Cross Sections for SomeN2andN2+Emissions Induced in anN2Target by 20- to 100-keVH+and H Impact

Abstract

Absolute emission cross sections for nine ${\mathrm{N}}_2^{+}$ first negative bands ($v^{\prime }=0\mathrm{}\to v^{\prime \prime }=0,1,2,3\mathrm{}$, and $v^{\prime }=1\mathrm{}\to v^{\prime \prime }=0,1,2,3,4\mathrm{}$) have been determined under single-collission conditions in the excitation of ground-state ${\mathrm{N}}_2$ molecules by a beam of 20- to 100-keV protons. Emission cross sections for the (0, 0) band of the ${\mathrm{N}}_2^{+}$ first negative system and the (0, 2) band of the ${\mathrm{N}}_2$ second positive system resulting from fast hydrogen-atom impact on ground-state ${\mathrm{N}}_2$ molecules were obtained through the use of a charge-exchange model which predicted the observed variation of emission intensity with ${\mathrm{N}}_2$ pressure. The model also yielded values for the sum of the cross sections for electron capture and loss by fast hydrogenic beam particles traversing ${\mathrm{N}}_2$. An upper limit of 4 × ${10}^{-20\mathrm{}}$ ${\mathrm{cm}}^2$ has been established for the emission cross section of the (0, 2) ${\mathrm{N}}_2$ second positive band resulting from 100-keV proton impact.