Facility for Rare Isotope Beams

In the past two decades, significant progress has been made with the discovery of elements Z=114-118 through reactions between 48Ca beams and actinide targets, achieving production rates of atoms-per-day or more. Unfortunately, the pursuit of elements beyond Oganesson (Z=118) faces substantial challenges, with no new elements have been discovered in the last 15 years. The synthesis of elements with Z=119 or 120 using 48Ca would necessitate targets of Es (Z=99) or Fm (Z=100), but these elements cannot be produced in sufficient quantities. This limitation necessitates exploring new reaction pathways.

 

Numerous theoretical studies have aimed at predicting production rates for new elements using actinide targets and heavier ion beams. While these models reliably reproduce excitation functions for SHE production with 48Ca beams, predictions diverge significantly for reactions involving heavier beams. For instance, the predicted cross section for reactions to produce Z=120 vary by more than three orders of magnitude and tens of MeV. These discrepancies hinder experimental efforts, as the low expected cross sections suggest the detection of only one event every few weeks or months under ideal conditions.

 

Berkeley Lab has been proactively addressing these challenges to push beyond E118. By testing theoretical predictions, we have begun the 50Ti+244Pu experiment to understand the impact of using 50Ti instead of 48Ca beams on cross sections. This presentation will highlight significant upgrades to our experimental facilities, including ion sources, target setups, detectors, and electronics, aimed at enhancing our capability to produce and detect elements beyond E118. We will also present the initial results from the 50Ti+244Pu experiment, showcasing our progress in this ambitious endeavor.

Classical novae are thermonuclear explosions that take place in the H-rich envelopes of accreting white dwarfs in stellar binary systems. The material piles up under degenerate conditions, driving a thermonuclear runaway. The energy released by the suite of nuclear processes operating at the envelope heats the material up to peak temperatures of (100 - 400) MK. During these events, about 10-7 - 10-4 solar masses, enriched in CNO, and sometimes, other intermediate-mass elements (e.g., Ne, Na, Mg, Al) are ejected into the interstellar medium. Infrared and ultraviolet observations of novae have confirmed grain formation in their expanding shells. This has raised the issue of the potential contribution of novae to the current inventory of presolar grains. I will review several studies that have led to the identification of a handful of presolar grains with isotopic signatures consistent with a nova origin. Mixing at the core-envelope interface still remains as an important unknown in the modeling of classical novae. I will review as well recent results from multidimensional simulations of mixing by hydrodynamic (Kelvin-Helmholtz) instabilities and shear. Strategies to export mixing prescriptions obtained from such multidimensional simulations for follow-up studies with 1D codes will also be discussed. Finally, I will also present recent recurrent nova models, aimed at characterizing T CrB, a system that should undergo an explosion imminently. In most recurrent novae, the mass of the accreting white dwarf is expected to be very close to the Chandrasekhar value, as imposed by their short recurrence periods. Simulations suggest that such white dwarfs grow in mass, making recurrent novae likely candidates for thermonuclear supernovae.

What do atomic nuclei look like? There are several known images of nuclei: liquid droplets, independent nucleons "moving" in a mean potential, and clusters of nucleons floating in the nucleus. One of the methods to capture the different images of nuclei is the knockout reaction. In this reaction, the components of the nucleus are knocked out by incident particles at intermediate energies. If the rest of the nucleus is not disturbed except for the knocked-out particle, it can be determined to what extent the knocked-out particle was present in the nucleus and how it moved. By knocking out nucleons or clusters, the image of the nucleus captured by the independent particle or cluster image emerges. In this talk I will give an overview of our recent activities on nucleon and cluster knockout reactions from stable and unstable nuclei. From a theoretical point of view, the focus will be on the development of a new reaction model, CDCCIA, for the knockout of fragile particles.

TBD

Gravitational waves are tiny ripples in the fabric of spacetime that travel to us from some of the most extreme events in our Universe, distant mergers of black holes and neutron stars. Observations of these events chart the history of stars through the collapsed remnants that are left behind at the end of their lives. Interpreting the patterns of their waves tells us about how these compact remnants orbit and spin, and can tell us how matter behaves at densities beyond that of an atomic nucleus. Mergers involving neutron stars are engines of transient astronomy, launching gamma-ray bursts and spreading newly created heavy elements into the universe. In this talk, I will tell some of the story of this new field of gravitational wave astronomy and show how our first detections are laying the groundwork for future observatories that can see across our entire Universe. Jocelyn Read is a Professor of Physics at California State University Fullerton in the Nicholas and Lee Begovich Center for Gravitational Wave Physics and Astronomy, and currently a Visiting Fellow at the Perimeter Institute. Her research connects the nuclear astrophysics of neutron stars with gravitational wave observations. She earned her Ph.D. in 2008 from the University of Wisconsin Milwaukee, where she developed a widely used model for dense matter inside neutron stars and produced first estimates of how gravitational waves from neutron star mergers would inform these properties. Her work has included proposed mechanisms for precursor flares in gamma-ray bursts, new methods for gravitational-wave cosmology, uncertainty quantification for neutron-star merger source modeling, and measurements of dense matter properties with LIGO and Virgo gravitational-wave observations. She is actively contributing to the development of the next-generation gravitational-wave observatory Cosmic Explorer. Read co-chaired the LIGO/Virgo Binary Neutron Star Sources Working Group from 2014 to 2016 and was part of the team awarded the 2016 Special Breakthrough Prize in Fundamental Physics for the discovery of gravitational waves. She co-led the Extreme Matter team of the LIGO-Virgo-Kagra Collaboration from 2016 to 2022, through the first discovery and analysis of gravitational waves from a neutron-star merger. She has held visiting positions at the California Institute of Technology and the Carnegie Observatories in Pasadena. Read chairs the Advisory Board for the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) and served on the Scientific Advisory Committee for the Australian Research Council Centre of Excellence for Gravitational Wave Discovery (OzGrav). She was elected a Fellow of the American Physical Society (APS) in 2019.

Nuclear reactions among charged particles in stars take place at energies generally well below the Coulomb barrier, so the Coulomb barrier penetration factor exponentially suppresses the cross sections down to values as small as few nanobarns or picobarns. Therefore, approaching astrophysical energies opens new challenges and calls for new approaches. I will introduce the mission of nuclear astrophysics and discuss how experiments are usually conducted. Then, I will focus on the use of indirect methods as complementary approaches to direct measurements, discussing in detail the asymptotic normalization coefficient (ANC) and the Trojan Horse Method (THM). These methods are used to deduce the astrophysical factors of reactions with photons and charged particles in the exit channel, respectively, with no need of extrapolation. I will present recent results of the application of the two methods as examples. First, I will discuss the 6Li(3He,d)7Be measurement used to deduced the ANC’s of the 3He+4He->7Be and p+6Li->7Be channels and the corresponding radiative capture astrophysical factors. Then, I will illustrate the THM measurement of the 27Al(p,a)24Mg astrophysical factor through the 2H(27Al,a24Mg)n reaction. The reaction rate of the 27Al(p,g)28Si reaction was also deduced thanks to the determination of the proton partial widths. Both the ANC and the THM applications made it possible to assess the occurrence or exclude the presence of resonances that could be responsible significant changes of the reaction rates at temperatures of astrophysical interest.

The Nuclear Science Summer School (NS3) is a summer school that introduces undergraduate student participants to the fields of nuclear science and nuclear astrophysics. NS3 is hosted by FRIB on the campus of Michigan State University (MSU). The school will offer lectures and activities covering selected nuclear science and astrophysics topics.

PAN introduces participants to the fundamentals of the extremely small domain of atomic nuclei and its connection to the extremely large domain of astrophysics and cosmology.

The PAN @ Michigan State Experience

• Learn about research in one of the top rare-isotope laboratories in the world.
• Get introduced to the fascinating fields of astrophysics, precision measurement, and nuclear science.
• Perform your own nuclear physics experiments.
• Meet researchers who are exploring a wide array of questions.
• Discover the surprising array of career opportunities in science.
• Experience the atmosphere of college life.
• Participants in the 2024 program get free room and board on campus (if required).