Ionization cross sections for 10–300-keV/u and electron-capture cross sections for 5–150-keV/uHe2+3ions in gases

Cross sections for production of positive and negative charge for 10–300-keV/u ${\mathrm{He}}^{2+}$ ions on He, Ne, Ar, Kr, ${\mathrm{H}}_2$, ${\mathrm{N}}_2$, CO, ${\mathrm{O}}_2$, ${\mathrm{CH}}_4$, ${\mathrm{N}}_2$O, and ${\mathrm{CO}}_2$ were measured by the transverse-field method. Single- and double-electron-capture cross sections at 5–150 keV/u for the same targets were measured by the method of deflection of different charge-state components of the beam after passing through a known length of target gas. A secondary-emission detector was used to detect the neutral component of the beam. A small least-squares adjustment of the cross sections was made to satisfy the equation ${\sigma }_{+}$=${\sigma }_{\mathrm{-}}$+${\sigma }_{21}$+2${\sigma }_{20}$ which follows from conservation of charge.