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Ravex, A.

Publications and source records attributed to Ravex, A..

Automatic sample Dewar for MX beam-line

It is very common for crystals of large biological macromolecules to show considerable variation in quality of their diffraction. In order to increase the number of samples that are tested for diffraction quality before any full data collections at the ESRF*, an automatic sample Dewar has been implemented. Conception and performances of the Dewar are reported in this paper. The automatic sample Dewar has 240 samples capability with automatic loading/unloading ports. The storing Dewar is capable to work with robots and it can be integrated in a full automatic MX** beam-line. The samples are positioned in the front of the loading/unloading ports with and automatic rotating plate. A view port has been implemented for data matrix camera reading on each sample loaded in the Dewar. At last, the Dewar is insulated with polyurethane foam that keeps the liquid nitrogen consumption below 1.6 L/h. At last, the static insulation also makes vacuum equipment and maintenance unnecessary. This Dewar will be useful for increasing the number of samples tested in synchrotrons.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Development of a vacuum compatible rotary dynamic seal for cryogenic liquids

Liquid nitrogen is commonly circulating through radiative panels which cover satellite supporting structure inside thermal vacuum test chamber. In the Large Space Simulator (LSS) located in the ESA* ESTEC** Test Centre, there is the need to move the satellite specimen inside the vacuum chamber to modify its relative orientation vis-à-vis the artificial sun beam. Re-orientation of the radiative panels is then required. ESA is currently developing a New Motion System (NMS) allowing dynamic motion from Gimbal to the Yoke Stand without any reconfiguration of the test. To do so, a nitrogen supply is required which can follow the rotation of the thermal shrouds under vacuum. Nitrogen flexible hoses are not anymore suitable due to their volume and mass constraints and due to the limitation in the rotation range. This paper describes the design, manufacturing and tests of a new compact multi-turn Rotary Nitrogen Joint (RNJ) compliant with thermal vacuum conditions used for spacecraft thermal testing. This prototype development is funded by the ESA Technology and Research Program. *European Space Agency **European Space Research and Technology Centre.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗