452 



BELL SYSTEM TECHNICAL JOURNAL 





-0.8 



1.42 1.44 1.46 1.48 1.50 1.52 1.54 1.56 1.58 1.60 1.62 



7b 



3 

 — ) 

 \ 



4.00 4.02 4.04 4.06 4.08 



4.10 



yb 



4.12 4.14 4.16 4.18 4.20 



Fig. A6.2 — Electronic admittance Ye of a solid electron beam of radius b and circuit 



admittance Yc of a helix of radius a plotted vs. real values of the propagation constant 



dY,, dYc 

 y in the vicinity of where . ' = , where complex solutions for y are expected, for two 

 ay ay 



typical sets of operating conditions. Plotted on the same graph is the electron admit- 

 tance Yen for two equivalent hollow electron beams: the dashed curve (Fletcher) is matched 

 to F, at n = 0, while the dot-dashed curve (Pierce, Appendix IV) is matched at « = 1 

 (of! the graph). 



