Chemistry Reference
In-Depth Information
2.0
Electric field
Cathode
(glass)
1.5
1.0
0.5
Anode
(Glass)
0.0
14
16
18
20
22
24
26
28
Time (ns)
E
/
n
(
Td
)
250
225
200
175
150
125
100
75
2.0
Electric field
Cathode
(glass)
1.5
1.0
0.5
Anode
(Glass)
0.0
14
16
18
20
22
24
26
28
Time (ns)
Log
10
(
n
max
/
n
)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
FIGURE 8.5
Results of [21]: Calculated distributions of electric field and density. Positions
oftheelectrodetips(semisphericalglasselectrodesoftheradiusofcurvature7.5mmwereused,
see [21] for more details) are pointed at the left by the arrows. (From Kozlov, K.V., Dobryakov,
V.V., Monyakin, A.P., Samoilovich, V.G., Shepeliuk, O.S., Wagner, H.-E., Brandenburg, R.,
and Michel, P., Cross-correlation spectroscopy in investigations of filamentary gas discharges
at atmospheric pressure, in Ochkin, V.N., ed.,
Selected Research Papers on Spectroscopy of
Nonequilibrium Plasma at Elevated Pressures
, Vol. 4460, pp. 165-176, Society of photo-
optical Instrumentation Engineers, Bellingham, WA, 2002.)
of the pre-breakdown phase, the maximal light intensity is observed on the anode.
The third phase of the MD is a phase of decay of the light and current pulses.
The authors [21] used their experimental data and the results of their processing
to test the validity of the considered physical models of electrical breakdown in a
BD, in particular the model of accumulation of positive space charge followed by the
cathode-directed streamer (CDS), and the model of accumulation of negative space
charge (NSC). They came to the conclusion that their results provide an unambiguous
experimental evidence in favor of the model NSC. Taking into account the initial
conditions assumed for the model CDS, we may expect this model to describe some
special cases of a BD operation. For example, it can account for the first electrical
