Speaker
Description
Nuclear reaction rates in stars are determined from the folding of the Maxwell Boltzmann distribution with the reaction cross section. The latter quantity describes the likelihood of interaction of two particles at a particular energy. One of the main roles of nuclear physics in the field of nuclear astrophysics is to provide information about these cross sections.
There are many direct and indirect ways to determine these cross sections experimentally. One of the most influential types of direct measurements is the active-target technique. This technique involves using a gas-filled detector in which the detection medium is also the target. While powerful, they come with some drawbacks intrinsic to their design. First, the total beam intensity that can be delivered to these experiments is limited due to the ionization within the gas detector-target. Second, these measurements have an energy resolution which is much larger than the energy scales of the resonances which are typically found in these cross sections. This can result in the loss of critical information due to the limited energy resolution.
The typical approach has been to measure the cross section at higher energies and then to extrapolate that cross section using a statistical Hauser-Feshbach code, such as TALYS, at lower energies. These extrapolations are then used to determine the reaction rates in the astrophysical region of interest. There are uncertainties which come from this approach, but these are not well quantified. Understanding the relationship between the energy resolution and the inferred reaction rate is critical in design of successful future experimental apparatus.
We aim to provide a computational framework for assessing the uncertainties which arise from these thick-target active-target measurements, and to compute expected uncertainties due to energy resolution effects.
| Career stage | Early-career researcher (within 5 years of PhD) |
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