Single electron detachment of carbon group and oxygen group elements incident on helium

The absolute single electron detachment (SED) cross sections of carbon group elements C−, Si−, Ge− in the energy range of 0.05–0.29 a.u. (5 keV–30 keV) and oxygen group elements O− and S− 0.08–0.27 a.u. (5 keV–30 keV), incident on helium are measured with growth rate method. In our energy region, the SED cross sections of C−, Si−, S− and Ge− increase with the projectiles velocity, at the same time, O− cross sections reach a conspicuous maximum at 0.18 a.u. Some abnormal behavior occurs in measurement of SED cross sections for the oxygen group collision with helium. Our results have been compared with a previous work.