Speaker
Description
The astrophysical rapid neutron capture process (r-process) is thought to be responsible for the production of roughly half of the heavy elements found in nature. At present the site and many other details of this process remain uncertain, making the detailed understanding of the r-process one of the most active areas of research in nuclear astrophysics. Testing the models describing the r-process requires experimental nuclear data such as masses, beta-decay properties, and neutron-capture rates among neutron-rich nuclides, far from the region of stability. Such data are sparse and because it is difficult for experiments to access the nuclides of interest. Radioactive ion beam (RIB) facilities have been a valuable resource in addressing this problem. As existing RIB facilities improve and next-generation facilities come online, the opportunities to obtain such data are quickly growing. They should provide a wealth of new nuclear data, and make it possible to evaluate and improve the results of existing r-process calculations, and possibly inspire new approaches.
One such facility is CARIBU, located at Argonne National Laboratory, where intense beams of neutron-rich isotopes are produced from the spontaneous fission of 252Cf. The Canadian Penning Trap (CPT) mass spectrometer uses the ion-beams produced by CARIBU to determine the masses of nuclides, near the r-process path. Recent improvements to our apparatus include the addition of a high-resolution multiple reflection Time-of-Flight (MR-TOF) mass spectrometer, and the implementation of a contemporary Phase-Imaging Ion-Cyclotron-Resonance (PI-ICR) mass measurement technique. These enhancements allow use to press further from the region of stability and ever closer to nuclides that lie on the proposed path of the r-process.
An overview of the current configuration of our apparatus and some highlights from our recent results will be presented.
