A simple excursion model of a nuclear explosive device

An analytical model based on basic physics and on a third-order ordinary differential equation is presented to describe the sequence of events during an excursion of a nuclear explosive device. The model is subdivided into two parts: (a) the time span up to the boiling point without any relevant feedback mechanism, and (b) the time span beyond the boiling point where a strong feedback mechanism exists due to the expanding core volume.The model yields reasonable results which were cross-checked repeatedly.