Reliability of Atomic Masses in the Chromium – Germanium Region

Abstract

FOR the past thirty years, beginning with F. W. Aston's observation of small deviations from his whole-number rule, the mass spectrograph has been used for determining atomic masses. One of the first significant results of this work was the experimental proof¹ by Bainbridge in 1933 of Einstein's mass–energy relationship. This led to the frequent use of atomic masses to check the correctness of experiments which measured the energy balance in nuclear transformations. In the intervening years the accuracy with which atomic masses can be determined by mass spectroscopy has greatly improved: however, the techniques for studying nuclear reactions have more than kept pace. As a result, when a discrepancy now exists between mass spectroscopic and transmutation values, the mass spectroscopist often finds himself playing the part of uncomfortable defendant, rather than that of patronizing judge. Such is our position in this communication.