Abstract
A new combination diagnostic as a hydrogen recycling monitor in harsh conditions is proposed. Combining permeation membrane probe with a Langmuir probe provides a possibility to measure both atomic and ionic hydrogen fluxes to plasma facing components. A brief overview of permeation probes is given. The range of measurable H fluxes is from 1016 to more than 1020 Hm−2s−1. Time response of the permeation probe is ∼0.1−0.5 s. A method to address disadvantages of permeation probes is proposed. This includes an introduction of a preparation chamber for Ar-plasma cleaning of the membrane and absolute calibration with a visible spectroscopy. The hydrogen recombination coefficient, evaluated in such calibration, is ku=5.9×10−30m4s−1, which agrees well with previous research.
Original language | English |
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Article number | 113462 |
Journal | Fusion Engineering and Design |
Volume | 189 |
DOIs | |
State | Published - Apr 2023 |
Funding
This work has been financially supported by the NIFS Collaboration Research Program, Japan ( NIFS13KUTR087 , NIFS22KUTR173 ). The authors are grateful for the support of QUEST team.
Keywords
- Atomic hydrogen
- Hydrogen
- PdCu
- Permeation
- Steady state tokamak operation