Design of a Spectroscopy Experiment for All Hydrogen Isotopologues in the Gaseous, Liquid, and Solid Phase

An integral part of the fuel cycle of future fusion facilities is the isotope separation system (ISS). The Tritium Laboratory Karlsruhe (TLK) is currently developing a system to monitor the concentration of all six hydrogen isotopologues Q₂ (H₂, HD, D₂, HT, DT, T₂) in the liquid phase in the cryogenic distillation process of the ISS.

Liquid inactive Q₂ were already successfully analyzed under cryogenic conditions via infrared (IR) absorption spectroscopy and calibration data for D₂ is provided by previous experiments at TLK. The new experiment T₂ApIR (Tritium Absorption Infrared Spectroscopy Experiment) is designed to be fully tritium compatible to perform a complete calibration of the IR absorption measurement system with all six hydrogen isotopologues in the liquid phase under conditions similar to the ISS. This provides a unique non-invasive, inline and real-time measurement system for isotopologic concentration determination, ready for implementation in the cryogenic distillation column.