Gas cell studies of thorium using filament dispensers at IGISOL

Abstract

Filament-based dispensers of thorium have been investigated at the IGISOL facility, Jyväskylä, for potential use as a thorium ion source for future collinear laser spectroscopy experiments. Several different filaments were manufactured in the Institute of Atomic and Subatomic Physics of TU Wien, with 232 Th and 229 Th prepared on tantalum substrates either by drying thorium nitrate solution or via molecular plating, while adding a layer of zirconium for oxide reduction. The filaments were characterized in a helium-filled gas cell by performing selective and efficient in-gas-cell resonance laser ionization and by analyzing the resulting ion beams by mass spectrometry. Additionally, the in-gas-cell laser ionization process of thorium was further characterized by wavelength scans, saturation measurements and by recording the temporal behavior of extracted ion pulses. Although an ion source was successfully created with mass-separated intensities over 10 6 ions/s, the required high filament temperature resulted in significant contributions from interfering impurities and deterioration of the filament structure.

Opportunities for Fundamental Physics Research with Radioactive Molecules

“…Further reactions then occur with water molecules, via a thermolecular association reaction, leading to hydrate attachments to the oxide molecule. Very similar chemistry has been observed in thorium (Pohjalainen, Moore, Geldhof, Rosecker, Sterba and Schumm, 2020), and it would be expected in other reactive actinide elements. It is noteworthy that these molecules do not easily break up during beam transportation, and would therefore be available for study.…”

“…The monoatomic yields were sufficient for high-resolution collinear laser spectroscopy, resulting in measurements of mean-square charge radii and hyperfine structure (Voss et al, 2017). Similarly, a thorium ion source has been developed using thorium dispensers fabricated at the Institute of Atomic and Subatomic Physics (ATI) of TU Wien (Pohjalainen, Moore, Geldhof, Rosecker, Sterba and Schumm, 2020).…”

Simultaneously Recovery of Thorium and Tungsten through Hybrid Electrolysis–Nanofiltration Processes

“…Utilization of tungsten residue [1] Tungsten resources and potential extraction [3] Recovery of W(VI) from wolframite ore using new synthetic Schiff-based derivative [17] Extraction of sodium tungstate from tungsten ore [18] Progress in sustainable recycling and circular economy of tungsten carbide [19] Tungsten resources and potential extraction from mine waste [20] Thorium Recovery and transport of thorium (IV) through polymer inclusion membrane [9] Process for the separation of U(VI), Th(IV) from rare earth elements by using ionic liquid Cyphos IL 104. [11] Thorium removal, recovery, and recycling [12] Polymeric materials for rare earth element recovery [13] Highly efficient adsorbent to remove thorium ions [15] Impacts of uranium-and thorium-based fuel cycles with different recycle options [16] The interest in thorium is argued both because it is a material with huge potential for energy generation, including nuclear energy [31][32][33][34][35][36][37][38][39][40], but also because, although it is radioactive, it is the object of some domestic applications that capitalize on the resistance to high temperatures of thorium dioxide (lamps, shields, crucibles, and welding electrodes) [41] or its special refractive index (lenses, glasses, and high-resolution optoelectronic apparatus) [12]. It becomes obvious that with the use of these materials, but also because thorium has a natural abundance similar to that of lead [42], it will be found in urban industrial waste arriving in various forms on municipal integrated processing platforms [43].…”

“…The interest in thorium is argued both because it is a material with huge potential for energy generation, including nuclear energy [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ], but also because, although it is radioactive, it is the object of some domestic applications that capitalize on the resistance to high temperatures of thorium dioxide (lamps, shields, crucibles, and welding electrodes) [ 41 ] or its special refractive index (lenses, glasses, and high-resolution opto-electronic apparatus) [ 12 ]. It becomes obvious that with the use of these materials, but also because thorium has a natural abundance similar to that of lead [ 42 ], it will be found in urban industrial waste arriving in various forms on municipal integrated processing platforms [ 43 ].…”

Thorium Removal, Recovery and Recycling: A Membrane Challenge for Urban Mining

“…Thorium, and especially thorium dioxide, has found relatively numerous applications for a radioactive element, even if this radioactivity is weak [ 21 , 22 , 23 ]. As various and unexpected, with many having been abandoned, the applications of thorium are so common ( Figure 1 ) that they have become dangerous [ 21 ], especially since after the use of various materials and under the conditions of inattention in recycling or selective collection, thorium ends up in the environment [ 22 ].…”