Alpha preformation probability
= Alpha preformation probability
{title2=$\lambda=\nu P_{\rm pre}T$}
The <alpha preformation probability> is a model-dependent nuclear-structure factor multiplying an interior assault <frequency> and barrier <transmission probability> in an alpha-decay rate estimate. It accounts for the availability of an alpha-like cluster at the matching surface. It is not fixed by the exterior Coulomb tunnelling exponent alone.