Deuterium retention in recrystallized tungsten exposed to high-flux plasma with fluences up to 1 × 1029 m−2
Plasma fluence at the divertor of a future magnetic confinement fusion device can accumulate up to ∼10 ^28 –10 ^29 m ^−2 per year. Yet hydrogen isotope (HI) retention under such high-fluence plasma exposure has been rarely reported. To investigate deuterium (D) retention in tungsten (W) exposed to s...
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| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
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| Series: | Nuclear Fusion |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1741-4326/adc286 |
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| Summary: | Plasma fluence at the divertor of a future magnetic confinement fusion device can accumulate up to ∼10 ^28 –10 ^29 m ^−2 per year. Yet hydrogen isotope (HI) retention under such high-fluence plasma exposure has been rarely reported. To investigate deuterium (D) retention in tungsten (W) exposed to such high-fluence plasma, a series of high-flux D plasma exposures were preformed using recrystallized W samples at ∼500 K in Magnum-PSI. The highest fluence achieved was ∼1 × 10 ^29 m ^−2 . Surface morphology observations indicate an initial increase in the number of blisters at the sample surface with increasing fluence, followed by saturation at ∼1 × 10 ^29 m ^−2 . Multiple bursts of blisters with open cracks or edges were observed under the two highest fluences of ∼1 × 10 ^28 m ^−2 and ∼1 × 10 ^29 m ^−2. 3 He nuclear reaction analysis (NRA) shows a maximum D concentration up to 0.012 at.fr., distributed within the first 4 μ m from the sample surface under the highest fluence. D retention, as measured by NRA and thermal desorption spectroscopy, tends to saturate with increasing fluence. Simulations of D _2 thermal desorption, performed using the TMAP rate equation code, show a maximum D trapping depth of ∼10 μ m, consistent with the defect depth profile revealed by transmission electron microscopy. D retention saturation observed in this work is attributed to the sample surface morphology modifications and the saturation of plasma-induced defects. This investigation provides a valuable reference for understanding the evolution of total HI retention in W under high-fluence plasma exposure in future fusion devices. |
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| ISSN: | 0029-5515 |