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 A01: Nuclear Structure of Exotic Nuclei I |
Hide Abstracts |
Chair: Mark Spieker, FSU Room: East Ballroom |
Thursday, November 18, 2021 9:30AM - 10:00AM |
A01.00001: Tipping the nuclear scale: beta-decay spectroscopy of (very) neutron rich nuclei Invited Speaker: Miguel Madurga The continuing development of production and separation techniques allowing for the study of nuclei far away from the line of stability has spurred the low energy nuclear field for the past 3 decades. Large proton-neutron imbalances drive emerging exotic phenomena such as shape coexistence or halo distributions of nuclear matter, which in turn have helped refine our understanding of the nuclear interaction in the nuclear medium. In this talk I will discuss our experimental efforts using beta-delayed gamma and neutron spectroscopy to characterize the nuclear structure of neutron rich nuclei around doubly magic 32Mg, 78Ni, and 132Sn. In particular I will concentrate in the role nucleon excitations across shell closures play in all three regions, driving both increasingly smaller decay-half lives and larger neutron branching ratios. [Preview Abstract] |
Thursday, November 18, 2021 10:00AM - 10:15AM |
A01.00002: Near-threshold proton resonances in11B Eilens Lopez Saavedra The study of near-threshold proton resonances in 11B has been the object of several recent theoretical and experimental studies due to its unique structural and decay properties. An experiment to search for charge particles decaying from low-lying, low spin resonance states in $^{11}$B was performed at the John D. Fox Superconducting Linear Accelerator Laboratory at Florida State University, using a radioactive 10Be beam via the 10B(d,n) reaction. The 11B recoils were measured in coincidence with an array of silicon detectors where protons and alpha particles decaying from unbound states in 11B were identified. Details on the experiment and preliminary results will be presented in this work. [Preview Abstract] |
Thursday, November 18, 2021 10:15AM - 10:30AM |
A01.00003: Mass measurements of neutron-rich Cr isotopes to investigate the N$=$40 island of inversion Roshani Silwal, Andrew Jacobs, Ania Kwiatkowski Atomic mass measurements of short-live radioactive isotopes are useful to determine the nuclear structure and deviations from the existing nuclear models, and to explore the nuclear astrophysics reaction paths that are responsible for creating visible matter. Here, we present the mass measurement of neutron-rich chromium isotopes using the extremely sensitive electrostatic Multiple-Reflection Time-Of-Flight Mass Spectrometer (MR-TOF-MS) at TRIUMF's Ion Trap for Atomic and Nuclear Science (TITAN) facility. Cr lies midway in the transition region between the Z $=$ 20 and 28 proton shell closures. This region is particularly interesting due to the onset and evolution of nuclear deformation as nuclei become more neutron rich. Combined with the state-of-the-art ab-initio models, we investigate the N$=$40 island of inversion using our precise measurements of $^{59-65}$Cr. The new measurement allows for the extension to the mass surface beyond N$=$40 and provides a challenging testing ground for emerging ab-initio nuclear structure models. [Preview Abstract] |
Thursday, November 18, 2021 10:30AM - 10:45AM |
A01.00004: Development of a Prototype Electron Detector for Use in UCNA$+$ Experiment Richard McDonald, Robert Pattie The UCNA Experiment at the Los Alamos Neutron Science Center (LANSCE) uses an electron spectrometer to observe angular correlations between the spin polarization of ultracold neutrons and the momenta of $\beta $ particles emitted from the beta-decay of free neutrons. The asymmetry of these beta-emissions yields a value of $\lambda $, defined as the ratio between the axial vector and vector coupling constants ($\lambda =g_{A}$/$g_{V})$. In combination with the neutron lifetime, these parameters have the capability of pointing out physics Beyond the Standard Model by testing the unitarity of the Cabibbo-Kobayashi-Maskawa Matrix. The UCNA Collaboration is exploring ways to increase the sensitivity of the experiment, and one improvement that can be made is updating the organic scintillator detector. Rather than using PMTs, this study plans to evaluate the possibility of using edge coupled solid state silicon photomultiplier detectors (SiPMs), which can record energy, position, and time data. The new configuration of the detector may also result in lower systematic uncertainties; namely the \textasciitilde 2 meter path the produced light must travel to reach the PMTs and the SiPMs' quantum efficiency being a factor of 2 greater than the PMTs'. Over the course of the past summer, Dr. Pattie and I have been building a prototype detector and automated source positioner for evaluating the SiPMs as the only detectors present, the goal being to compare the position and energy resolution with that of the current detector used by UCNA. [Preview Abstract] |
Thursday, November 18, 2021 10:45AM - 11:00AM |
A01.00005: Electronics development for the full implementation of the Neutron dEtector with Xn Tracking (NEXT) array Noritaka Kitamura, Robert Grzywacz, Shree Neupane, Joseph Heideman, Jason Chan Beta-delayed neutron spectroscopy is essential to obtain nuclear structure information of very neutron-rich unstable nuclei. The Neutron dEtector with Xn Tracking (NEXT) array was designed to enable high-resolution neutron energy measurements via the time-of-flight method while maintaining high neutron detection efficiency [1]. Following the initial design phases of NEXT prototypes, the construction of 40 NEXT modules is ongoing. For the full implementation of the NEXT array, dedicated high-density triggering and readout schemes are required, and thus the readout electronics have been continuously improved. We will present NEXT construction status with a special focus on its electronics developments. [1] J. Heideman et al., Nucl. Instrum. Methods Phys. Res., Sect. A 946, 162528 (2019). [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