. The Bell System technical journal . ent nucleus-model consists oflittle more than a single curve—a curve which, moreover, relatesonly to the fringe of the nucleus and to the region surrounding it, andfor want of knowledge is not extended into the central region ornucleus proper where the constituent particles must be. The theorywhich it serves is a theory not of the nucleus as a stable system ofcorpuscles, but of the escape of some from among these corpusclesand the entry of new ones—a theory professing to deal only with theentry and the escape, not at all with the events succeeding the one
. The Bell System technical journal . ent nucleus-model consists oflittle more than a single curve—a curve which, moreover, relatesonly to the fringe of the nucleus and to the region surrounding it, andfor want of knowledge is not extended into the central region ornucleus proper where the constituent particles must be. The theorywhich it serves is a theory not of the nucleus as a stable system ofcorpuscles, but of the escape of some from among these corpusclesand the entry of new ones—a theory professing to deal only with theentry and the escape, not at all with the events succeeding the one orpreceding the other. The curve purports to portray the electrostatic potential, as functionof r the distance measured from the centre of the nucleus, from r = coinward to a minimum distance which is indeed very small even in theatomic scale—10^^ cm. or less—but still definitely not zero, since thecomponents of the nucleus must be presumed to be normally atdistances yet smaller. When it is plotted as in Fig. 12, its ordinate. Fig. 12—Nuclear potential-curve postulated for explaining transmutation (withoutallowance 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— must be converted into potential energy—in order to comefrom infinity to r. Traced from infinity inward, the curve mustfollow 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 contemporaryatom-model) and from the successes of the theory of atomic spectra,that beyond a certain distance a nucleus is surrounded by an inverse- CONTEMPORARY ADVANCES IN PHYSICS, XXVIII 595 square force-field. This is the obstacle, or at any rate, a part of theobstacle, which an oncoming proton or deuton or alpha-particle mustovercome in order to reach the nucleus and
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
