The spontaneous fission of heavy nuclei into very unequal fragments

The recently observed radioactive decay of Ra and other heavy nuclei by the emission of C and Ne may be interpreted in terms of a simple barrier penetration process similar to both α-decay and spontaneous fission. In the simplest version of such a theory, when parent and daughter nuclei are all assumed to be spherical, closed formulae for the logarithms of the decay lifetimes may be derived which, without the adjustment of any parameters, reproduce the data to within several percent. A discussion of possible refinements to the simplest treatment, associated in particular with nuclear deformations is given