Scientific Case

Working Group


The High Rigidity Spectrometer (HRS) will be the centerpiece experimental tool of the Facility for Rare-Isotope Beams (FRIB) fast-beam program. The fast-beam program at FRIB has tremendous discovery potential, enabling experiments with beam intensities of few ions per second or less through the luminosity afforded by thick targets. The high magnetic rigidity of the HRS (8 Tm) will match the rigidities for which rare-isotope production yields at the FRIB fragment separator are maximum across the entire chart of nuclei and enable experiments with the most exotic, neutron-rich nuclei available at FRIB.

The figure on the right provides a schematic overview of the scope of the HRS at FRIB and integration example with other detector systems. Items that are within the scope of the HRS project are indicated in bold. Rare isotopes beams are transported from the FRIB fragment separator through the High Acceptance Transport Beam Line to the target position at the HRS. The first element of the HRS after the target station is the sweeper dipole, which diverts charged particles toward a focusing beam line that transports particles to the spectrometer dipoles and the focal plane detectors. The spectrometer dipoles provide the precise exit channel characterization with momentum and particle identification resolutions required for the broad scientific program with the HRS.

Also shown are the Gamma-Ray Energy Tracking Array (GRETA) and the Modular Neutron Array (MoNA-LISA). The HRS will run in combination with these and other auxiliary detection systems.