DREB Conference 2024

The ${}^{32}$Si(t,p)${}^{34}$Si reaction was measured in inverse kinematics at a 6.3 MeV/u incident energy using the SOLARIS spectrometer at FRIB in order to study the structure of nuclei around the “island of inversion”. Outgoing protons were measured over an angular range of ~20-40 degrees (center-of-mass) and populated excited states of ${}^{34}$Si were identified at energies up to 7 MeV. Additionally, the ${}^{32}$Si(${}^3$He,d)${}^{33}$P reaction was simultaneously measured, where populated excited states in ${}^{33}$P were identified at energies up to 5 MeV. Due to the nature of the data taken, several machine learning methods were utilized for event identification, including multi-class classification predictive modeling and anomaly detection. Analysis is ongoing; measured proton angular distributions from the (t,p) reaction for most states will be used in comparison with distorted wave Born approximations (DWBA) calculations to make tentative spin assignments, and the deduced spectroscopic amplitudes will be compared with occupation numbers from shell-model calculations. In addition, a complementary experiment, the ${}^{34}$S(t,p$\gamma$)${}^{36}$S reaction to be carried out with the HELIOS spectrometer at the ATLAS facility at Argonne National Lab, will be discussed in terms of a more complete systematic study in the region.

This work was supported by the US Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. This material is based upon work supported by NSF’s National Superconducting Cyclotron Laboratory which is a major facility fully funded by the National Science Foundation under award PHY-1565546; the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract Number DE-AC02-06CH11357 (Argonne) and under Award Number DE-SC0014552 (UConn); the Spanish Ministerio de Economia y Competitividad through the Programmes "Ramon y Cajal" with the grant number RYC2019-028438-I; the U.K. Science and Technology Facilities Council (Grant No. ST/P004423/1); and the International Technology Center Pacific (ITC-PAC) under Contract No. FA520919PA138. SOLARIS is funded by the DOE Office of Science under the FRIB Cooperative Agreement DE-SC0000661.