Single and Double Electron Loss Cross Section for 2-50-keVH1−Ions Incident upon Hydrogen and the Inert Gases

Direct determinations of the cross sections for single and double electron loss in single collisions by 2-50-keV ${\mathrm{H}}_1^{-}$ ions incident upon hydrogen molecules and inert-gas atoms are made by the method of measuring the rate of growth of the fast-collision products, ${\mathrm{H}}_1^0$ and ${\mathrm{H}}_1^{+}$, with increasing target-gas number density. Previous measurements of ${\sigma }_{-1,0\mathrm{}}$ have included contributions from ${\sigma }_{-1,1\mathrm{}}$. It is shown that allowance for such contributions is only partially successful in improving the agreement between previously published values.