MAGNETIC EFFECTS ON NOISE IN A GERMANIUM FILAMENT 663 



(Note that as ^ — > <x>, this quantity tends to 4aVl5D^, as before in our 

 limiting process.) 



When ^1 = ^2 = ^, 'S and T also simplify somewhat, and the result is 



iy H — -. — 2 — r 



_ + 2T^ + - (^- - r j smh 2 - ^ cosh ^ + -^ smh $ 



•■[(^O'-a 



where now 



s- ^ 









An alternative form is 

 4 



45 





+ ^ ...y Ut^ + coth ^ + 7 - 



2 2 2 coth - 



(16) 



where 



A = l+-coth-, 



a result which correctly tends to (15) sls xp -> ^ . 10 log Nh for various 

 ^ ^ is shown in Fig. 5. 



ACKNOWLEDGMENTS : 



The author gratefully acknowledges the help given by Dr. Shockley, 

 I who suggested the conceptual picture underlying this theory and who 



