TUNL Neutron Beam Experiments

A group of 12 researchers from the MoNA Collaboration, including 5 undergraduate and 2 graduate students, recently visited the Triangle Universities Nuclear Laboratory (TUNL) at Duke University in Durham, NC. The team used an 11-MeV neutron beam from TUNL's tandem accelerator to test prototype neutron detectors. The team had excellent local support by Sean Finch, Forrest Friesen, and Michelle Riemann.

The detectors were built from test kits at Augustana College, Davidson College, Hope College, James Madison University, Michigan State University, and Virginia State University, and consist of plastic scintillators and various configurations of SiPM arrays. Different types of optical coupling and reflective wrapping were used. The collected data will be used in benchmarking current neutron detector simulation tools and play an important role in developing the next generation neutron detector, which was recently approved for funding by the National Science Foundation [https://www.nsf.gov/awardsearch/showAward?AWD_ID=2320400].

Professor Frank positions a SiPM based detector module for testing.

Closeup of a test module

Students, faculty, and staff involved in the TUNL run

Los Alamos experiments

Members of the MoNA collaboration went to the Los Alamos Neutron Science Center (LANSCE) July 24-28, 2023 to help prepare for an upcoming experiment to better understand neutron scattering and detection. The group consisted of participants from Davidson College, Indiana Wesleyan University, Michigan State University, and Virginia State University.

The group stands in front of the replica Main Gate from Manhattan Project era

PAC 2

The second Program Advisory Committee (PAC2) of the Facility for Rare Isotope Beams met on March 1-3, 2023. A total of 11,859 facility-use hours were submitted to PAC2 and 4,127 hours (35%) could be approved due to the limited beam time available. The MoNA Collaboration submitted five proposals in partnership with other researchers outside of the collaboration, two of which were approved by the PAC.

The two approved proposals are :

23033 - Investigating the halo structure of 37Mg - A. Revel

23068 - Study of possible p-wave halo in 34Na ground state - B. Monteagudo-Godoy

Those two experiments aim to improve our understanding of phenomena arising when moving away from the valley of beta-stability and in particular on the formation of neutron halos, often observed uniquely in nuclei close to the neutron dripline. Both experiments will shed light on the interplay between deformation, shell evolution, halo formation and coupling to the continuum. The two nuclei of interest, 37Mg and 34Na, will be studied using kinematically complete Coulomb breakup measurement in order to map the dB(E1)/dErel function and extract key information such as the geometrical information of the halo, the neutron separation energy, the ground state and its configuration mixing. The invariant-mass method will be used to reconstruct the relative energy following the Coulomb breakup reaction. The neutron will be detected by the MoNA-LISA array and the recoil fragment will be deflected by the sweeper magnet before to be measured by a set of detectors. In addition, eventual decays towards bound states will be observed using the CAESAR CsI array placed around the target.