Publications by authors named "J D Despotopulos"

Radioactive arsenic (As) isotopes are of growing interest for applications in nuclear medicine, national security, and environmental research. Recent efforts at the Facility for Rare Isotope Beams (FRIB) have focused on aqueous harvesting of selenium-72,73 (Se) and their daughter isotopes, arsenic-72,73 (As), which are particularly valuable for medical applications and nuclear data studies, respectively. Both conventional isotope production and harvesting methods require chemical separations to purify radioactive As from parent and co-produced Se radioisotopes.

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Article Synopsis
  • - The experiment at Lawrence Berkeley National Laboratory aimed to produce a superheavy element with an atomic number of 114 or greater by bombarding an actinide target with a ^{50}Ti beam.
  • - Using the Berkeley Gas-filled Separator, researchers successfully isolated and implanted produced Livermorium (Lv) ions into a high-tech detector system, observing two decay chains linked to ^{290}Lv.
  • - The measured production cross-section of the process was 0.44 picobarns at a specific energy, marking the first published evidence of superheavy element production near the "island of stability" with this method, paving the way for future discoveries beyond element Z=118.
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Advanced used nuclear fuel (UNF) reprocessing strategies are limited by the complex radiochemical separations and engineering required to achieve the separation of actinides (An) from neutron scavenging lanthanides (Ln). The accessibility of the hexavalent oxidation state for the actinides (U - Am) provides a pathway to achieving a group hexavalent actinide separation from the trivalent lanthanides and Cm. The solid oxidant and ion exchanger, sodium bismuthate (NaBiO), has been demonstrated to quantitatively oxidize and separate Am from trivalent Cm in a column chromatographic system.

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Since the National Ignition Facility (NIF) was commissioned in 2009, radiochemical techniques have been viewed as a potential method for diagnosing the performance of an NIF fusion shot. Radiochemical methods can also be used in conjunction with NIF shots to measure nuclear reaction cross sections in regimes that are inaccessible at accelerator facilities and can provide a route to produce radioactive tracer materials that can be used for other applications. This review presents the current status of radiochemical diagnostics at the NIF.

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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.

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