IONIZATION AVERAGE FREQUENCY IN ANODE SHEATH OF PENNING-TYPE HIGH-VOLTAGE DISCHARGE

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IONIZATION AVERAGE FREQUENCY IN ANODE SHEATH OF PENNING-TYPE HIGH-VOLTAGE

DISCHARGE

N. Kervalishvili, V. Kortkhonjia

To cite this version:

N. Kervalishvili, V. Kortkhonjia. IONIZATION AVERAGE FREQUENCY IN ANODE SHEATH OF

PENNING-TYPE HIGH-VOLTAGE DISCHARGE. Journal de Physique Colloques, 1979, 40 (C7),

pp.C7-111-C7-112. �10.1051/jphyscol:1979755�. �jpa-00219461�

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JOURNAL DE PHYSIQUE CoZloque C7, s u p p l d m e n t a u n 0 7 , Tome 40, J u i Z l e t 1979, w g e C 7 - 111

IONIZATION AVERAGE FREQUENCY IN ANODE SHEATH OF PENNINETYPE HIGH-VOLTAGE DISCHARGE

N.A. Kervalishvili, V.P. Kortkhonjia.

I n s t i t u t e o f P h y s i c s , Academy o f S c i e n c e s o f t h e Georgian SSR, T b i l i s s i , U.S.S.R.

T h e o r e t i c a l anu e x p e r i m e n t a l i n v e s t i - g a t i o n s of p h y s i c a l p r o c e s s e s anC anode s h e a t h s t r u c t u r e i n h i g h v o l t a g e d i s c h a r g e i n c r o s s e c 31 H f i e l d s o f t e n r e q u i r e know- l e d g e of i o n i z a t i o n f r e q u t n c y dependence on anode s h e a t h p a r a m e t e r s . g e c e n t l y , t h e r e i s a l a c k of s u c h d a t a . The aim of t h i s work .tias t o measure t h e dependence of i o - n i z a t i o n a v e r a g e f r e q u e n c y on e l e c t r i c f i e l d s t r e n g t h i n anode s h e a t h .

I n t h e "vacuum regime" i n anode s h e a t h a c o n u i t i o n

H i

-cc .'Me i s f u l f i l l e d . The t o t a l i o n c u r r e n t when t h e anode s h e a t h t h i c k n e s s d < l ? P 7 # ~ deterlrrined by t h e ex- p r e s s i o n _7,

zd

eu7*

;3i E,

J i =Pse!.Jqn,.rd.c = 7

'9

n i n g c e l l i n anode s h e a t h a t t h e anode s u r f a c e .

On Fig.1

yo

v e r s u s d i s c h a r g e v o l t a g e a n c liiagnetic f i t l d dependznce i n a a g n e t r o n geometry ('7,=3.2 CC,,

e9

^='i^cm,^7,

⁼

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=2.10-~fo~t, t h e viorking g a s i s A 7

1,

t h e c o n d i t i o n s of srlode adjustaiiznt

[21

a r e m a i n t a i n e a . l n e measurement scheme i s g i v e n i n

[I] ,

I o n c u r r e n t

g i

i s a b o u t 1.5 t i m e s &re- s t e r t h a n o i s c h a r g c c u r r e n t [ a ] and h a s b e e r msusured c l i r e c t l y d u r i n g t h e e x p e r i - :cer~t

. -

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i s shown on t h e Z i p . 2. L s i t i s s e e n ,

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changes a;iproxima- t c l y a s s q u a r e r o o t of d i s c h a r g e v o l t a g e . S i n c e v a l u e s

-

f o r c l i f f e r e n t

j-1

Hence, i o n i z a t i o n a v e r a g e f r e q u e n c y and

(fol

a r e p l o t t e d on t h e f i g u r e , i t

- ie:d(&) - ^{2 ~ 1 ;}

⁽¹⁾ i s p o s s i b l e t o assume, t h a t

- ^9;

^{i s}^pro-

% = - -

7,

E a

~ c J ~ E Q

p o r t i o n a l t o t h e s k u a r e r o o t of g o t e n t i a l E l e c t r i c f i e l d s t r e n g t h a t t h e anode in anode sheath.

c a n be d e t e r m i n e d b y f r e q u e n c y of r o t a t i -

- _Eac

P i g . 3 i l l u s t ~ a t e s

?)i

v e r s u s

-

o n a l o s c i l l a t i o n s

f,,

dependence. F o r h i g h mugnetic f i e l d s ,

^H

s t r e n g t h . It i s always p o s s i b l e t o s e l e c t s u c h

As it is in

['I

⁹ ^a dependence

$i

2

,

a t ivhich

.

^{c a l -}

mode of r o t a t i o n a l o s c i L l a t i o n s always

c u l a t e d b y ( 3 ) , c o i n c i d e s w i t h a measured e x i s t s i n magnetron geometry and i n Pen-

one. L.G. i n [ 3 ] a n e x p r e s s i o n

9

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1979755

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2 J z

3i

= Gim

^{W e o}

A +

Z!

Weo

h a s b e e n u s e d f o r $.

. ^Ne

e l e c t r o n

t

energy.

If we assume, t h a t

Te

<<We, t h e n

we - ^CLe_

^&² ^anciwe911 g e t

e

t.12

-

S u b s t i t u t i n g

-

- _Eo

-

(4) i n t o ( 3 ) , wey 11 f i n a

3; = J;, ~ ~ e d i + E : ) ^Ea

P h i s dependence f o r )'im '1.6

h,

and W , ~ = ~ O O ~ Y ~ ~ ] ~ S p l a t t e d on the F i g . 3 w i t h s o l i d l i n e and i t c o i n c i d e s s a t i s f a c t o r i l y w i t h t h e e x p e r i m e n t a l r e s u l t s .

F i g . 3

1. ig.A.Kervalishvili, V.P.Kortkhonjia, X I 1 I C P I G , p a r t I, Lindhoven, t h e i i e t h e r l a n d s , August 18-22, 1975, p.112.

2. B . B . K e r v a l i s h v i l i 'and ii.P.Kortkhonjia, JIP,

43,

1905, 1973.

3. ¹⁴.A . k ; e r v a l i s h v i l i , V.k".Rortkhonjia, X I 1 1 I C P I G , p a r t 11, GD2, B e r l i n , September 12-17, 1977, p.681.