Speaker
Description
Almost half of the elements heavier than iron are produced through the r-process. While it is now recognized that the r-process occurs in neutron star mergers, evidence suggests additional sites must also contribute. One such possibility is core-collapse supernovae, which are predicted to be driven by the weak r-process, where heavy elements are synthesized via a series of ($\alpha$,n) reactions. A sensitivity study by Bliss et al. identified 45 ($\alpha$,n) reactions that significantly influence the abundances of elements produced in core-collapse supernovae [1]. Furthermore, ($\alpha$,n) reactions play a critical role in neutron production for the s-process in AGB and massive stars. Accurately measuring ($\alpha$,n) reaction rates is, therefore, key to understanding the origins of elements in the Universe.
To address this, the DEMAND array has been developed to study ($\alpha$,n) reactions directly in inverse kinematics with the DRAGON recoil separator at TRIUMF. The array consists of eight organic glass scintillator detectors used to detect the neutrons produced in these reactions. A proof-of-principle experiment was conducted to measure the 1434-keV resonance in the $^{22}$Ne($\alpha$,n)$^{25}$Ne reaction. This resonance was chosen as it has previously been measured in normal kinematics and is known to have a very strong resonance strength (1.067 eV) [2], making this an ideal test case. Preliminary results from this experiment demonstrate the detector's excellent pulse shape discrimination capabilities and confirm the feasibility of this novel approach.
[1] J. Bliss et al., Phys. Rev. C 101, 055807 (2020)
[2] M. Jaeger et al., Phys. Rev. Lett. 87, 20 (2001)
| Your current academic level | Postdoctoral fellow |
|---|---|
| Your Email | breed@triumf.ca |
| Affiliation | TRIUMF/Saint Mary's University |
| Supervisor | Chris Ruiz |
| Supervisor Email | ruiz@triumf.ca |
