Thermal meter design for testing performance of high vacuum multi-layer insulation based on liquid helium temperature

A thermal meter for testing multi-layer thermal insulation materials in the liquid helium temperature was designed． Structural design，mechanical analysis and theoretical calculation of heat leakage were performed on the thermal meter to verify the reliability． The results ofmechanical analysis show that the maximum displacement deformation of the thermal meter is 0． 16mm，which is located at the bottom of the lower protective vessel; the maximum stress is 49 MPa，which is located at the top of the cooled shield． The theoretical calculation of heat leakage results show that when the stability test duration is 8 h，the capacity of designed vessels match the demand．Based on the results of mechanical analysis and theoretical calculation of heat leakage，it is known that the designed thermal meter meet the requirements for testing the multi-layer insulation performance．