Bulletin of the American Physical Society
88th Annual Meeting of the Southeastern Section of the APS
Volume 66, Number 16
Thursday–Saturday, November 18–20, 2021; University Center Club, Florida State University, Tallahassee, Florida
Session G04: Nuclear Structure of Exotic Nuclei II |
Hide Abstracts |
Chair: Vandana Tripathi, Florida State University Room: West Ballroom |
Thursday, November 18, 2021 4:30PM - 5:00PM |
G04.00001: Structure of exotic nuclei out to the limits of existence Invited Speaker: Anthony Kuchera Atomic nuclei that are unstable with very short lifetimes are often referred to as exotic nuclei. Several changes to structural trends across the nuclear landscape have been observed as nuclei go farther from the line of stability. Examples include loosely bound nucleons with large radii, neutron skins, rare decay modes, and the appearance and disappearance of traditional magic numbers. The understanding of these exciting phenomena rely on state-of-the-art theory calculations and experiments often with sophisticated instrumentation and analysis techniques. Nuclei at the limits of existence are found at the driplines, where the last bound isotopes of an element are found. Experiments capable of observing and measuring properties of nuclei at these extremes can test and constrain modern nuclear structure models. The Modular Neutron Array (MoNA) is a high-efficiency plastic scintillator array designed to detect neutrons from the decay of neutron-unbound systems. Decay energies are reconstructed using invariant mass spectroscopy to understand the level structure and decay modes of the most exotic nuclei. Recent work from the MoNA Collaboration will be presented. [Preview Abstract] |
Thursday, November 18, 2021 5:00PM - 5:15PM |
G04.00002: Differential cross-section measurements of $^{18}$O(g,n)$+^{18}$O(g,2n) reactions at 23.7 and 32.0 MeV Collin Malone Photoneutron reactions on $^{18}$O allow examination of the neutron-neutron (nn) interaction and may be used as a surrogate for planning a $^{3}$H photodisintegration experiment at TUNL. The relatively large $^{18}$O($\gamma $,2n) cross section allows measurements of differential cross-sections for nn coincidences at various opening angles between the neutrons without risks associated with handling a radioactive gas target. Cross sections for the sequential and simultaneous emission of the two neutrons in the $^{18}$O($\gamma $, nn) reaction are measured. The simultaneous neutron emission provides information about neutron-neutron correlations in the $^{18}$O nucleus. Ab-initio calculations are needed to disentangle the simultaneous contribution from the aggregate cross section. The measurements were performed at HI$\gamma $S using a 23.7 and 32.0 MeV circularly polarized photon beam. Neutrons were detected using 30 liquid scintillator detectors at reaction angles of 65, 90, and 180\textdegree . Neutron energies were determined using time-of-flight techniques. These are the first differential cross-section data for $^{18}$O($\gamma $,n) and $^{18}$O($\gamma $,2n). A description of experimental techniques and preliminary results will be presented. [Preview Abstract] |
Thursday, November 18, 2021 5:15PM - 5:30PM |
G04.00003: Recent results of spectrum unfolding of the CATRiNA detectors Ashton Morelock, Sergio Almaraz-Calderon, Jesus Perello, Ben Asher, Eilens Lopez Saavedra, Zach Meisel, Thomas Massey, Justin Warren, Joseph Derkin, Gula Hamad, Alexander Voinov, Doug Soltesz, Shiv Subedi, Kristyn Brandenburg, Nisha Singh, Yenuel Jones-Alberty The CATRiNA deuterated neutron detector array at FSU has been expanded to include 16 additional EJ315 detectors, making it a powerful and sensitive neutron detector array. Neutron energies can be extracted using their pulse-height spectrum through a method known as spectrum unfolding. Characterization of the array was performed at the Edwards Accelerator Laboratory at Ohio University via reactions $^{9}$Be(d,n) and $^{27}$Al(d,n). Extraction of spectroscopic information from the $^{12}$C(d,n) reaction was also performed. In this work, results of these experiments and upgrades to the spectrum unfolding algorithm will be presented. [Preview Abstract] |
Thursday, November 18, 2021 5:30PM - 5:45PM |
G04.00004: Reaction for High Spin Spectroscopy with the SE-SPS and the Fox Lab Superconducting Linear Accelerator Caleb Benetti, Sam Tabor, Catur Wibisono, Gordon McCann, Ingo Wiedenhoever, Lagy Baby, Mark Spieker The investigation of nuclear structure in the mass 16-60 region has provided rich experimental data to test microscopic theory. Previously our group has used the tools and techniques of multi-gamma spectroscopy to chart out the high-spin yrast states in this mass region. It has been shown$^{1}$ that ($\alpha $,d) reactions also have a preference for high spin states since the proton and neutron from the deuteron can both occupy the same state of maximal J. Surprisingly no results for $^{27}$Al($\alpha $,d)$^{29}$Si have been published above 5MeV of excitation in $^{29}$Si. I will present recent work using the FSU Fox Lab Superconducting Linear Accelerator (Linac) as an energy booster with the Super FN Tandem accelerating an alpha beam on an Aluminum target. We have been able to achieve equivalent energy resolution using this accelerating scheme as one using the FN Tandem alone. This is the first time results from using the Linac and the Super Engie Split Pole Spectrograph (SESPS) together will be presented. $^{1}$B. G. Harvey and J. Cerny, Phys. Rev. \underline {120}, 2162 (1960). $^{2}$R.S. Lubna \textit{et al.} Phys. Rev. \underline {2}, 043342 (2020). [Preview Abstract] |
Thursday, November 18, 2021 5:45PM - 6:00PM |
G04.00005: The nuclear structure of $^{32}$P Catur Wibisono, Samuel Tabor, Vandana Tripathi, Elizabeth Rubino, Caleb Benetti, Alexander Volya The $^{32}$P nucleus was populated through two separate experiments at the FSU Fox Laboratory using $^{26}$Mg($^{11}$B, $\alpha n$) and $^{18}$O($^{16}$O,$p n$) reactions both at E$_{lab}$ = 30 MeV. Subsequent $\gamma$ decays were observed with 3 or 4 Clover spectrometers. $\gamma$-$\gamma$ coincidences were sorted into symmetric matrices and analyzed by projections. From the preliminary analysis using both data sets, several gamma ray transitions from the previous work as proposed by Chakrabarti \textit{et. al}\footnote{R. Chakrabarti \textit{et al.}, PRC \textbf{84}, 054325 (2011).} can be confirmed, however some of gamma ray transitions proposed to populate the yrast J$^{\pi}$=5$^{-}$ state cannot be confirmed, as will be discussed. Furthermore, the observed states were then compared with the FSU \textit{psdpf} shell model calculations\footnote{R. S. Lubna \textit{et al.}, PRR \textbf{2}, 043342 (2020).}. The two highest level states from the previous work which were also observed in the present work agree relatively well with the FSU 2ph configurations suggesting that cross-shell excitation might have a role not only in describing the negative parity states for the nuclei in the \textit{sd} shell, but also in describing the high spin positive parity states. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700