Attenuation and single electron charge-exchange cross sections of He+ on He in the energy range 500–5000 eV

Abstract

A He+(1s), monoenergetic ion beam was used to bombard He gas in a dual purpose scattering chamber. The total charge-exchange cross section was measured using the parallel plate collection method for low energy target ions, while a lower bound to the total cross section was obtained via a beam attenuation measurement. Both cross sections decreased with increasing incident ion beam energy, but they did not coincide until approximately 2500 eV. Similar cross sections obtained in previous measurements suggested a much closer correspondence between these two cross sections and thus a near-zero non-charge-exchange cross section at much lower energies. Further comparison of the present charge-exchange data with both experiment and theory is also displayed, and relatively good agreement is observed.