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10 -1
10 0
10 1
10 2
10 3
10 4
10 5
10 5
10 4
10 4
Air
Ar
10 3
10 3
10 2
10 2
10 -1
10 0
10 1
10 2
10 3
10 4
p . d E in (Pa . m)
FIGURE 3.34 Breakdown voltage in dependence on p · d E with the Paschen minimum
calculated by (3.282) with γ =
=
·
m) 1 , C 2
=
·
m) 1 )andair
0.05 in Ar ( C 1
9(Pa
135 V(Pa
( C 1 =
11.3(Pa
·
m) 1 , C 2 =
275 V(Pa
·
m) 1 ).
j
=
j eC (
0
) +
j + C (
0
) =
j eC (
0
) +
1
/
γ
·
j eC (
0
)
and anode j
=
j eA (
d E )
, we obtain after
integration over z for the electron and ion current density
γ
j e (
z
) =
j eC ·
exp
(
α
·
z
) =
j
·
γ ·
exp
(
α
·
z
)
1
+
1
.
(3.284)
γ
j + (
z
) =
j
·
γ ·
exp
(
α
·
z
)
+
1
Replacing γ in (3.284) with the breakdown condition (3.279) permits the rearrange-
ment of the current densities
j e (
z
) =
j
·
exp
[
α
(
z
d E ) ]=
e
·
n e ·
b e ·
E
(3.285)
j + (
z
) =
j
·[
1
exp
[
α
(
z
d E ) ]] =
e
·
n + ·
b + ·
E
and the calculation of electron and positive ion density
E
p
1
j
1
b e ·
j
n e (
z
) =
E ·
exp
[
α
(
z
d E ) ]=
C be ·
·
exp
[
α
(
z
d E ) ]
e
·
e
·
E
p
1
j
1
b + ·[
j
n + (
) =
E ·
[
(
d E ) ]] =
C b + ·
·[
[
(
d E ) ]]
(3.286)
z
1
exp
α
z
1
exp
α
z
·
·
e
e
with 0
z
d E and b
·
p
=
C b =
const . in the discharge gap, see Figure 3.35.
 
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