A thorough evaluation of the 39K(p,γ)40Ca reaction rate was performed to better understand the nucleosynthesis of potassium in globular clusters. We found that significant discrepencies in previous measurements lead to large reaction rate uncertainties, and provided recommendations for future study to resolve those issues.
In this article, I outlined convenient methods for extending our Monte Carlo reaction rate calculation tool for including correlations between input parameteras. The consequences of these improvements on calculations were investigated.
This review article highlighted the statistical advances that have been made in experimental nuclear astrophysics over the last 10 years. Our group was instrumental in implementing these techniques.
The 18Ne(α,p)21Na reaction is one of the key uncertain reactions for understanding classical novae. We extended our Monte Carlo methods to allow for ambiguities in the spin-parity assignments, thus improving our estimates for the uncertainties in the reaction rate.
A summary of the advances that have been made over the last few decades is presented, focusing on work performed at TUNL.
Advanced techniques for nuclear reaction network integration were investigated. We found that Gear's method, a backward-differential method, yielded significant improvements over traditional methods in computational expense for many astrophysical environments.
A groundbreaking result that suggests that the cross section in 18F(p,α)15O could be different than previously thought. This result could have significant implications for the detection of fluorine in classical novae.
Monte Carlo reaction rate calculations provide temperature dependent probability density distributions that follow log-normal distributions. In this paper, I give recommendations on how to use those distributions in nucleosynthesis calculations.
The rates of the 22Ne+α reactions are important for understanding the production of s-process elements (50% of the elements heavier than iron). My collaborators and I thoroughly investigated the current ambiguities in the reaction rates and summarised their effects on nucleosynthesis.
The origin of R Corona Borealis stars, which have very low atmospheric hydrogen abundances, has been a mystery for over 200 years. One theory for their origin the the merging of white dwarf stars. In this study, we discovered that lithium can be produced during such mergers, adding credence to this scenario.
We performed a broad survey of nucleosynthesis in white dwarf merger events using an advanced nuclear reaction network.
A Monte Carlo method was developed to propagate nuclear physics uncertainties to their associated reaction rates, the important quantities in stars.
Precision nuclear astrophysics experiments require standard normalisation quantities, particularly resonance strengths. We used an alternative method that didn't rely on an assumed target composition by measuring the effect that neon has in an aluminum target.
A novel photo-excitation method was used to measure the spin-parities of states in 26Mg. We found that one state, previously assumed to contribute to the 22Ne+α reactions has unnatural parity. It cannot, therefore, contribute to those reactions, a finding that had significant implications for s-process nucleosynthesis
The LENA facility focuses on measuring cross sections important in astrophysics. These typically have very small cross sections, so an advanced γ-ray spectroscopy system was developed to reduce background in the primary detectors.