SHOT NOISE IN DIODES 619 



cathode to the plate. The advantage of the method of average veloci- 

 ties used in this paper is that the effect of transit time in both the 

 thermal tube noise and the shot noise may be found. 



It is noteworthy that Ballantine in 1928 derived an expression for 

 the effect of transit time upon the pure shot noise which is identical 

 to that obtained in this paper.^ 



In conclusion, the writer wishes to express his appreciation to F. B. 

 Llewellyn whose supervision and numerous suggestions made possible 

 this paper. 



References 



1. F. B. Llewellyn, "A Study of Noise in Vacuum Tubes and Attached Circuits," 



Proc. /.i?.£., vol. 18, pp. 243-265 (1930). 



2. G. L. Pearson, "Shot Effect and Thermal Agitation in a Space Charge Limited 



Current," Physics, vol. 6, pp. 6-9 (1935). 



3. W. Schottky and E. Spenke, "Die Raumladungsschwachung des Schroteffektes," 



WissetischaflHche Veroff tntlichungen aus den Siemens-Werken, vol. 16, pp. 1-41, 

 Aug. 6, 1937. 



4. E. Spenke, "Die Frequenzabhangigkiet der Schroteffektes," Wissenschaftliche 



Veroffentlichungen aus den Siemens-Werken, vol. 16, pp. 127-136, Oct. 8, 

 1937. 



5. L. H. Germer, "Distribution of Initial Velocities Among Thermonic Electrons," 



Phys. Rev., vol. 25, 795 (1925). 



6. T. C. Fry, "Thermonic Current Between Parallel Plane Electrodes," Phys. Rev., 



vol. 17, 441 (1921). 



7. L Langmuir, "Effect of Space Charge and Initial Velocities," Phys. Rev., vol. 21, 



419 (1923). 



8. F. B. Llewellyn, "Operation of Ultra High Frequency Vacuum Tubes," B.S.T.J., 



Oct. 1935. 



9. S. Ballantine, " Schrot-Effect in High Frequency Circuits," J.F.I., vol. 206, 159 



(Aug. 1928). 

 10. T. C. Fry, "The Theory of the Schroteffekt," J.F.I., vol. 199, No. 2 (Feb. 1925). 



