ON DETERMINATION OF TL, IN, NA NORMAL ATOM CONCENTRATION BY RESONANCE LINES BROADENED WITH MERCURY PRESSURE

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ON DETERMINATION OF TL, IN, NA NORMAL ATOM CONCENTRATION BY RESONANCE LINES

BROADENED WITH MERCURY PRESSURE

V. Vdovin, N. Vdovina

To cite this version:

V. Vdovin, N. Vdovina. ON DETERMINATION OF TL, IN, NA NORMAL ATOM CONCEN- TRATION BY RESONANCE LINES BROADENED WITH MERCURY PRESSURE. Journal de Physique Colloques, 1979, 40 (C7), pp.C7-839-C7-840. �10.1051/jphyscol:19797405�. �jpa-00219405�

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JOURNAL DE PHYSIQiIE CoZZoque C7, suppZdment au n07, Tome 40, JuiZZet 2979, page C7- 839

ON DETERMINATION OF TL, IN, NA NORMAL ATOM CONCENTRATION BY RESONANCE LINES BROADENED WITH MERCURY PRESSURE

V.G. Vdovin and N.A. Vdovina.

AZZ-Union I n s t i t u t e o f L i g h t Sources, Saransk, U.S. S. R.

To e s t i m a t e t h e r a d i a t i o n while deve- Analogously one can have:

l o p i n g t h e l i g h t sources w i t h metal haloge _{Z > o} n i d e a d d i t i v e s it is necessary t o know

t h e a d a i t i v e atom c o n c e n t r a t i o n In t h e discharge and reasonably p r e c i s e a e s c r i p - t i o n o f resonance line contour shapes.

There were suggested some meshods f o r ae- termination of a a d i t i v e c o n c e n t r a t i o n u0(r): by absorbtion i n the wing /I/, ~y s e r r - r e v e r s e d p a r t of r a d i a t i o n contour /2/ and by f u l l absorption i n l i n e AG /3/.

Each is based on knowledge o f resonance l i n e contour shape i n o p t i c a l l y t h i n la- y e r P(v,r) i n t h e source. However t h e experimental determination P(v) i s r a t h e r d i f f i c u l t , t h e r e f o r e i t s e s t i m a t i n g form is used which w a s obtained i n v a r i o u s as- sumptions t o t y p e s o f b r o a d e r i n g i n t e r - a c t i o n . The agreement betvreen t h e estima- t e d P(v) and r e a l v a l u e s is e v a l u a t e d i n t h i s c a s e n o t d e r e c t l y by Chat how e x a c t l y t h e e s t i m a t e d d i s t r i b u t i o n o f l i n e inten- s i t u i n r a d i a t i o n I(v,x) and absorption F(v,x) corresponds t o t h e observed one i n t h e source. In t h i s work such a check is performed under c o n d i t i o n s o f non-homoge- neous d i s t r i b u t i o n of absorbing and r a d i a - t i n g atoms and a l s o t h e broadening compo- n e n t Hg that makes t h e s u b j e c t complicated.

The above mentioned methods o f no determination a r e common f o r Doppler and Lorente P(v) shapes. However P(v) o f resonance l i n e s , broadened by f o r e i g n g a s , ha- v e r a t h e r more comlicated form /4/. For

where z = v-vo

-

frequency, r e a d i n g from t h e c e n t r e of u n s h i f t e d l i n e ,

-

^norma-

l i z a t i o n f a c t o r f o r contour i n z = 0, AC6- t h e d i f f e r e n c e i n f o r c e c o n s t a n t s o f Van d e r Waals p o t e n t i a l f o r upper and lower t r a n s i t i o n l e v e l s , N

-

mercury atom concen-

4 r 3

^bC6

t r a t i o n , z : : t, K

,

^. ^-

u2 .

9h

Paper /8/ r e p r e s e n t s Lenard-Johns p o t e n t i - a l ana expresslon f o p contour shape, ob- t a i n e d by p r e s s u r e broadening t h e o r u , de- veloped by Yablonslry / 5 / . I n t h i s c a s e as a n a l y s i s showed, P(v) f o r our c o n d i t i o n s may be l i m i t e d by:

where H

-

number of p a r t i c l e s i n p r a d i u s i n t e r a c t i o n s p h e r e f o r r a d i a t i n g (absor- b i n g ) atom, Po(z)-line contour, when t h e r e

a r e no broadening atoms i n t h e s p h e r e o f i n t e r a c t i o n , PI (s)- l i n e c o n t o u r , when t h e r e is one p a r t i c l e i n t h e sphere o f r a d i u s p

,

P1(z)- a Function o f p o t e n t i a l w e l l depth

6 =

( A '6) and fcequency s h i f t minimum

4ft

bCj2 A '6

a,nC,,-

-

3ipq2 _'_J fi p6

thia c a s e t h e r e suggested some t h e o r i e s S i n c e

the/

i n v e s t i g a t e d d i s c h a r g e is f o r P(v) d e s c r i p t i o n while assuming v a r i - non-uniform according t o r, P(v) can be ous i n t e r a c t i o n poten1;ials /5,6/. For p a i r e s t i m a t e d i n a number o f source l a y e r s , T1-Hg paper /?/ used t h e f o l d of d i s p e r s i v e w i t h t h e contour b e i n g c o n s t a n t . Experimen-

contour w i t h s t a t i s t i c a l one, obtained i n t a l data f o r atom temperature Ta(r) and a s s m p t i o n o f Van d e r Waals p o t e n t i a l . broadening atom d e n s i t y N /9/ were used in

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:19797405

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l a y e r approximation. Absorbing atom con- s e n t r a t i o n a t T1 6 P 2 ²

2 1/2,3/2' In '1/2,3/2

and Na 5 SIl2 l e v e l s have been determined f o r f u l l absorption of AG1 i n t h e b l u e l i n e wings, p r e s e n t e d by t h e d i s p e r s i v e P(v) form. The confidence of t h e obtained con- c e n t r a t i o n v a l u e s w i t h e r r o r +IWO h a s been e v a l u a t e d according t o a d d i t i v e dosage t a k i n g i n t o account t h e complex compound formation and b e s i d e s f o r TI-according t o a b s o r p t i o n i n t h e l i m i t s of molecular band

Ttr x q ~ + - + A 3 n .

I n terms o f temperatura TeXc(r) t h e p o p u l a t i o n s o f T l

7

2 SqI2, I n

"'

1 /2 and Na 42pl /2, j/2 e x c i t e d s t a t e s viere r e c e i v e d by modified B a r t e l s method

/lo/.

I n e s t i m a t i n g P(v) t h e r e used A C6 c a l c u l a t e d by London formula /I1 / and

A CI2 o b t a i n e d From e x p e r i m e n t a l l y measu- r e d s a t e l l i t e p o s i t i o n according t o Hind- marsh theory /4J

.

While modelling t h e ade- quacy o f e s t i m a i t e d I ( v , x ) and F(v,x) con- t o u r w i t h experimental one t h e parameters, d e f i n i n g P(v) i n c l u d i n g c o n s t a n t s A C6 and b. CI2 were n o t i c e d t o vary.

E s t i m a t i o n s performed w i t h employing /I/ and /2/ showed t h a t a

a ) observed a b s o r p t i o n contour F(v,x) a r e s a t i s f a c t o r a l y d e s c r i b e d i n Van d e r Waals i n t e r a c t i o n s o T1, I n atom concent- r a t i o n s found by fill a b s o r p t i o n AG w i t h an e r r o r o f n o t more than 2% and Na- n o t more than 1% d i f f e r Xrom experimentally d e f i n e d by absorption in b l u e wing and a l s o a r e m good agreement w i t h chemical a n a l u s e s o f r i l ~ i n g composition m p a r t l - c u ~ a r , I o r T I 1 molecula number, rormect i n TI atom recombmation d u r i n g plasma decompo s r t i o n ;

b ) t h e usage of Lenard-Johns poten- t i a l i n P(v) d e s c r i p t i o n does n o t make s i g n i f i c a n t refinement i n v a l u e s f o r a d d i t i v e atom c o n c e n t r a t i o n

,

though improves t h e form aaequasy o f e s t i m a t e d P(v,x) and I(v,x) w i t h experimental ones b o t h i n b l u e and r e d l i n e wings ;

c ) f o r more e x a c t d e s c r i p t i o n of P(v) i n wide i n t e r v a l A v probably it is needed t o u s e a n o t h e r type o f quasi-mole- c u l e p o t e n t i a l

Y(p)=

^{where n}^f^{6 ,}

P"

and 1 2 ^;

d) s h a r p d i f f e r e n c e of wing inten- sity i n l i n e s T1 377 and I n 410 nm is explained by superposing t h e e l e c t r o n i c system o f i o d i d e a b s o r p t i o n bands

X"Z*+

- t A 3 L '

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