Mass measurements of r-process nuclei with the TITAN MR-TOF-MS

Mr. Andrew Jacobs
University of British Columbia/TRIUMF

With the detection of the binary neutron-star merger GW170817, several key observations were made of the electromagnetic counterpart AT2017gfo. Primarily, the early blue emission of the kilonova implied the production of elements in the first r-process peak, while the later red emission indicated the production of lanthanides. Additionally, Sr has been the only element specifically identified in the ejecta. To better predict isotopic production from these mergers using nucleosynthesis network calculations, experimental nuclear inputs such as masses, half-lives, and decay channels are needed from neutron-rich nuclei in the r-process path. To this end, the Multiple-Reflection Time-of-Flight Mass Spectrometer (MR-TOF-MS) at TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN) is an excellent device for performing the necessary mass measurements. This is due to its ability to perform high-precision measurements on short lived species with exceedingly high background contamination. The technique of mass-selective re-trapping has proven a useful tool for measurements near the r-process abundance peaks near A = 82 and 130 due to the ability to reduce background rates by up to four orders of magnitude. A series of experimental campaigns have been conducted in these regions, and a selection of the results will be discussed.

Hosted by Prof. Brodeur