Spatially localized measurement of thermal conductivity using a hybrid photothermal technique

摘要

A photothermal technique capable of measuring thermal conductivity with micrometer lateral resolution is presented. This technique involves measuring separately the thermal diffusivity, D, and thermal effusivity, e, to extract the thermal conductivity, k = (e~2/D)~(1/2). To generalize this approach, sensitivity analysis is conducted for materials having a range of thermal conductivities. Application to nuclear fuel is consider by performing experimental validation using two materials (CaF_2 and SiO_2) having thermal properties representative of fresh and high burnup nuclear fuel. The measured conductivities compare favorably with literature values.