ELECTRON-IMPACT EXCITATION OF THE CHI-1-SIGMA-G-,Y1-PI-G, AND OMICRON-31-PI-U RYDBERG ELECTRONIC STATES OF THE NITROGEN MOLECULE

Electron-impact excitation of the x g-1, y g1, and o3 u1 Rydberg electronic states of the nitrogen molecule has been studied. We have measured the maximum electron-impact optical-emission cross sections of many vibrational bands of the y g1w u1, y g1a u-1, and x g-1a u-1 electronic transitions. The maximum values of the optical-emission cross sections of these band systems are typically less than or on the order of 10-20 cm2. The dependence of the emission cross sections of selected bands on electron energy has been studied. The excitation functions of the ya and xa bands have similar shapes below about 50 eV with a peak near 32 eV, and are approximately proportional to 1/E at high energies. We have measured the emission cross section of the o3 u1a g1(0,0) band as a function of electron energy. The excitation function of the o3a(0,0) band has a broader shape than the excitation functions of the yw, ya, and xa bands. We have calculated Franck-Condon factors for the yw, ya, and xa band systems and compare them with the experimental emission cross sections of these band systems. The apparent electron-impact-excitation cross sections of the vibrational levels of the x and y electronic states are estimated. © 1990 The American Physical Society.