ELECTRON BALLISTICS IN HIGH-FREQUENCY FIELDS 335 



1,0 



0.8 



^ 



0.6 



0.4 



0.2 



0.0 



10 



14 



e IN RADIANS 



Fig. 2 — The (velocity) modulation coefficient between an initially uniform electron stream 

 and a uniform electromagnetic field as a function of transit angle. 



HEIL & HEIL 1935 



vo^ 



CATHODE 3 



-''■'''''''■ •^^~ 



CONVERSION 

 REGION 



T 



^ 



COLLECTOR 



HAHN & METCALF 1939 



CONVERSION 

 REGION 



1^ 



Ji p iiT 



CATHODE 



COLLECTOR 



VARIAN & VARIAN 1939 





CONVERSION 

 REGION 



CATHODE COLLECTOR 



Fig. 3 — Typical velocity variation devices employing transit-time bunching. 



