Accelerator commissioning and rare isotope identification at the Facility for Rare Isotope Beams

Abstract

In 2008, Michigan State University was selected to establish the Facility for Rare Isotope Beams (FRIB). Construction of the FRIB accelerator was completed in January 2022. Phased accelerator commissioning with heavy ion beams started in 2017 with the normal-conducting ion source and radio-frequency quadrupole. In April 2021, the full FRIB driver linear accelerator (linac) was commissioned, with heavy ion beams accelerated to energies above 200 MeV/nucleon by 324 superconducting radiofrequency (SRF) resonators operating at 2 K and 4 K with liquid-helium cooling. In preparation for high-power operation, a liquid lithium charge stripper was commissioned with heavy ion beams up to uranium-238, followed by the simultaneous acceleration of multiple-charge-state heavy ion beams to energies above 200 MeV/nucleon. In December 2021, selenium-84 was produced with the FRIB target using a krypton-86 primary beam, demonstrating FRIB’s capability for scientific discovery.

Accelerator and beam physics challenges in support of FRIB experiments

“…The FRIB driver linac is capable of accelerating uranium ions to 200 MeV/u and higher energies for lighter ions with 400 kW power on the target [1]. The progress with the FRIB linac construction, development, and commissioning was reported in multiple publications; for example, [2,3,4,5]. The 400-kW ion beams will be delivered to a thin fragmentation target which is followed by a large-acceptance high-resolution fragment separator (FS).…”

Technological developments and accelerator improvements for the FRIB beam power ramp-up

“…The Facility for Rare Isotope Beams (FRIB) was completed in April 2022, on scope, on cost, and ahead of the baseline schedule established about 10 years ago [1]. The ramp-up to the ultimate design beam power of 400 kW is planned over a six-year period; 1 kW was delivered for initial user runs starting in May 2022; 5 kW was delivered in February 2023.…”