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Title: Investigating Enhanced Thorium Ionization in TIMS Using Re/Pt Porous Ion Emitters

Thermal ionization mass spectrometry (TIMS) is a widely used, benchmark method in the isotopic analysis of actinides relevant to various nuclear and geological fields. Despite significant previous use and inherent advantages, however, poor sample ionization continues to hamper the use of TIMS in the measurement of trace species; actinide ionization efficiencies frequently fall below 0.1 % using traditional instrument sources. Factors leading to poor ionization are compounded in the measurement of several highly refractory metals (e.g. U and Th) that may provide key signatures data in non-proliferation, safeguards and forensics efforts. Herein, a relatively new TIMS ion source strategy, employing porous ion emitters (PIEs) atop traditional filament assemblies, is investigated for the first time as a straightforward means of enhancing the ionization of Th, which is arguably a worst case scenario for TIMS-based actinide measurements. These sources yielded up to 410% greater Th sample utilization, relative to previously published values and in-house measurements collected using traditional methods. Accompanying scanning electron microscopy (SEM) investigations provide preliminary insight into possible mechanisms of PIE functioning and explore the impacts that extended heating have on the constructed source’s structure and composition.
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Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Radioanalytical and Nuclear Chemistry; Journal Volume: 299; Journal Issue: 3
Research Org:
Idaho National Laboratory (INL)
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Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY nuclear forensics; porous ion emitter; thorium; TIMS