MOPA29
ANL, Argonne, Illinois, USA
Luisiana State University, Department of Physics and Astronomy, Baton Rouge, USA
At the ATLAS we are developing a fast, compact particle detector to aid the tuning of low intensity beam constituents with relatively high intensity (>100x) contaminants. These conditions are regularly encountered during radioactive ion beam (RIB) production via the in-flight method, or when charge breeding fission fragments from CARIBU. Presently silicon barrier detectors (SBD) are used for mass identification. However, the total acceptable SBD rate is limited to ~1000 pps, so the signal rate from any minority constituents 100x less intense is typically much too slow to enable meaningful accelerator optimization. In addition, the performance of SBDs deteriorates after a relatively low integrated flux. The in-flight method of RIB production produce beams with energies 5-15 MeV/u and masses less than 35 AMU, while beams from CARIBU are typically 80 < A < 160 and accelerated to energies of 4-10 MeV/u. Our goal is to build a radiation hard detector capable of Z and A identification with ~5% energy resolution at a total rate of 105 pps over these energy and mass ranges. The conceptual design of the detector and simulated performance results will be presented.
WEA2I01
ANL, Argonne, Illinois, USA
The efficient and rapid production of a high-quality, pure beam of highly charged ions is at the heart of any radioactive ion beam facility. An ECR charge breeder, as part of the Californium Rare Ion Breeder Upgrade (CARIBU) program at Argonne National Laboratory, was developed to fulfill this role. The charge breeding efficiency and high charge state production of the source are at the forefront of ECR charge breeders, but its overall performance as part of the accelerator system is limited by a pervasive stable ion background and relatively long breeding times. Steps have been taken to reduce the level of background contamination but have met with limited success. As such, an EBIS charge breeder has been developed and is now running in an off-line configuration. It has already demonstrated good breeding efficiencies, shorter residence times, and reduced background, and it is scheduled to replace the ECR charge breeder in late 2015. The resultant change in duty cycle and time structure necessitates changes to the overall facility operation. The experiences with these breeders their strengths, their weaknesses, and the possible paths to further improvement - will be discussed.
