IMPEDANCE PROPERTIES OF ELECTRON STREAMS 



473 



When the transit angles di and 6^ are very small and when the effect 

 of the space between control grid and anode may be ignored, evaluation 

 of (11) yields the result: 



1 - 



Z = Z, + ry 



where 



4 2wo2 



1 - Ji 



TV 

 6di 



1 - Jc 



2Uni. 



1 - /r 



2un 





Cn = 



d\ 





tOi 



1 - J, 



2Uo2 



(13) 



(14) 



Co is the capacitance in the absence of electrons. 



The input impedance is thus seen to be a series circuit composed of 

 a resistance and a capacitance, i.e. 



where 



Z = p + 



1 



icoC 



J. 



1 - Jc 



7? 



2Uq2 



4 2mo2 ddi 



1 - 





TV 



2Uo2 



1_ 1 1 ^ ~-^'6d[ 



1 - /o 



2Mo2 



(15) 



(16) 



(17) 



In studying the capacitance and resistance as functions of space 

 charge it is evident from (16) and (17) that space charge enters 



.3 



In what follows 



7* T^ ^ T T^ ' 



essentially through the functions -^ — - and ° 



2u( 



6di 



