510 THE BELL SYSTEM TECHNICAL JOURNAL, MARCH 1954 



fill mode is excited l^etween 1,600 and 4,000 volts, the tube tuning con- 

 tinuously between 6.0 and 7.5 mm, thus covering a freciuency band of 10,000 

 mc. Power output of about 10 mw has been measured at 6.4 mm. The 

 tube has also been studied as an am])lifier and more than 20-db stable 

 backward gain has been obtained. A simple theorj- of backward gain and of 

 oscillation starting conditions is given. 



Lander, J. J.^ 



Auger Peaks in the Energy Spectra of Secondary Electrons from 

 Various Materials, Phys. Kev., 91, pp. 1382-1387, Sept. 15, 1953. 



The energy spectra of secondary electrons from carbon, beryllium, alumi- 

 num, nickel, copper, barium, platinum, and the oxides of ber3dlium, alumi- 

 num, nickel, copper, and barium have been measured with eciuipment of 

 high stabilit}^ and sensitivity. Charactei'istic peaks due to Auger electrons 

 emitted as a result of absori)tion of a valence electron l\v an excited x-ray 

 level were observed for all these materials. The peaks exhibit structure 

 which is of some theoretical interest. The structure can be related to the 

 distribution in energy of electrons in the valence band, and it complements 

 that observed in soft x-ray emission work. Since the emission of the Auger 

 electron is not subject to the selection rules governing the emission of x-ra- 

 diation, additional information can be obtained from the Auger election 

 energy disti'ibution. Excitation of Auger peaks bj' a beam of low velocity 

 electrons provides an intei'esting technique for surface analysis. "Plasma" 

 peaks of the type repoited by Ruthemann, and inter])ieted b\' Pines and 

 Bohm, were also observed. 



LovELL, G. H., see L. H. Morris. 



Montgomery, H. C.^ and M. A. Clark. ^ 



Shot Noise in Junction Transistors, Letter to the Editor, J. Appl. 

 Phys., 24, pp. 1337-1338, Oct., 1953. 



Morris, L. H.,i G. H. Lovell^ and F. R. Dickinson.^ 



L3 Coaxial System — Amplifiers, A.I.E.E. Trans., Commun. & Elec- 

 tronics, 9, pp. 505-517, Nov., 1953 (Monograph 2090). 



The line amplifiers for the L3 coaxial system are designed to compensate for 

 the loss of the 4 miles of cable which separate the I'epeaters; the flat am- 

 plifiers are used to compensate for eciuilizer loss and as transmitting am- 

 plifiers. The two types are basically similar, consisting of two feedback 

 amplifiers in tandem, separated by an interamplifier network; in the line 

 amplifier, this network is variable, and is automaticallj^ adjusted to com- 



Bell Telephone Laboratories, Inc. 



