Preparation of stable and long-lived source samples for the stand-alone beam program at the Facility for Rare Isotope Beams.

At the Facility for Rare Isotope Beams (FRIB), an oven-ion source combination was used to create rare isotope beams in support of the stand-alone user beam program of the ReAccelerator (ReA) facility. This ion source, called Batch-Mode Ion Source (BMIS), was loaded with enriched stable nuclides (30Si, 50Cr, and 58Fe) and long-lived radionuclides (26Al, 32Si). The introduced samples, herein designated as source samples, were thermally volatilized in the BMIS oven, and then ionization was used to generate the required beams. Owing to the different chemical behavior of the used samples, it was important to tailor the sample loading process for each desired beam species. An important parameter here is the volatility of the introduced species, which influences the adequate release of the isotope of interest. Additionally, any co-present, volatile components will affect the ion yields of the desired isotope, while isobaric contaminants will decrease the beam purity. To manufacture isotope source samples that meet these characteristics, various chemical methodologies were developed. All prepared samples were successfully used in BMIS to deliver beams for various user beam experiments. The here-established sample preparation techniques will greatly aid future efforts in developing offline rare-isotope beams.

Proof-of-concept studies of novel protocols for producing highly pure 48V from a 48Cr/48V generator.

The quest to improve the quality of nuclear data, such as half-lives, transition yields, and reaction cross-sections, is a shared endeavor among various areas of nuclear science. 48V is a vanadium isotope for which experimental data on neutron reaction cross-sections is needed. However, traditional isotope production techniques cannot produce 48V with high enough isotopic purity for some of these measurements. "Isotope harvesting" at the Facility for Rare Isotope Beams (FRIB) is a new isotope production technique that could potentially yield 48V with the necessary purity for such studies. In this case, 48Cr would be collected and allowed to generate 48V that can be separated from undecayed 48Cr to yield highly pure 48V. Thus, any protocol for producing pure 48V via isotope harvesting would involve utilizing a separation technique that can effectively separate 48Cr and 48V. In this study, the radiotracers 51Cr and 48V were used to develop possible radiochemical separation methodologies, which can be translated to obtain high purity 48V via this novel isotope production method. The developed protocols utilize either ion exchange or extraction chromatographic resins. Separations of 51Cr and 48V with AG 1-X8 anion exchange resin respectively resulted in recoveries of 95.6(26)% and 96.2(12)% with radionuclidic purities of 92(2)% and 99(1)%. An even more effective Cr and V separation was obtained with an extraction chromatographic resin (TRU resin) and 10 M HNO3 loading solution. Here, 51Cr and 48V respectively had recoveries of 94.1(28)% and 96.2(13)% with high radionuclidic purities (100(2)% and 100(1)%) in small volumes (8.81(8) mL and 5.39(16) mL). This study suggests that, to maximize the yield and isotopic purity of 48V, the best production protocol would involve utilizing two separations with TRU resin and 10 M HNO3 to isolate 48Cr and purify the generated 48V.