Ionization in collisions of fast H⁺and He²⁺ions with Fe and Cu atoms

Abstract

A crossed-beam technique, where the collision products have been selected by time-of-flight (TOF) spectroscopy with either a pulsed beam or coincidence counting, has been used to study pure ionization of Fe and Cu by 70-1440 keV amu-1 H+ and 35-425 keV amu-1 He2+ ions. Cross sections for the formation of q times ionized Fe and Cu products by pure ionization have been determined for q=1-4. A comparison with the corresponding (previously measured) cross sections for transfer ionization shows that, in the energy range considered, Fe+ and Cu+ ions arise predominantly through pure ionization. However, for q>or=2, contributions from both transfer ionization and pure ionization are important. Pure ionization becomes dominant at energies which increase as q increases. Measured cross sections for pure ionization have been successfully fitted to values based on an independent electron model approximation.

Study of Alpha Particle Impact Double Ionization Cross Sections of Cu Atom

“…The calculated results of DICS along with experimental observations [33] have been shown in Table 1 and Fig. 1.…”

He2+ impact single ionization cross sections of Cu atom

“…We have considered contributions only from 4s, 3d and 3p subshells as inner shells have negligible effect. Theoretical investigation of direct single ionization has been carried out in the energy range of 35 keV/amu to 425 keV/amu (Patton et al [26]) using BEA. We compared the theoretical result of SICS with the experimental data of single ionization cross sections for corresponding impact energy.…”

He2+ Impact Single Ionization Cross Sections of Fe Atom

“…1. The total theoretically calculated SICS for energy range 35 to 360 keV/amu has been compared to the corresponding experimental data (Patton et al [22]). The contribution of 4s shell is high in threshold range and decreases with increase of impact energy.…”