Influence of the astrophysical requirements on dilution refrigerator design

A 300 K to 0.1 K space prototype is developed in cooperation with CRTBT, IA S Air Liquide and RAL, under CNES and ESA contracts, to demonstrate the fea sibility of such a cooling system. The heart of the system is a 4 K to 0.1 K open cycle dilution refrigerator circulating He-3 and He-4. All the tests are now completed. The design of this system is chosen like the nominal so lution for PLANCK/HFI instrument, Since scientific requirements have change d, the design of the prototype has to be adjusted to receive the focal plan e of HFI (High Frequency Instrument) instrument of PLANCK. The main goal is to optimise 3He consumption without degrading both mechanical and thermal performances. This paper presents the prototype architecture, the dilution refrigerator a nd the associated tests. The suitability to PLANCK mission is also assessed . Published by Elsevier Science Ltd.