Speaker
Description
CARIBU (CAlifornium Rare Isotope Breeder Upgrade) has been operating at the Argonne National Laboratory’s ATLAS facility for over a decade, and it is able to provide neutron-rich isotopic beams harvested from the fission fragment yield following the decay of a 252Cf source of ~1 Ci. These isotopes can be transported to a low-energy experimental hall and their ground state and decay properties studied, or they can be sent to an EBIS ion-source and reaccelerated by ATLAS and delivered to the various target stations. A robust program of research has utilized this facility over the last 10 years, concentrating on precision mass measurements, decay studies and Coulomb excitation measurements of re-accelerated beams. The program has been limited in available beam intensities due to targetry issues involving the 252Cf source. An upgrade to the facility is now underway to increase the radioactive beam capabilities of the ATLAS/CARIBU accelerator facility by the installation of a new source of fission fragments in CARIBU to provide reliably more intense beams of short-lived neutron-rich isotopes. These isotopes will be obtained from the neutron-induced fission of 235U in a thin foil located in a large gas catcher from which the radioactive ions will be extracted and transferred to the EBIS charge breeder before acceleration in the ATLAS superconducting linac. The technique keeps the fast, universal, and efficient features of CARIBU while removing the difficulties associated with obtaining a thin 252Cf source. It will increase the accelerated neutron-rich beam intensities by 10x due to increased fission yield into the gas catcher. This upgrade will enhance the reach of ATLAS/CARIBU and its world-unique capabilities to study neutron-rich nuclei. It will also help advance technologies critical for the FRIB facility. In this presentation, the facility as it now stands and how it will transform will be reviewed. In addition, highlights from the physics program will be given as well as examples of measurements which will be possible once the upgrade in completed will be presented.
