high-flux negative copper ion implantation

X-ray emission induced by high-flux 60 keV negative Cu ion implantation into silica glasses (a-SiO2) has been studied in an energy range of 0.6 – 20 keV. At low ion fluxes, the emission spectrum consists of a strong Cu(L) line at 0.95 keV only, without Cu(K) and Si(K) lines. The result is explained by the electron promotion through the quasi-molecule formation. With increasing the ion flux, new peaks appear at 1.8, 2.5 and 3.2 keV. These peaks are ascribed to the sum-peak effect under high-flux implantation. Judging from the cross-sections and the time dependence, the observed Cu(L) X-ray is concluded to be generated via Cu-O collisions.