Cyogenic Thermal Conductivity Measurements of Yb:YAG Ceramics

Thermal conductivity of 9.8 at% Ytterbium-doped Yttrium Aluminum Garnet (Yb:YAG) ceramics has been measured by three systems at Commissariat à l'Énergie Atomique et aux énergies alternatives (CEA Paris-Saclay) and at the National Institute for Fusion Science (NIFS). For accurate measurements, thermal impedances in thermal systems should be negligibly small. However, each system includes some thermal impedance in a heat flow path. This paper describes that thermal conductivity of the 9.8% doped Yb:YAG ceramics and discusses the compensation method for thermal impedance in each system.