Probing Particle Emission Near The Drip Lines

Dr. Andrew Rogers (host Reviol/Dickhoff), Univ. of Massachusetts Lowell
November 10, 2017 at 12:00 pm
241 Compton
Event Description 

Nuclei near the neutron and proton drip lines play a key role in our understanding of astrophysics, weak-interaction physics, and nuclear structure. Properties of very neutron-rich systems are important for constraining the rapid neutron-capture (r-) process that is predicted to generate most of the elements heavier than iron. Of particular interest are decays involving beta-delayed neutron emission which can significantly affect the r-process reaction network, altering nucleosynthesis models of supernovae and neutron-star mergers. On the other side of the valley of stability, proton-rich (neutron-deficient) nuclei at and beyond the proton drip line define the rapid proton-capture (rp-) process and constrain our understanding of type I x-ray bursts — bright periodic flashes of x-rays emitted by accreting neutron stars. Our Nuclear Physics group at UMass Lowell is pursuing fundamental science in nuclear astrophysics as well developing novel instrumentation. For instance, our 7Li-enriched Cs_2-7LiYCl_6 (C7LYC) dual neutron-gamma scintillators show promise for low-energy nuclear science and measurements of beta-delayed neutrons [1]. The ability to perform neutron-spectroscopy with CLYC without time-of-flight techniques allows for increased solid-angle coverage since the detectors can be place close to the target, thereby compensating for the low intrinsic detector efficiency. At the same time, we have recently performed an experiment at NSCL to investigate the 72Kr rp-process waiting point through an implant-decay measurement of beta-delayed protons from the 73Rb nuclear sandbar [2]. I will discuss advances and experiences with CLYC as well as provide preliminary results from our recent beta-decay experiment.

  1. D'Olympia et al., Nucl. Inst. Meth. A694, 140 (2012), and A763, 433 (2014).
  2. Suzuki et al., Phys. Rev. Lett. 119, 192503 (2017)