Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

Area of Science:

• Materials Science
• Nuclear Engineering
• Plasma Physics

Background:

• Understanding irradiation damage is crucial for developing advanced nuclear fission and fusion reactors.
• Ion-irradiation is a valuable tool for simulating high damage doses in reactor materials without inducing radioactivity.
• Mechanical properties of ion-irradiated materials have been studied, but thermal transport properties remain largely unexplored due to measurement challenges.

Purpose of the Study:

• To investigate the thermal transport properties of ion-implanted tungsten, a material used for nuclear fusion armor.
• To develop and demonstrate a non-contact measurement technique for thermal diffusivity in thin, ion-implanted layers.
• To understand how alloying and retained gases affect the thermal properties of irradiated tungsten.

Main Methods:

• Utilized ion-irradiation to create controlled damage layers in tungsten samples.
• Employed non-contact thermal diffusivity measurements to assess the thermal transport properties of the damaged layers.
• Developed and applied modeling approaches to interpret the experimental results.

Main Results:

• Demonstrated successful non-contact measurement of thermal diffusivity in ion-implanted tungsten.
• Observed significant reductions in thermal diffusivity due to alloying with transmutation elements.
• Found that retained gas interactions with defects also dramatically decrease thermal diffusivity.
• Validated these findings with developed modeling approaches.

Conclusions:

• Alloying and retained gases substantially degrade the thermal diffusivity of ion-irradiated tungsten.
• The developed measurement technique is suitable for evaluating thermal properties of thin irradiated layers.
• These findings are critical for the design and safety of future fusion power plants, particularly for armor components.