152 The Electron Microscope 



** V. E. CossLETT, Introduction to Electron Optics, Oxford 



U.P., 1946. 

 ^ W. Glaser, Geometrical Electron Optics of the Axially 



Symmetrical Electromagnetic Eield, Z. Physik, 81, 647 



(1933). 

 ^ L. Opatowski, The Refractive Index of Electron Optics, 



Phys. Rev., 65, 54 (1944). 

 ^ L. Brillouin, Theory of the Magnetron, Phys. Rev., 60, 385 



(1941). 

 ^ O. ScHERZER, On Some Errors of Electron Lenses, Z. Physik, 



101, 593 (1936). 

 ^ D. B. Langmuir, Theoretical Limitation of Cathode Ray 

 Tubes, Proc. Inst. Radio Engrs., 25, 977 (1937). 



^^ E. ScHRODiNGER, Collected Papers on Wave Mechanics, 

 Blackie, London. 



^^ G. P. Thomson, Wave Mechanics of the Free Electron, Ox- 

 ford U.P. 

 G. P. Thomson and W. Cochrane, Theory and Practice of 

 Electron Diffraction, Macmillan, London, 1939. 



^2 R. P. Johnson and W. Schockley, An Electron Micro- 

 scope for Filaments : Emission and Absorption by Tungsten 

 Single Crystals, Phys. Rev., 49, 436 (1936). 

 R. P. Johnson, Simple Electron Microscopes, /. Applied 

 Phys., 9, 508 (1938). 



13 E. W. Muller, Z. Physik, 106, 541 (1937); 108, 668 

 (1938). 



1^ M. Benjamin and R. O. Jenkins, The Distribution of Auto- 

 electric Emission from Single Crystal Metal Points : Part I, 

 Tungsten, Molybdenum, Nickel in the Clean State, Proc. 

 Roy. Soc. (London), A, 176, 262 (1940) ; Part II, The 

 Absorption, Migration, and Evaporation of Thorium, 

 Barium, and Sodium on Tungsten and Molybdenum, Ibid., 

 180,225 (1942). 



1^ E. Bruche and H. Johannson, NaturwissenscJiaffen, 20, 49 

 (1932); 20, 353 (1932) ; Ann. Physik, 15, 145 (1932). 



1^ H. Busch and E. Bruche, Beitriige zur Elektronenoptik, 

 J. A. Barth, Leipzig, 1937; articles by R. Suhrmann, p. 61 

 and by H. Mahl, p. 73. 



1^ M. Knoll and E. Ruska, Das Elektronenmikroscop, 

 Z. Physik, 78, 318 (1932). 



