Light emissions in the wavelength region 2000-6000 AA produced by dissociative electron impact on CF4, NF3 and SF 6 were studied. A double-onset structure in the cross section of the intense continuous emission from CF4 was found and might be interpreted as evidence that excited CF3+3 fragment ions produced by two different mechanisms rather than CF 4+ parent ions are the emitting species. Comparatively weak fluorine 4p to 3 s line emissions resulting from the total fragmentation of the parent NF3 and SF6 molecules were also observed. In both cases the 2.4D to 4P multiplet at 3669 AA has the largest emission cross section with 4.4+or-1.2*10-20 cm 2 and 12.9+or-3.3*10-20 cm2 from SF 6 and NF3, respectively, at 100 eV. Four F II emissions with comparatively high onset potentials and maximum emission cross sections in the 10-20 cm2 range (at 200 eV) were found in the NF 3 spectrum but not in the SF6 spectrum. The break-up of both SF6 and NF3 leads to a broad unstructured emission between 2000 and 3200 AA which has not yet been identified.
|Number of pages
|Journal of Physics B: Atomic and Molecular Physics
|Published - 1987
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics