Emission cross sections for electron impact on Cl2

We have measured the absolute emission cross section for the Cl-2(+) A (2)Pi(u)-X-2 Pi(g) system for 10-750 eV electrons incident on chlorine molecules. The cross section for the system possesses a broad peak at 100 eV of 2.0x10(-16) cm(2), typical of such ionization processes. At this energy, the A-X cross section is responsible for two-thirds of the total Cl-2(+) production and one-third of the total ionization cross section. We also measured the emission cross section from 7 to 740 eV for the 307 nm system of Cl-2. The energy dependence of the cross section indicates that the excitation is to a Cl-2 (1)Sigma(+)(u) or (1)Pi(u) state with a decay to a repulsive potential.