Electron attachment rate constants of SO2 and CS2 in Ar, N2, and CH4 at varied E/N

Abstract

The electron attachment rate constants of SO2 and CS2 in the buffer gases of Ar, N2, and CH4 (150 to 530 Torr) at various E/N (1–16 Td) were measured by a parallel-plate drift-tube electron-swarm technique. The electrons were produced by irradiating the cathode with KrF laser photons. For the SO2–Ar mixture, the electron attachment rate constant of SO2 increases with increasing E/N and is independent of Ar pressure. For SO2 in N2 and CH4, the electron attachment rates decrease with increasing E/N and increase with increasing buffer gas pressure. For CS2 in N2 and CH4, the electron attachment rates increase with increasing CS2 and buffer gas pressures and decrease with increasing E/N. The electron attachment to SO2 and CS2 in the buffer gases of N2 and CH4 is a three-body process. The collisional-stabilized rates of ‘‘temporary’’ negative compound ions SO−*2 and CS−*2 by various gases are investigated.