Development of a load frame for neutron diffraction and fluorescent thermometry at cryogenic temperature.

Abstract

Over the years, rapidly rising interest in the mechanical properties of various materials at low temperatures has been simulated because of the growing cryogenic applications in modern engineering fields of space technology, environmental engineering, and superconductivity engineering. Realizing in situ measurement of the internal strain and the full-field strain and the temperature distribution of related materials in a cryogenic loading environment is a significant requirement for safety assessment and related research of some new large science facility projects. Here, we present a novel cryogenic load frame, which is suitable for neutron scattering measurements of internal stress at the temperature range of 6-300K. The loading capacity is 2500 N, and the slowest loading speed is 0.001 mm/s. By replacing the vacuum chamber sealing plate with a K9 glass window, the in situ digital image correlation strain measurement can be realized. Furthermore, fluorescence thermometry has also been investigated during a heating and cooling process without deformation. Using the present design, some typical results of the 316LN stainless steel and the YBCO tape at low temperatures were introduced.