Emission cross sections forN2+(3914 ÅA) forF+,Ne+, andNa+ions incident onN2gas

Absolute cross sections for the emission of the 3914-ÅA radiation of the ${\mathrm{N}}_2^{+}$ first negative system have been measured for ${\mathrm{F}}^{+}$, ${\mathrm{Ne}}^{+}$, and ${\mathrm{Na}}^{+}$ ions incident on a gaseous nitrogen target. The energy range covered was 30 to 100 keV. It is shown that for incident ${\mathrm{F}}^{+}$ and ${\mathrm{Ne}}^{+}$ the emission cross sections closely resemble in shape the corresponding charge-transfer cross sections for these ions with ${\mathrm{N}}_2$. In the case of ${\mathrm{Na}}^{+}$ the two cross sections bear little resemblance. These results are consistent with the magnitudes of the internal-energy change required for each of the processes. It is concluded that charge transfer is the dominant process for exciting the $B{}_{}{}^2{}_{}{}^{}\Sigma (v^{\prime }=0)$ state in the cases of ${\mathrm{F}}^{+}$ and ${\mathrm{Na}}^{+}$, while no such conclusion can be drawn for ${\mathrm{Na}}^{+}$.