Tungsten is foreseen as a plasma-facing material in a fusion reactor, which provides an intense neutron radiation environment. The CRP will enhance the knowledge base on effects of neutron and surrogate irradiation upon tungsten and tungsten alloy microstructure and thereby upon surface erosion and upon trapping and transport of tritium in tungsten-based plasma-facing materials.
The overall objective of the CRP is to support fusion plasma and fusion materials modelling and planning and design efforts towards DEMO and a Fusion Power Plant through the enhancement of the knowledge base on properties of tungsten as a plasma-facing material in a fusion nuclear environment, and thereby to contribute to the development of fusion energy generation.
To perform coordinated experiments and computations to improve the knowledge base on the influence of tungsten microstructure on erosion and tritium retention and transport properties.
To increase capabilities of Member States to undertake fusion plasma and fusion materials modelling and to support planning and design efforts in Member States towards DEMO and a Fusion Power Plant through the enhancement of the knowledge base on properties of tungsten as a plasma-facing material in a fusion nuclear environment, and thereby to contribute to the development of fusion energy generation.
To inventorise knowledge about effects of neutron irradiation and charged particle surrogate irradiation on the microstructure of tungsten-based plasma-facing materials.
To synthesize new information, extrapolate to relevant fusion neutron fluence, and provide best expert estimates and uncertainties for erosion and tritium retention for tungsten-based materials in a fusion reactor environment.
To inventorise knowledge about the relation between tungsten microstructure after irradiation and plasma-material interaction properties for erosion, tritium retention and tritium migration.
To perform coordinated experiments and computations (based on quantum theory and molecular dynamics) to improve the knowledge base on effects of irradiation upon tungsten microstructure.
1. To inventorise knowledge about effects of neutron irradiation and charged particle surrogate irradiation on the microstructure of tungsten-based plasma-facing materials.2. To inventorise knowledge about the relation between tungsten microstructure after irradiation and plasma-material interaction properties for erosion, tritium retention and tritium migration.3. To perform coordinated experiments and computations (based on quantum theory and molecular dynamics) to improve the knowledge base on effects of irradiation upon tungsten microstructure.4. To perform coordinated experiments and computations to improve the knowledge base on the influence of tungsten microstructure on tritium retention and tritium transport properties.5. To synthesize new information, extrapolate to relevant fusion neutron fluence, and provide best expert estimates and uncertainties for plasma-material interaction properties (especially tritium retention and tritium transport) for tungsten-based materials in a fusion reactor environment.
Enhancement of the global knowledge base on the formation and behaviour of irradiated tungsten, with a particular emphasis on its properties with respect to the retention of hydrogen, an important issue for the successful operation of a future generation of experimental nuclear fusion reactors. Collaborative activities between participants generated robust benchmarks of theoretical models against experiment, studied in depth the methodology of using ion irradiation as a proxy for neutrons, and issued recommendations on best-practice for thermal desorption spectroscopy experimental procedures.
Tungsten is foreseen as a plasma-facing material in many concepts for a nuclear fusion reactor, and indeed is used in the divertor of the ITER experiment, because of its high melting point and low propensity to absorb tritium. However, under the high neutron fluxes expected in an operating device, its crystal structure is damaged and its properties with respect to the transport and retention of tritium change. In the absence of adequate experimental data, the data collected and evaluated within this CRP concerning theoretical modelling, experimental with proxy ion-irradiation are a valuable resource for Member States in their efforts to progress nuclear fusion energy research.