Vacuum systems for cold atom sensors on microgravity platforms

Abstract

Cooling atoms to Nano-Kelvin requires an ultra-high vacuum system with complex features, such as coated optical accesses, paramagnetic materials, or differential pumping stages. Furthermore, the sensitivity of atom interferometers, one promising application of ultra-cold atoms, scales with the free evolution time (T) of the cold ensembles. In order to increase T, microgravity becomes necessary. Hence, the development of reliable, miniaturized UHV systems with the capability to withstand the rough environment of microgravity platforms is a key task to pave the way for high performance cold atom instruments. In order to minimize such complex vacuum systems various tests have to be performed. For instance the measurement of outgassing rates for critical components inside the chamber and leakage rates of metal sealed windows allow a more detailed dimensioning of the vacuum pumps. In addition to the challenge of miniaturization, most of the microgravity platforms are linked to a rough thermal and mechanical environment. Vacuum pumps and seals are supposed to endure vibrations and loads of rocket launches or drop tower impacts. In the case of the sounding rocket mission MAIUS, the motors induced loads to the payload of up to 13 g. This talk presents the challenges for vacuum systems on microgravity platforms. Test beds for outgassing rate measurement, window sealing technologies and loaded CF flanges are shown and first results for the tests are given