Measurement of One- and Two-Electron-Loss Cross Sections forHe−Ions inH2, He, and Ne Gases (400-1500 keV)

The destruction of ${\mathrm{He}}^{-}$ ions during passage through ${\mathrm{H}}_2$, He, and Ne gas targets has been studied in the range of impact energies 400-1500 keV. ${\mathrm{He}}^{-}$ ions were formed by the charge exchange of positive ${\mathrm{He}}^{+}$ ions. The cross sections for the loss of one (${\sigma }_{-10\mathrm{}}$) and two (${\sigma }_{-11\mathrm{}}$) electrons were determined from the rate of growth of the fast collision products ${\mathrm{He}}^0$ and ${\mathrm{He}}^{+}$ with increasing target gas density.