THE RATIO OF LATERAL DIFFUSION COEFFICIENT TO MOBILITY FOR ELECTRONS IN OXYGEN AND CARBON DIOXIDE

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THE RATIO OF LATERAL DIFFUSION

COEFFICIENT TO MOBILITY FOR ELECTRONS IN OXYGEN AND CARBON DIOXIDE

W. Roznerski, J. Mechlińska-Drewko

To cite this version:

W. Roznerski, J. Mechlińska-Drewko. THE RATIO OF LATERAL DIFFUSION COEFFICIENT TO MOBILITY FOR ELECTRONS IN OXYGEN AND CARBON DIOXIDE. Journal de Physique Colloques, 1979, 40 (C7), pp.C7-149-C7-150. �10.1051/jphyscol:1979773�. �jpa-00219479�

JOURNAL DE PHYSIQUE CoZZoque C7, suppZ6ment au n07, Tome 40, JuiZZet 1979, page C7- 149

THE RATIO OF LATERAL DFFUSION COEFFICIENT TO MOBILITY FORELECTRONSINOXYGENANDCARBONDlOMDE

W. Roznerski and J. ~ e c h l i h s k a - ~ r e w k o .

I n s t i t u t e of Physics, TeehnicaZ University o f Marisk, PoZand.

Abstract. The ratio of lateral diffusion rent falling on the central disc of a c~t?fficient to mobility D/p in oxygen and divided anode results immrtdiately from carbon dioxide at ambient temperature has this calculation [2

1.

been determined for the reduced electric field E/N of

67.4

<E/N ,( 392.4 Td and

15.2 ,( E/N ,( 28009 Td respectively.

Method. The present results have been ob- tained by means of Townsend and Huxleyss technique [I]. The solution of the steady state electron transport equation

-

^ele-

ctron density

-

eatisfying the boundary conditions on the surfaces of the cathode and the anode is expressed in the form of

To consider the influence of negative ions in the presence of attachment pro- cesses,the procedure elaborated by Huxley

as been used in this and Crompton

[I]

h'

work. This procedure adopted to Dhe pre- sent version of experiment has been des- cribed earlier

f

31.

For the determination of the D/p coeffi- cients by means of procedures mentioned above,the knowledge of the DL/p coeffi- an aeries Of dip01e as cient,the attachment coefficient 1) and

c o o

n =

Z

<3(~-2k~)(fck+I)*P(~L2-p.ck)

-

the ionization coefficient o( is neces-

k . ^-4 saq. Except for the

~b

coefficient in

where

' $ . W .

carbon dioxide above 182 Td, the remaining

.rK=

E Z - ~ G A ~ + ^,)Lt _D ^$J _htm2

quantities are available over the inve-

pi ^{,,[4+ &')4;} a Z 7 - @ .

I etigatea-range~efs/N [6,~9-)-131. The L

limits of the variation of the DL-coeffi- The quantities D,DL,W,h,

2

and o( are

the lateral diffusion coefficient,the cient have been estimated on the basis longitudinal diffusion coefficient,the of the thermodynamic treatment of aniso- drift velocity,the length of diefusion tropic diffusion in an electric field

143.

Experiment. The eiperimental conditiens space,the attachment and the ionieation

coefficients respectively. have been described in work [ 5 ] .

The electron current collected by the Results. The ratio of lateral diffusion arbitrary part of the anode may be deter- coefficient to mobility D/p as a function mined by the integration of current den- of E/N in oxygen and carbon dioxide have sitg on the anode over this surface. An been illustrated in the figures 1 and 2 expression for the fraction of total cur- respectively.

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1979773

The estimated values of the standard de-

r121 M.S.Bhalla and J.D,Cra~gs. Proc.

L J -- -

vation of D/p coefficients ara equal

Phys.Soc.S.369 (1960).

1.5% for E/N

>

^{182 Td in} carbon dioxide

r

131 S.R.Alger and J,A.Rees, J.Phys.D:

L J ^-

and 1% for all other values of E/N in

Appl .Phys.2,2661 (1 976).

oxygen and carbon dioxide.

Conolusion. 1% seems,that the procedure applied in the present work allows to determine the D/p coefficients for the large range of reduced electric field.

References.

[l

]

L.G.H.Hwrleg and R.W.Crompton, The Diffusion and Drift of Electron8

fn<

Gases, Wiley-Interacience ,New York 1974.

[

21 W.Roznerski, J.Phya.D: Appl .Phys, ll,L 197 (1978).

-

[ ³ ]

W .Roenerski and J.Mechli6ska-Drewko , Phys.Letters A (accepted for publi- cation).

[ ⁴ ]

R.E.Robson, Aust. J.Phys.25,685

(

1972)

[

⁵

]

^W .Roznerski and J.Mechlidska-Drewka, Report Z.N.P.G. (~echnical Universi- ty of ~dadsk)- Fizgka I&.-, 105

(1977)

[6] J.J.Lowke and J.H.Parke2, Phys.Rev.

181,302 (1969).

[ ⁷¹ -

^M.S.Maidu and A.N.Prasad, J.Phys.Ds

Appl .Phys .2,957

(

^1970).

[

⁸¹ J.A.Rt$es. Aust.J.Phys.j1,462

(

¹⁹⁶⁴⁾

[

91 C.S.L&shminarasimha, J-Lucas and

N.Kontoleon, J.Phys,D: Appl.Phys.

7,2545 (1974).

-

[lo] H.SchlumboJm, Z.Physlk5=,492

f

1965).

[I

l] J.B.Pree1y and L.H.Pisher, Phga.

Rev.=, A304

(

^1964).

Gb0(vcm' tori')

[

^{20 40 6 8 I 1 l?,}

Fig. 1 oTb@i%coeff icient in oxygen as a function of E/N, 0 Present results;

A

Lowke and ~arker[6];

V Naidu 'and Praaad- [7].

V~ ( v cm' tor31

0 20 40 60 80 100

5 v

Fig.2. The D/p values in carbon dioxide as a function of E/M. Present resulta; 0 ,Results of work [3] 8

Laksbminarasimha et 81. [9] ;

A

Lowke and Parker [ 6 ] ; Rees [8]

.