During the operation of radioactive ion-beam facilities, such as the recently decommissioned National Superconducting Cyclotron Laboratory (NSCL) and the newly operational Facility for Rare Isotope ...Beams (FRIB), many radioisotopes get deposited along beamlines in components such as in mass-separator slits, fragment catchers, and beam dumps. The techniques to recover the by-product radioisotopes from these components is called ‘solid-phase isotope harvesting’ or ‘isotope mining’ and can help to meet the increasing demand for radioisotopes in a variety of fields. This technique offers a unique approach to access rare isotopes that are often challenging to produce using conventional methods. A comparative analysis with aqueous-phase (harvesting from water) and gaseous-phase (harvesting from gases) methods also shows the distinct advantages of solid-phase harvesting, including simplified chemistry and enhanced flexibility in collection location and material choice.This work comprises four primary aims, each aiming at advancing the understanding and implementation of solid-phase isotope harvesting. The first is to establish the of proof-of-concept for solid-phase isotope harvesting, with a specific focus on the extraction of 88Zr from irradiated tungsten foils. This aim seeks to demonstrate the feasibility and efficacy of solid-phase harvesting, and enables comparison with aqueous-phase harvesting. The second aim involves the harvesting of 172Hf from a tungsten ‘heavy-met’ alloy beam-blocker/beam-dump that was used to stop unused beams at NSCL. The beam blocker was retrieved after the NSCL facility was decommissioned and was chemically processed to extract 172Hf and to develop a 172Hf/172Lu generator. This work utilizes the proof of concept study from the first aim and exhibits harvesting from a decommissioned component. The third aim involves the production of 172Hf from the conventional method of irradiating natural lutetium foil targets at the Brookhaven Linear Isotope Producer (BLIP), coupled with the development of methodologies for extracting 172Hf followed by creation of several 172Hf/172Lu generators. This aim helps to compare radionuclides produced by a conventional technique to those obtained from the isotope harvesting efforts shown in the second aim. The fourth aim demonstrates production and separation of 7Be from natural and enriched boron targets, followed by chemical separation, 7Be source preparation and 7Be beam delivery to users at NSCL. This aim demonstrates the practical application of solid-phase isotope harvesting by producing a specific radionuclide for use in scientific experiments.Collectively, this work describes the radioanalytical techniques and chemical methodologies used in the extraction and purification of embedded radioisotopes from beam-irradiated solid materials of tungsten, boron and lutetium. These four aims have together laid the groundwork for developing robust methodologies to extract and separate long-lived radioisotopes that will accumulate along the FRIB beamline. Ultimately, this work aims to enable solid-phase isotope harvesting on a larger scale at FRIB, when FRIB is operational at full beam power, and at other similar ion-beam facilities. The methods described herein allow harvesting of difficult-to-produce byproduct radionuclides without the need for dedicated beamtime at FRIB.
Production and separation of 7Be for use in an ion source Satija, Samridhi; Domnanich, Katharina A.; Sumithrarachchi, Chandana ...
Applied radiation and isotopes,
September 2024, 2024-09-00, 20240901, Letnik:
211
Journal Article
Recenzirano
Beryllium-7 (7Be) was created by proton irradiation of natural (natB) and enriched (10B) boron targets. The targets were dissolved in nitric acid, and the 7Be was separated from the bulk boron target ...material by cation-exchange chromatography. An average recovery of (99.4 ± 3.7)% was obtained for 6 separations. The purified 7Be sample was placed into a batch-mode ion source to create a 7Be beam that was delivered at an average rate of 5 × 105 pps to end users at the National Superconducting Cyclotron Laboratory.
•Production method for 7Be from proton irradiated natural boron and enriched 10B pellet target without 7Li impurity.•Radiochemical separation method for extracting 7Be from boron pellet target with high purity.•7Be source preparation for use with a batch-mode ion source at heavy-ion radioisotope beam facility.•Pure 7Be4+ ion beam delivered to scientific users.
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.
•Preparation of stable (30Si, 50Cr, 58Fe) and radioactive (26Al, 32Si) source samplesfor the offline beam program at FRIB.•High-yield transformation of the chemical species of 26Al, 50Cr, and 58Fe to compounds that are suitable BMIS source samples.•Effective cation exchange-based method developed to strip the high Na-matrix of the 30Si and 32Si samples.•Reduction of the isobaric 32S contaminant in the 32Si samples by an anion exchange-based procedure.
Tungsten is a commonly used material at many heavy-ion beam facilities, and it often becomes activated due to interactions with a beam. Many of the activation products are useful in basic and applied ...sciences if they can be recovered efficiently. In order to develop the radiochemistry for harvesting group (IV) elements from irradiated tungsten, a heavy-ion beam containing 88Zr was embedded into a stack of tungsten foils at the National Superconducting Cyclotron Laboratory and a separation methodology was devised to recover the 88Zr. The foils were dissolved in 30% hydrogen peroxide, and the 88Zr was chemically purified from the tungsten matrix and from other co-implanted radionuclides (such as 85Sr and 88Y) using strong cation-exchange (AG MP-50) chromatographic resin in sulfuric acid media. The procedure provided 88Zr in approximately 60 mL 0.5 M sulfuric acid with no detectable radio-impurities. The overall recovery yield for 88Zr was (92.3 ± 1.2)%. This proof-of-concept experiment has facilitated the development of methodologies to harvest from tungsten and tungsten-alloy parts that are regularly irradiated at heavy-ion beam facilities.
•Proof-of-concept solid-phase isotope harvesting from tungsten collectors.•Solid-phase isotope harvesting for high recoveries of 88Zr from irradiated W foils.•Solid-phase isotope harvesting has higher recovery efficiency than aqueous-phase harvesting for 88Zr.•Radiochemical methods for extracting trace impurities from tungsten and tungsten-alloy parts were developed.
During routine operation of the Facility for Rare Isotope Beams (FRIB), radionuclides will accumulate in both the aqueous beam dump and along the beamline in the process of beam purification. These ...byproduct radionuclides, many of which are far from stability, can be collected and purified for use in other scientific applications in a process called isotope harvesting. In this work, the viability of 88Zr harvesting from solid components was investigated at the National Superconducting Cyclotron Laboratory. A secondary 88Zr beam was stopped in a series of collectors comprised of Al, Cu, W, and Au foils. This work details irradiation of the collector foils and the subsequent radiochemical processing to isolate the deposited 88Zr (and its daughter 88Y) from them. Total average recovery from the Al, Cu, and Au collector foils was (91.3 ± 8.9) % for 88Zr and (95.0 ± 5.8) % for 88Y, respectively, which is over three times higher recovery than in a previous aqueous-phase harvesting experiment. The utility of solid-phase isotope harvesting to access elements such as Zr that readily hydrolyze in near-neutral pH aqueous conditions has been demonstrated for application to harvesting from solid components at FRIB.
•Proof-of-concept solid-phase isotope harvesting demonstrated at the NSCL.•Solid-phase isotope harvesting for improved recoveries of Zr.•High recoveries of 88Zr and 88Y from Al, Cu, and Au foils irradiated with 88Zr beam.•Provides a framework for harvesting group IV elements from FRIB.
Tungsten is a commonly used material at many heavy-ion beam facilities, and it often becomes activated due to interactions with a beam. Many of the activation products are useful in basic and applied ...sciences if they can be recovered efficiently. In order to develop the radiochemistry for harvesting group (IV) elements from irradiated tungsten, a heavy-ion beam containing
Zr was embedded into a stack of tungsten foils at the National Superconducting Cyclotron Laboratory and a separation methodology was devised to recover the
Zr. The foils were dissolved in 30% hydrogen peroxide, and the
Zr was chemically purified from the tungsten matrix and from other co-implanted radionuclides (such as
Sr and
Y) using strong cation-exchange (AG MP-50) chromatographic resin in sulfuric acid media. The procedure provided
Zr in approximately 60 mL 0.5 M sulfuric acid with no detectable radio-impurities. The overall recovery yield for
Zr was (92.3 ± 1.2)%. This proof-of-concept experiment has facilitated the development of methodologies to harvest from tungsten and tungsten-alloy parts that are regularly irradiated at heavy-ion beam facilities.
