FRIB, East Lansing, Michigan, USA
The Facility for Rare Isotope Beams (FRIB) was fully commissioned in early 2022, and the operation for physics experiments started shortly thereafter. Various ion beam species have been accelerated up to 240 MeV/u and delivered to the target. During the first year of user operations, the FRIB provided 4252 beam hours with 91% availability for nuclear science. In addition, FRIB delivered about 1000 hours of various ion beam species at beam energies up to 40 MeV/u for single-event experiments. Typically, the experiments with a specific species rare isotope beam last a week or two. Each experiment requires a different primary beam species with specific energies. The primary beam power has been gradually increased from 1 kW to 10 kW over the past 1.5 years. The Accelerator Physics (AP) group develops high-level physics applications to minimize machine set-up time. Focuses include identifying beam halo sources, controlling emittances of multiple-charge-state beams, and studying the beam loss mechanisms to prepare for the ultimate 400 kW operation. This paper discusses the experience and challenges of operating a high-power CW heavy ion accelerator.
WEC2I2
FRIB, East Lansing, Michigan, USA
ANL, Lemont, Illinois, USA
The charge stripping of a primary beam in heavy ion accelerators is an essential process to achieve a high beam energy at targets. The Facility for Rare Isotope Beams (FRIB), which aims at achieving an ultimate primary beam power of 400 kW, has charge strippers where the primary beam energy reaches 17-20 MeV/u in the driver linac. Because of the unprecedented intensity of heavy ion beams to achieve the 400 kW power, ultra-high thermal load and radiation damage to the charge stripping material will make it practically useless if a solid is used. To overcome these challenges, FRIB chose liquid lithium as a revolutionary stripper material, which is a superior heat remover and free from radiation damage. FRIB¿s liquid lithium charge stripper (LLCS) produces a liquid lithium thin film flowing at 60 m/s, which gives a relatively flat film with a thickness of 10-20 ¿m (0.5-1.0 mg/cm2). We also have a carbon foil charge stripper (CCS), which is a carbon foil that rotates and moves vertically to spread thermal and radiation damage. We have demonstrated that both the CCS and LLCS can support 5-kW-at-target Xe primary beam operations. We will discuss their performance in this paper.
FRIB, East Lansing, Michigan, USA
INFN/LNL, Legnaro (PD), Italy
Fermilab, Batavia, Illinois, USA
TRIUMF, Vancouver, Canada
ANL, Lemont, Illinois, USA
LBNL, Berkeley, USA
After project completion on scope, on cost, and ahead of schedule, the Facility for Rare Isotope Beams began operations for scientific users in May of 2022. The ramp-up to a beam power of 400 kW is planned over a six-year period; 1 kW was delivered for initial user runs from in 2022, and 5 kW was delivered as of February 2023. Test runs with 10 kW 36Ar and 48Ca beams were conducted in July 2023. Upgrade plans include doubling the primary-beam energy to 400 MeV/nucleon for enhanced discovery potential (¿FRIB 400¿). This talk reports on the strategic plans towards high power operations emphasizing challenges and resolutions in beam-interception devices and targetry systems, radiation protection and controls, and legacy system renovation and integration.