attributed to a shunt conductance such that niiijdo av/ airii moi^ fanA 



Also, in tHis<:^^^ l4^|4s slnicly^-^, jthe m<>dui4lii)i(i"<?x)etfficient. Hence, the 

 conductariredWtb action of tlielongitiid'in^i'fitlds is, from (hl8), simply 



2 ?i -•->- ' 



(h43) 



4Fo ^7 



And, due to the action of transverse fields there is another conductance, 

 from (h41) 



'470^7 \7' 

 G = Gi + Go 



y^ W / 



(h44) 

 (MS) 



These are surprisingly simple and very useful relations. 



It is interesting to take an example which will indicate both effects. 

 We have from (b24) for tubes of radius ro with a narrow gap between them 



f^: = ^;[l - /I(7ro)//o(7'-o)]. (h46) 



Accordingly, the part of the conductance due to the longitudinal field is 



G, = Fz.(7^o)/o/4Fo (h47) 



Fdyro) = -yd^l/dy 



(h48) 



IjMV _ (h(yro)\ _ (hiyro)y- 

 Myro)/ ^ " V/o(7ro)/ Voiyro)/ _ " 



= -2 



Similarly, the part of the conductance due to the transverse field is 



Gt = FTiyro)Io/'iVo 



Friyro) = -yT~~i 

 dy To 



1 p/1 d ' 



■iL[\yJr^: 



2rdr. 



From (bl6) we obtain 



^r = Ioiyr)/Io(yro) 



■si. [;ar^') 



hiyrp) _ ll{yro) ~\ 

 hiyro) ll(yro)j 



" 'T' = hiyr)/ hiyro) _ 

 7 dr To 



2r dr 



(h49) 

 (h50) 



(hSl) 

 (h52) 



