Geoscience Reference
In-Depth Information
6.6
UV Spectra Obtained in a Longitudinal Plasmoid
in Free High-Speed Swirl Flow
Recall that Kapitsa measured an intensive UV radiation and soft X-ray radiation
(in the range 10
2
-10
3
eV) generated by a longitudinal MW plasmoid in swirl flow
in his work many years ago. He named this phenomenon the “UV-catastrophe”
inside the longitudinal vortex plasmoid. The UV spectra (
D
270-340 nm) of
the longitudinal vortex plasmoid created by the capacity-coupled high-frequency
discharge in swirl flow were recorded and analyzed in his work. The typical UV
spectra of this longitudinal vortex plasmoid in free swirl flow recorded by the
optical spectrometer AvaSpec 2048 are shown in Fig.
6.7
. It was revealed that the
intensity
I
of the optical lines and the optical bands in the wave range 250-300 nm is
considerably increased in the constricted or filamented longitudinal vortex plasmoid
(compared with the diffuse high-frequency discharge plasma in non-swirl flow in
the same conditions). The value
I
was increased up to a factor of 10-20 during the
transition from a filamentary (corona) high frequency discharge to the longitudinal
high-frequency plasmoid (Fig.
6.7
). This value
I
depends also on a duty cycle. So,
this phenomenon depends on a plasma formation overheating (the average high-
frequency power input in the plasma) (Fig.
6.8
). UV radiation is increased in the
Black- P
HF
=100W
Red- P
HF
=200W
12
10
8
6
4
2
0
260
280
300
320
340
360
380
400
λ
, nm
Fig. 6.7
UV optical spectra obtained in the longitudinal high-frequency plasmoid in free swirl
flow.
P
st
1bar;
V
t
V
ax
30 m/s
