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BELL SYSTEM TECHNICAL JOURNAL 



We see at once that the electron velocity for maximum gain shifts mark- 

 edly as QC is increased. Hence, the region around & = is not in this case 

 worthy of a separate investigation. 



Fig. 8.7 — The .t's and y's for the three waves with zero loss id = Oi hut with space 

 charge (QC = .25). 



Kig. 8.8 The .v's and v's with greater space charge {QC = .5). 



It is interesting to {)lot the maximum value of .Vi vs. the j)arameter QL\ 

 This has, in effect, been done in Fig. 8.10, which shows B, the gain in db 

 per wavelength per unit C, vs. QC. 



We can obtain a curve i)roportional to db per wavelength by plotting 

 BQC vs. QC. {Q is indei)endent of current.) This has been done in Fig. 

 8.11. I'or QC < 0.025, the gain in dh per wavelength varies lincarlv with 



