CARIBU: a new facility for the study of neutron-rich isotopes
G. Savard
Argonne National Laboratory and University of Chicago, USA
The Californium Rare Ion Breeder Upgrade (CARIBU) of the ATLAS superconducting linac facility provides low energy and reaccelerated neutron-rich radioactive beams to address key nuclear physics and astrophysics questions. These beams are obtained from fission fragments of a 252Cf source, thermalized and collected into a low-energy particle beam by a helium gas catcher, mass analyzed by an isobar separator, and charge breed to higher charge states for acceleration in ATLAS.  The method described is fast and universal and short-lived isotope yield scale essentially with Californium fission yields.  The facility has ramped up with first operation with a weaker 2.5 mCi source and now a 100 mCi source which has yielded extracted low-energy mass separated radioactive beams at intensities in excess of 100000 ions per second. Radioactive beams have been charge bred with an efficiency of about 12% and reaccelerated to 6 MeV/u.  Commissioning results, together with the results from first astrophysics experiments at CARIBU using the beams from the 100 mCi source will be presented.  The final 1 Ci source has been fabricated and its installation is in preparation.
This work was supported by the US DOE, Office of Nuclear Physics, under contract DE-AC02-06CH11357.