“Thermal contraction measurements down to 1.9 K and future developments at EN-MME Mechanical Measurement Lab”
Speakers: Oscar Sacristan De Frutos and Stefan Hoell/EN-MME-EDM
Abstract:
High-energy accelerators require numerous systems to be operated at cryogenic temperatures. Understanding the thermo-mechanical behavior of the constituent materials of such systems, is paramount for their performance and reliability. Due to the scarcity of commercial systems capable of measuring the thermal contraction down to 2 K, a customized dilatometric test bench has been developed through a collaboration between EN-MME Mechanical Measurement Laboratory and the external company attoCUBE.
During an initial extensive validation campaign, we focused on two main aspects: optimizing and determining the measurement accuracy and elaborating a suitable sample preparation to avoid limitations of the measurable materials caused by the requirements of the optical dilatometry. To quantify the accuracy of the device, we compared measurements on reference materials with highly accurate literature data. While we continued to improve the accuracy of the system, we completed a series of characterization campaigns on various materials, such as superconducting coils.
Taking advantage of the versatility of the system, we initiated the development of further testbenches with focus on a set-up to determine thermal conductivity of standard samples down to 2 K, which is nowadays in the prototyping phase. Following this, a second line of development will be devoted to the determination of specific heat. The completion of the previously mentioned developments will expand the thermal characterization capabilities of EN-MME Mechanical Measurement Laboratory from 2 K all the way up to 2000 °C.