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BELL SYSTEM TECHNICAL JOURNAL 



with protons and possibly neutrons figuring among the revolving 

 particles. He will be looking too far into the future, and will be dis- 

 appointed with the present. The present nucleus-model consists of 

 little more than a single curve — a curve which, moreover, relates 

 only to the fringe of the nucleus and to the region surrounding it, and 

 for want of knowledge is not extended into the central region or 

 nucleus proper where the constituent particles must be. The theory 

 which it serves is a theory not of the nucleus as a stable system of 

 corpuscles, but of the escape of some from among these corpuscles 

 and the entry of new ones — a theory professing to deal only with the 

 entry and the escape, not at all with the events succeeding the one or 

 preceding the other. 



The curve purports to portray the electrostatic potential, as function 

 of r the distance measured from the centre of the nucleus, from r = co 

 inward to a minimum distance which is indeed very small even in the 

 atomic scale — 10"^^ cm. or less — but still definitely not zero, since the 

 components of the nucleus must be presumed to be normally at 

 distances yet smaller. When it is plotted as in Fig. 12, its ordinate 



Fig. 12 — Nuclear potential-curve postulated for explaining transmutation (without 

 allowance for resonance) and radioactivity. 



at any r is a measure of the amount of kinetic energy which a posi- 

 tively-charged particle approaching the nucleus must sacrifice — i.e. 

 which must be converted into potential energy — in order to come 

 from infinity to r. Traced from infinity inward, the curve must 

 follow at first the function const, jr, corresponding to the inverse- 

 square law of force; for it is known, both from experiments on alpha- 

 particle scattering (which supplied the foundation for the contemporary 

 atom-model) and from the successes of the theory of atomic spectra, 

 that beyond a certain distance a nucleus is surrounded by an inverse- 



