21Ne and the Lighter Heavy Elements
Within the range 26<Z<47 there is an observed overabundance of elements when compared to model predictions of nucleosynthesis. One possible solution is an extension of the s-process to rapidly rotating metal poor stars. However, there is significant uncertainty in nucleosynthesis models of these stars, primarily in the ratio of 17O(α,γ)21Ne / 17O(α,n)20Ne. Due to low cross-sections, these reactions cannot be directly measured and must be modelled. These models depend upon the spin-parities of the energy levels of 21Ne within the Gamow window. Unfortunately, several of these energy levels have unknown spin-parities. In order to better predict the rates of reaction, an experiment has taken place at HELIOS (Argonne) with the reaction 20Ne(d,p)21Ne that aims to determine the spin-parities for the resonances within the Gamow window by comparing Distorted-Wave Born Approximation predictions of angular-distribution to experimental measurements. It will also attempt to determine the neutron widths of these states. The astrophysical motivation behind the experiment and details of the ongoing analysis will be presented.