Artificial Radioactivity giving Continuous γ-Radiation

In many cases of nuclear transformations, unstable nuclei are obtained which break down emitting positive electrons (+-decay). Because this nucleus is surrounded by orbital negative electrons, the positive electron produced can recombine with one of the negatives giving rise to a-ray quantum1. The force responsible for recombination is proportional to e (electronic charge). The probability of such a recombination thus involves the factor e2. Therefore the ratio of the probability of observing a-ray quantum to that of finding a positive electron must be of the order of magnitude e2/hc102 (e2/hc being the only dimensionless number which can be formed from e, the Planck constant h and the velocity of light c).