FRIB, East Lansing, Michigan, USA
MSU, East Lansing, Michigan, USA
ANL, Lemont, Illinois, USA
The Facility for Rare Isotope Beams (FRIB) at Michi-gan State University is a 400 kW heavy ion linear accel-erator. Heavy ion accelerators normally include a charge stripper to remove electrons from the beams to increase the charge state of the beams thus to increase the energy gain. Thin carbon foils have been the traditional charge stripper but are limited in power density by the damage they suffer (sublimation and radiation damage) and con-sequently short lifetimes. Because of the high beam pow-er, FRIB had decided to use a liquid lithium charge strip-per (LLCS), a self-replenishing medium that is free from radiation damage. FRIB recently commissioned a LLCS with heavy ion beams (36Ar, 48Ca, 124Xe and 238U beams at energies of 17-20 MeV/u). Since there had been no exper-imental data available of charge stripping characteristics of liquid lithium, this was the first demonstration of charge stripping by a LLCS. The beams were successfully stripped by the LLCS with slightly lower charge states than the carbon foils of the same mass thickness. The LLCS started serving the charge stripper for FRIB user operations with a backup rotating carbon foil charge stripper. FRIB has become the world’s first accelerator that utilizes a LLCS.
FRIB, East Lansing, Michigan, USA
The Facility for Rare Isotope Beams (FRIB), a major nuclear physics facility for research with fast, stopped and reaccelerated rare isotope beams, was successfully commissioned and is in operation. The acceleration of Xe, Kr, and Ar ion beams above 210 MeV/u using all 46 cryomodules with 324 superconducting cavities was demonstrated. Several key technologies were successful-ly developed and implemented for the world’s highest energy continuous wave heavy ion beams, such as full-scale cryogenics and superconducting radiofrequency resonator system, stripping of heavy ions with a thin liquid lithium film, and simultaneous acceleration of multiple-charge-state heavy ion beams. In December 2021, we demonstrated the production and identification of 84Se isotopes and, in January 2022, commissioned the FRIB fragment separator by delivering a 210 MeV/u argon beam to the separator’s focal plane. The first two user experiments with primary 48Ca and 82Se beams have been successfully conducted in May-June 2022.
FRIB, East Lansing, Michigan, USA
The Facility for Rare Isotope Beams (FRIB) has been commissioned, with rare isotopes first produced in December 2021 and first user experiments conducted in May 2022. The FRIB driver linear accelerator (linac) uses 6 room temperature cavities, 324 superconducting cavities, and 69 superconducting solenoids to accelerate ions to more than 200 MeV/nucleon. Because of the large scale, automation is essential for reliable linac operation with high availability. Automation measures implemented during linac commissioning include turn-on of the cavities and solenoids, turn-on and fast recovery for room temperature devices, and emergency shut down of linac devices. Additional automated tasks include conditioning of multipacting barriers in the cavities and calibration of the control valves for the pneumatic tuners. To ensure a smooth transition to operations, we are currently working on real-time health monitoring of the linac cryomodules, including critical signals such as X-ray levels, RF coupler temperatures, and cryogenic parameters. In this paper, we will describe our automation procedures, the implementation details, and the experience we gained.