Leakage rate detection of ConFlat seals in aluminum and stainless steel flanges under mechanical loads for quantum optical experiments in space

Abstract

Several space missions, such as quantum optical experiments or quantum sensors, require ultrahigh vacuum (UHV) systems to perform their experiments and fulfill the scientific mission goals. Most of these experiments use standard ConFlat (CF) flanges for the design of the UHV system. One of the biggest challenges for these vacuum systems during a space mission is the mechanical loads. These loads are applied during launch, stage separation, etc., as a combination of static and dynamic loads. When loads are applied, the UHV system can experience an increased leakage rate, which decreases the vacuum quality. Investigation of the rise of the leakage rate due to static loads is an important step to allow a proper design process of space suitable UHV systems. In this paper, CF DN40 flange connections will be experimentally tested for standard aluminum (AluVaC) and stainless steel (316LN-ESR, 14429-ESU) tubes. Additionally, three different bolt pretension torques of 10, 12.5, and 15 N m are tested and compared. The presented results can be used to improve the design and assembly procedure for future UHV systems, such as the MAIUS (Matter-Wave Interferometry under Microgravity) sounding rocket missions.