Improving systematic predictions of beta-delayed neutron emission probabilities

The probability for neutron emission following $\beta$ decay, P$_n$, is a crucial property for a wide range of physics and applications including nuclear structure, astrophysics, the control of nuclear reactors, and the post-processing and handling of nuclear fuel. Despite much experimental effort, knowledge of P$_n$ values is lacking in very neutron-rich nuclei, requiring predictions from either systematics or theoretical models. Traditionally, systematic predictions [1] were made by investigating the P$_n$ value as a function of the $Q$ value of the decay and the neutron separation energy. Here, we will present a new form of systematic studies utilizing the well-known relationship between the P$_n$ value and the half-life of the decay. It will be shown that such systematics provide more robust predictions of P$_n$ values compared with earlier prescriptions, are applicable to all known $\beta$-delayed neutron emitters across the nuclear chart, and are a general feature of not only the data, but also the theoretical models.\\[4pt] [1] B. Pfeiffer {\it et al.,} Prog. Nucl. Energy {\bf 41}, 39 (2002).