Thermal properties of 2G coated conductor cable materials

• Coated Conductor Rutherford superconducting cable concept is discussed.
• Superconducting cable will consist of different structural materials.
• Thermal properties of structural materials have been measured at low temperatures.
• Different thermal expansion of used materials can cause technical problems.

The development of superconducting high current cable concepts for magnets to be used in the future fusion energy reactors is highly demanding. One of such concepts for Coated Conductor Rutherford Cables (CCRCs) using Roebel high temperature superconducting subcables as strands was recently presented. The thermal properties of structural materials play an important role for the stability of the Rutherford cables. Namely, the thermal conductivity is an important material property, e.g., for the prediction of quench propagation in the conductor. Moreover, the thermal expansion of individual components of a Rutherford cable should be in the same range to avoid mechanical stress during cool down. In this work, we present and discuss results of the thermal conductivity and expansion measurements of the structural materials used for the production of the Rutherford cables in the temperature range from 4 K to 300 K.