NuCARIBU: An upgrade for the CARIBU facility at the Argonne Tandem Linac Accelerator System

The Californium Rare Isotope Breeder Upgrade (CARIBU) facility is changing the mechanism for creating neutron-rich fission products. Spontaneous fission from a 252Cf source has provided beams to support the low energy and accelerated-beams ATLAS programs. 252Cf has a 2.65-year half-life, requiring the source to be replaced every three years to maintain high beam intensities. Fabricating an appropriately thin 252Cf source to efficiently release the fission products has been challenging. The solution to these problems is nuCARIBU, a new system that provides neutron-induced fission on actinide foils. The Best Cyclotron B6P System (6-MeV proton beam at 0.5mA) is chosen, utilizing a multi-cusp negative ion source extracting into a cyclotron, which uses carbon foils to strip the H- ions to protons. These protons are delivered to a 7Li target to produce neutrons. The fast neutrons are moderated to thermal energies to induce fission in an actinide foil, providing neutron-rich fission products. These subsystems are described in detail along with comparisons between the current CARIBU facility and the presented nuCARIBU facility. This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No.