NEGATIVE-ION FORMATION IN COMPOUNDS RELEVANT TO SF6 DECOMPOSITION IN ELECTRICAL DISCHARGES

Dissociative and nondissociative electron attachment in the electron impact energy range 0-14 eV are reported for SOF2, SOF4, SOF2, SF4, SO2, and SiF4 compounds which can be formed by electrical discharges in SF6. The electron energy dependences of the mass-identified negative ions were determined in a time-of-flight mass spectrometer. The ions studied include F- and SOF2-* from SOF2; SOF3- and F from SOF4; SO2F2-*, SO2F-, F2-, and F- from SO2F2; SF4-* and F- from SF4; O-, SO-, and S- from SO2; and SiF3- and F- from SiF4. Thermochemical data have been determined from the threshold energies of some of the fragment negative ions. Lifetimes of the anions SOF2-*, SO2F2-*, and SF4-* are also reported.