The theory of the effect of resonance levels on artificial disintegration

According to the theory first proposed by Gamow, and by Gurney and Condon, the emission of a-particles by radio active nuclei is to be explained by the assumption that there exists in the nucleus a “virtual” level of positive energy, which is occupied by an a-particle. According to the wave mechanics, such levels are necessarily unstable, and there exists a definite probability that the α-particle will escape in a given interval of time. The theory has been discussed by a great many authors; we shall need to refer in particular to the calculations of Fowler and Wilson, who have given the exact wave function that describes the emission from a simplified one-dimensional nucleus.