Polarization of the ${\mathrm{H}}_{\alpha }$ Line Produced in ${\mathrm{He}}^{+}$ + ${\mathrm{H}}_2$ Collisions

Van Brunt and Zare have noted that polarized spectral lines might be observed from many types of dissociative collisions which produce excited atomic fragments and that studies of this polarization could prove to be valuable in determining the angular distribution of the fragments. We have observed that such polarization does, indeed, exist in the ${\mathrm{H}}_{\alpha }$ line produced by dissociative charge transfer of ${\mathrm{He}}^{+}$ + ${\mathrm{H}}_2$ collisions. Measurements have been made at 90° to the beam direction in the energy range from 45 to 700 eV.