Gas cell studies of thorium using filament dispensers at IGISOL

[摘要] Filament-based dispensers of thorium have been investigated at the IGISOL facility, Jyvaskyla, 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 Th-232 and Th-229 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.

[发布日期] 2020-12-01

[关键词] Ion source;Thorium;Resonance laser ionization;Gas cell