ABSTRACTS OF TECIIXICAL AUTH'LES 511 



pensato for variations in cable teniixTatuio, and tor small deviations I'roni 

 the nominal 4-niile spacing. 



PiKRCK, J. R.' 



Spatially Alternating Magnetic Fields for Focusing Low-Voltage 

 Electron Beams, Letter to the lulitor, J. Appl. Phys., 24, p. 1247, 

 Sept., 1953. 



PiEKCK, J. R.,' and L. R. Walker.i 



"Brillouin Flow" with Thermal Velocities, J. Appl. Phys., 24, pp. 

 1328-1330, Oct., 1953. 



A tj'pe of electron flow in a constant magnetic field is desciihed. The beam 

 of electrons is supposed to be everywhere in thermal equilibrium and the 

 usual Brillouin flow is found when the equilibrium temperature tends to 

 zero. Some considerations are put forward bearing on the choice of a suit- 

 able beam temperature in specific problems. 



Potter, J. L., see E. P. Felch 



Read, W. T., Jr.i 



Dislocations and Plastic Deformation, Physics Today, 6, pp. 10-14, 



Nov., 1953. 



Small and exceedingl}' rare defects in the structure of solids are the "weak 

 links" that determine the strength of materials. The article re\'iews some 

 fundamental concepts concerning i^lastic deformation in certain ductile 

 metals. 



RiORDAN, J., see L. Carlitz. 



RoMiG, H. G., see R. I. Wilkinson. 



Schnettler, F. J., see H. J. Williams. 



Sherwood, R. C, see H. J. Williams. 



Shockley, W.i 



Some Predicted Effects of Temperature Gradients on Diffusion in 

 Crystals, Letter to the Editor, Phys. Rev., 91, pp. 1563-1564, Sept. 

 15, 1953. 



' Bell Telephone Laboratories, Inc. 



