Shizuoka University Conducts World's First Plasma-Driven Permeation Experiment on W-Re Alloys for Fusion Reactors
Key facts
- Shizuoka University Conducts World's First Plasma-Driven Permeation Experiment on W-Re Alloys for Fusion Reactors
- A research group at Shizuoka University has experimentally clarified, for the first time globally, the plasma-driven permeation and retention behavior of hydrogen isotopes in tungsten-rhenium (W-Re) alloys, which are promising materials for fusion reactors. This research provides essential fundamental data for the long-term stable operation and tritium management of fusion reactors.
- Source: PR Times
- Date: June 9, 2026
Direct answer
A research group at Shizuoka University has experimentally clarified, for the first time globally, the plasma-driven permeation and retention behavior of hydrogen isotopes in tungsten-rhenium (W-Re) alloys, which are promising materials for fusion reactors. This research provides essential fundamental data for the long-term stable operation and tritium management of fusion reactors.
- Citation
- Shizuoka University Conducts World's First Plasma-Driven Permeation Experiment on W-Re Alloys for Fusion Reactors (June 9, 2026), PR Times
- Source
- PR Times
- Date
- June 9, 2026
A research group at Shizuoka University has experimentally clarified, for the first time globally, the plasma-driven permeation and retention behavior of hydrogen isotopes in tungsten-rhenium (W-Re) alloys, which are promising materials for fusion reactors. This research provides essential fundamental data for the long-term stable operation and tritium management of fusion reactors.
📋 Article Processing Timeline
- 📰 Published: June 9, 2026 at 11:00
- 🔍 Collected: June 9, 2026 at 11:27 (27 min after Published)
- 🤖 AI Analyzed: June 12, 2026 at 16:51 (77h 23m after Collected)
A research group led by Associate Professor Yasuhisa Oya of the Faculty of Science at Shizuoka University conducted plasma irradiation experiments using the Plasma-Driven Permeation (SUMPPU) device at Shizuoka University. They elucidated the effects of Re and irradiation defects on physical constants related to the plasma permeation and retention behavior in tungsten-tungsten-rhenium (W-Re) alloy samples.
This research achievement was published on May 30, 2026, in the international academic journal "Fusion Engineering and Design" published by Elsevier.
[Research Background]
Fusion power generation, expected to be a next-generation clean energy source, utilizes the energy obtained from the fusion reaction of deuterium (D) and tritium (T). Since the fusion reaction is maintained in a high-temperature plasma state, tungsten (W), with its high melting point and low sputtering yield, is considered a leading candidate for plasma-facing materials that form the reactor wall. During operation, W is exposed not only to high-energy D and T but also to neutrons generated by the D-T reaction. For the realization of fusion reactors, long-term plasma sustainment and strict management of scarce T are indispensable. Therefore, it is necessary to clarify the hydrogen isotope permeation behavior in W under conditions close to actual operation.
However, in W subjected to neutron irradiation, some of it transmutes into rhenium (Re), and irradiation defects are simultaneously introduced. Thus, evaluating the impact of Re and irradiation defects on hydrogen isotope behavior is crucial. Neutron-irradiated samples are radioactive and can only be handled in a limited number of facilities worldwide. By installing the Plasma-Driven Permeation (SUMPPU) device within a controlled area, this research group has been conducting plasma permeation experiments on neutron-irradiated samples, a capability unique globally. In this study, we aimed to elucidate the effects of Re addition by evaluating not only permeation but also retention behavior through D plasma irradiation using SUMPPU.
[Research Results]
In this study, W and W–10%Re alloys were used as samples. To simulate irradiation defects, Fe²⁺ ion irradiation was performed at the Ion Irradiation Research Facility (TIARA), after which the samples were introduced into Shizuoka University's SUMPPU. D plasma permeation experiments were conducted on W and W–Re alloys to evaluate the permeation behavior in W–Re. Furthermore, post-D plasma irradiation, Temperature Programmed Desorption (TPD) was performed to assess the effects of Re and irradiation defects on hydrogen isotope retention behavior.
The results showed that the permeation flux increased in W–10%Re compared to W. Calculating the recombination constant based on the parameters obtained from the experiments revealed that the recombination constant for W–10%Re is smaller than that for W. A decrease in the recombination constant suppresses the release of D from the surface, increasing the D concentration within the sample. This indicates that the increased internal D diffuses to the back surface, leading to a larger permeation flux in W–10%Re.
Furthermore, it was found that Re addition significantly reduces the amount of D retained by suppressing the generation of irradiation defects and reducing D trapping sites. The effects of Re addition were clarified to decrease the recombination constant and suppress the generation of irradiation defects.
[Future Prospects and Ripple Effects]
The insights gained from this research deepen the understanding of hydrogen isotope migration dynamics in W–Re alloys under irradiation environments and will greatly contribute to building the fundamental data required for the development of fusion reactor materials.
[Publication Information]
Journal: Fusion Engineering and Design
Paper Title: Hydrogen isotope permeation and desorption dynamics in W-Re alloys
Authors: Yuzuka Hoshino, Robert Kolasinski, Yasuhisa Oya
DOI: https://doi.org/10.1016/j.fusengdes.2026.115841
Image: SUMPPU device and D plasma irradiation.
This research achievement was published on May 30, 2026, in the international academic journal "Fusion Engineering and Design" published by Elsevier.
[Research Background]
Fusion power generation, expected to be a next-generation clean energy source, utilizes the energy obtained from the fusion reaction of deuterium (D) and tritium (T). Since the fusion reaction is maintained in a high-temperature plasma state, tungsten (W), with its high melting point and low sputtering yield, is considered a leading candidate for plasma-facing materials that form the reactor wall. During operation, W is exposed not only to high-energy D and T but also to neutrons generated by the D-T reaction. For the realization of fusion reactors, long-term plasma sustainment and strict management of scarce T are indispensable. Therefore, it is necessary to clarify the hydrogen isotope permeation behavior in W under conditions close to actual operation.
However, in W subjected to neutron irradiation, some of it transmutes into rhenium (Re), and irradiation defects are simultaneously introduced. Thus, evaluating the impact of Re and irradiation defects on hydrogen isotope behavior is crucial. Neutron-irradiated samples are radioactive and can only be handled in a limited number of facilities worldwide. By installing the Plasma-Driven Permeation (SUMPPU) device within a controlled area, this research group has been conducting plasma permeation experiments on neutron-irradiated samples, a capability unique globally. In this study, we aimed to elucidate the effects of Re addition by evaluating not only permeation but also retention behavior through D plasma irradiation using SUMPPU.
[Research Results]
In this study, W and W–10%Re alloys were used as samples. To simulate irradiation defects, Fe²⁺ ion irradiation was performed at the Ion Irradiation Research Facility (TIARA), after which the samples were introduced into Shizuoka University's SUMPPU. D plasma permeation experiments were conducted on W and W–Re alloys to evaluate the permeation behavior in W–Re. Furthermore, post-D plasma irradiation, Temperature Programmed Desorption (TPD) was performed to assess the effects of Re and irradiation defects on hydrogen isotope retention behavior.
The results showed that the permeation flux increased in W–10%Re compared to W. Calculating the recombination constant based on the parameters obtained from the experiments revealed that the recombination constant for W–10%Re is smaller than that for W. A decrease in the recombination constant suppresses the release of D from the surface, increasing the D concentration within the sample. This indicates that the increased internal D diffuses to the back surface, leading to a larger permeation flux in W–10%Re.
Furthermore, it was found that Re addition significantly reduces the amount of D retained by suppressing the generation of irradiation defects and reducing D trapping sites. The effects of Re addition were clarified to decrease the recombination constant and suppress the generation of irradiation defects.
[Future Prospects and Ripple Effects]
The insights gained from this research deepen the understanding of hydrogen isotope migration dynamics in W–Re alloys under irradiation environments and will greatly contribute to building the fundamental data required for the development of fusion reactor materials.
[Publication Information]
Journal: Fusion Engineering and Design
Paper Title: Hydrogen isotope permeation and desorption dynamics in W-Re alloys
Authors: Yuzuka Hoshino, Robert Kolasinski, Yasuhisa Oya
DOI: https://doi.org/10.1016/j.fusengdes.2026.115841
Image: SUMPPU device and D plasma irradiation.
FAQ
What is the main objective of this research?
To experimentally elucidate the plasma-driven permeation and retention behavior of hydrogen isotopes in tungsten-rhenium (W-Re) alloys, expected to be used as fusion reactor wall materials, and to clarify their effects on physical constants.
Why is the study of W-Re alloys important?
In fusion reactors, wall materials are exposed to harsh plasma environments. Understanding the behavior of hydrogen isotopes is crucial for stable reactor operation, fuel (tritium) management, and predicting material lifespan.
What is unique about the SUMPPU device used in the experiment?
SUMPPU is the world's only device capable of conducting plasma permeation experiments on neutron-irradiated, radioactive samples, enabling research under conditions close to actual operation.
How do the research findings connect to future fusion power generation?
The obtained fundamental data will promote the development of more durable and reliable fusion reactor materials, representing a significant step towards practical application.
What is the effect of rhenium (Re) addition?
It was found that Re addition increases the permeation amount of hydrogen isotopes while significantly reducing their retention within the material, which are advantageous properties for maintaining material integrity.