PRODUCTION OF ELECTRONICALLY EXCITED N-2(+) IONS BY ELECTRON-IMPACT ON N-2 MOLECULES

Measurements of the optical emission cross sections for the N-2(+) D-2 Pi(g) --> A (2) Pi(u), emission bands produced by electron impact on N-2 are reported. From these optical data, estimates of the apparent cross sections for the electron-impact production of N-2(+) (D 2 Pi(g)) in the vibrational states v = 4, 7, and 9 are obtained. Combining these data with similar cross sections for the A (2) Pi(g) --> X (2) Sigma(g)(+) and B (2) Sigma(u)(+) --> X (2) Sigma(g)(+) bands and with ionization cross sections of N-2 enables us to analyze the systematics of the cross sections for producing N-2(+) in the X (2) Sigma(g)(+), A (2) Pi(u), B (2) Sigma(u)(+), and D (2) Pi(g) states. Two different kinds of excitation behaviors are found and are discussed in reference to the electronic structure of the N-2(+) ion.