Environmental Engineering Reference
In-Depth Information
Ta b l e 3 . 3
The typical specific photon flux of resonant radiation in vapors of alkali metals and the
specific typical flux of the radiation intensity.
I
0
/
N
0
,10
17
Wcm
Vapor
j
0
/
N
0
, 100 cm/s
Li(2
2
P
)
2.3
6.8
Na(3
2
P
1/2
) .6
9
Na(3
2
P
3/2
) .4
5
K(4
2
P
1/2
)
4.5
15
K(4
2
P
3/2
)
3.6
9.4
Rb(5
2
P
1/2
) .9
0
Rb(5
2
P
1/2
) .2
.0
Cs(6
2
P
1/2
) .3
.6
Cs(6
2
P
3/2
) .7
.6
Figure 3.14
The relative excitation temperature
T
for for resonantly excited atoms versus the
radiation flux according to (3.107).
1.44
j
0
, that is, for alkali metal vapors the number density of reso-
nantly excited atoms exceeds that of ground state atoms by 1.5 times at this photon
flux.
We now consider the character of penetration of the flux of resonant radiation in-
side a plasma. Accounting for the processes of absorption and stimulated emission
for resonant photons, we have the balance equation for the flux
j
ω
(
z
) for resonant
photons propagating in a plasma:
„
ω
at
j
ω
D
dj
ω
dz
D
j
ω
σ
0
ω
N
D
j
ω
σ
ω
N
0
C
j
ω
k
ω
,