PART I 



THE GROWING NOISE PHENOMENON 



819 



35 



30 

 25 

 20 



15 

 10 



2 4 6 8 10 12 14 16 18 



Z IN INCHES ALONG DRIFT TUBE (0 IS 0.95" FROM ANODE) 



8 = 256 GAUSS, Bc = 14 GAUSS, V=2200 VOLTS, 1 = 31.2 MA 



Fig. 8 (d), (e) — Noise power at the difference-frequency, 3,225 mc, is recorded, 

 with and without the signals (b) and (c) present. The difference in ordinates of 

 the two curves increases with distance from the gun, as the impressed signals 

 grow and the beam becomes more non-linear. 



(3) sufficient pha.se shift between inner and outer ripple.s in the beam 

 tor one to de-aniphfy as much as the other amphfies; and 



(4) interference among the intermodulation products excited at differ- 

 ent positions along the beam.* 



1 The last effect is illustrated in Fig. 9, in exaggerated form. The beam 



* Suggested I)}- C. C. Cutler of Bell Telephone Laboratories. 



