[Triumf-seminars] TRIUMF Colloquium today at 14:00

[TRIUMF Seminars]

Date/Time: Thu 2019-04-04 at 14:00

Location:  Auditorium          

Speaker:   Moshe Friedman (NSCL)

Title:     Beta-Delayed Charged Particle Measurements for Studies of Novae and X-ray Bursts

Abstract: Classical novae and type I X-ray bursts are energetic and common thermonuclear astrophysical explosions. However, our ability to understand these events is limited by the lack of comprehensive nuclear data on proton-rich nuclei. Specifically, constraining the 30P(p,gamma)31S and 15O(alpha,gamma)19Ne reaction rates has been found to be crucial to the understanding of nucleosynthesis and energy generation in these events. As direct measurements of these reactions are not technically feasible at the present time, indirect measurements of dominant resonance strengths by beta-delayed protons and alpha particles are used.
A gas-filled detector of beta-delayed charged particles has been designed and built to measure the 31Cl(beta+p)30P and the 20Mg(beta+p alpha)15O decays at NSCL. The detector is coupled with the Segmented Germanium Array (SeGA) to enable coincidence gamma-ray detection as an additional probe of the decay scheme and for normalization purposes. The first phase of the detector functions as a proton calorimeter, was successfully commissioned with 25Si(beta+p)24Mg, and used to measure several decays of interest including 31Cl. We will report on the performance of the detector and present preliminary results. We will also discuss the upgrade of the detector into a TPC for the measurements of the 20Mg(beta+p alpha) sequence.

Stimulants available 15 minutes before the talk.

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