Exploitation of thermal gradients for investigation of irradiation temperature effects with charged particles
The effects of radiation damage on materials are strongly dependant on temperature, making it arguably the most significant parameter of concern in nuclear engineering. Owing to the challenges and expense of irradiating and testing materials, material property data is often limited to few irradiation conditions and material variants. A new technique has been developed which enables the investigation of radiation damage of samples subject to a thermal gradient, whereby a wealth of data over a range of irradiation temperatures is produced from a single irradiation experiment. The results produced are practically inaccessible by use of multiple conventional isothermal irradiations. This technique has been demonstrated with a precipitation-hardened copper alloy (CuCrZr), as a challenging example due to its high thermal conductivity. Irradiation of a sample incorporating a linear temperature gradient between 125 and 450 °C was demonstrated. Subsequent micro-scale post irradiation characterisation (nanoindentation, transmission electron microscopy and atom probe tomography) highlight the capability to observe mechanical and microstructural changes over a wide range of irradiation temperatures. Initial results demonstrate excellent reproducibility and compare well with data from isothermal neutron irradiation studies. The technique can be used to quickly generate qualitative assessments of novel materials and investigate fundamental material behaviour.