Knowledge Bank

Absolute collision cross sections and generalized oscillator strengths have been determined for several transitions in $N2$ and CO at 300, 400 and 500 eV electron kinetic energy and small scattering angles. Two of these transitions a $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma g+\leftarrow X1\Sigma g+$ in $N2$ and $B1\Sigma +\leftarrow X1\Sigma +$ exhibit large deviations from the behavior predicted by the Born approximation. These deviations have been observed for transitions which have the same term symbol in ground and excited states.