ABSTRACTS OF TKCHNICAL AUTICLES 261 



A positive charge on the surfuce of a p-ty\)e geinumiuin crystal induces a 

 net negative space charge witliin tlie crystal adjacent to the surface. This 

 space charge is coni]iosed of ionized accei)tor atoms and also of electrons 

 under certain conditions. When electrons occur they provide a layer of 

 ?i-tyi)e conductivity immediately under the p-type germanium suiface. 

 Such a layer has been found on the p-type region of some n-p-?i-transistors. 

 In the 7i-p-n structure the layer of electrons appears as an extra conducting 

 path — "a channel" — aci'oss the p-type mateiial between the two n-tyi)e 

 ends. The conductance of a channel and the capacity between the channel 

 and the /)-ty])e material have been measured and com))aied with the the- 

 oretical predictions liased on a sin^ple model, 



Cornell, L. P., see E. P. Smitpl 



Crane, G. R.^ F. Hauser^ and H. A. Manley^ 



Westrex Film Editor, J.S.M.P.T.E., 61, Part 1, pp. 316-323, Sept., 

 1953. 



This paper describes a film-editing machine which emploj's continuous pio- 

 jection resulting in ciuiet operation. It accommodates standaid-picture and 

 photographic or magnetic sound film as well as composite sound-picture 

 film. Differential synchronizing of sound and picture while running, auto- 

 matic fast stop and simplified threading features in the film gates with 

 finger-ti]) release materially increase operating efficiency. 



Crissman, h.^ 



See Both Sides of the Game, Tele-Tech., 12, p. 84, Sept., 1953. 



DaCEY, G. C.l AND I. M. PvOSSl 



Unipolar "Field-Effect" Transistor, I.R.E., Proc, 41, pp. 970- 

 979, Aug., 1953. 



Unipolar "field-effect" transistors of a type suggested by W. Shocklej- have 

 been constructed and tested. The idealized theory of Shockle\' has l)een ex- 

 tended to cover the actual geometries involved, and design nomographs are 

 presented. It is found that these structures can be designed in such a way 

 as to jdeld a negative resistance at the input terminals. The characteristics 

 of several units are presente<:l and analyzed. It is shown that these character- 

 istics are in substantial agreement with the extended theory. Finally a specu- 

 lative evaluation of the possible future applications of field effect transistors 

 is made. 



1 Bell Telejihone Laljorat cries. 

 3 Western Electric Company. 

 * Westrex Corporation. 



