Dissociative electron attachment to the unstable carbon ...

Dissociative electron attachment to CS 5
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0
S -
0 1 2 3 4 5 6 7 8 9
Electron Energy (eV)
Figure 3. S − ion signal from dissociative electron attachment to CS 2 as a function of
electron energy
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(a)
S -
CS -
S 2
-
5 6 7 8 9 10
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1
(b)
S -
CS -
S 2
-
5 6 7 8 9 10
Electron Energy (eV)
Electron Energy (eV)
Figure 4. Dissociative electron attachment to CS 2 between 5 and 10 eV. The same
data are presented with linear (left) and logarithmic (right) vertical axes.
time-of-flight and the electron energy. In plot (b) C − and CS − 2 can be seen very weakly.
The CS − 2 is most likely produced in the interaction region by secondary charge transfer
reactions as reported in [22]. Figures 3 and 4 show integrated signals of the anions
formed. The double peak at 3.6 eV could not be resolved clearly due to the current
experimental electron energy resolution. There is perhaps some hint of the double peak
structure in the data in Figure 3 near 3.6 eV. The centroids of the of the three S − peaks
from CS 2 at 3.5, 6.2 and 7.7 eV were used in the energy calibration of the data. The
differences between positions of the geometric centroids and the peak maxima were less
that 0.15 eV.
3.2. Composition of the gas formed in the microwave plasma and positive mass spectra
The composition of the gas sample formed in the microwave discharge depended strongly
on the inlet pressures of CS 2 and He as shown in Figure 5. Figures 5 shows positive ion