Chaînes cryogéniques SPICA fonctionnant à des températures en dessous du Kelvin.
SPICA sub-Kelvin cryogenic chains.
Auteurs : DUBAND L., DUVAL J. M., LUCHIER N., et al.
Type d'article : Article
Résumé
SPICA, a Japanese led mission, is part of the JAXA future science program and is planned for launch in 2018. SPICA will perform imaging and spectroscopic observations in the mid- and far-IR waveband, and is developing instrumentation spanning the 5–400 lm range. The SPICA payload features several candidate instruments, some of them requiring temperature down to 50 mK. This is currently the case for SAFARI, a core instrument developed by a European-based consortium, and BLISS proposed by CALTECH/JPL in the US. SPICA’s distinctive feature is to actively cool its telescope to below 6 K. In addition, SPICA is a liquid cryogen free satellite and all the cooling will be provided by radiative cooling (L2 orbit) down to 30 K and by mechanical coolers for lower temperatures. The satellite will launch warm and slowly equilibrate to its operating temperatures once in orbit. This warm launch approach makes it possible to eliminate a large liquid cryogen tank and to use the mass saved to launch a large diameter telescope (3.2 m). This 4 K cooled telescope significantly reduces its own thermal radiation, offering superior sensitivity in the infrared region. The cryogenic system that enables this warm launch/cooled telescope concept is a key issue of the mission. This cryogenic chain features a number of cooling stages comprising passive radiators, Stirling coolers and several Joule Thomson loops, offering cooling powers at typically 20, 4.5, 2.5 and 1.7 K. The SAFARI and BLISS detectors require cooling to temperatures as low as 50 mK. The instrument coolers will be operated from these heat sinks. They are composed of a small demagnetization refrigerator (ADR) pre cooled by either a single or a double sorption cooler, respectively for SAFARI and BLISS. The BLISS cooler maintains continuous cooling at 300 mK and thus suppresses the thermal equilibrium time constant of the large focal plane. These hybrid architectures allow designing low weight coolers able to reach 50 mK. Because the sorption cooler has extremely low mass for a sub-Kelvin cooler, it allows the stringent mass budget to be met. These concepts are discussed in this paper. [Reprinted with permission from Elsevier. Copyright, 2012].
Détails
- Titre original : SPICA sub-Kelvin cryogenic chains.
- Identifiant de la fiche : 30003951
- Langues : Anglais
- Source : Cryogenics - vol. 52 - n. 4-6
- Date d'édition : 04/2012
- DOI : http://dx.doi.org/10.1016/j.cryogenics.2012.01.030
Liens
Voir d'autres articles du même numéro (13)
Voir la source
Indexation
-
Thèmes :
Cryogénie: sécurité, instrumentation et métrologie;
Supraconduction - Mots-clés : Japon; Télescope; Sorption; Espace; Désaimantation; Cryorefroidisseur; Cryogénie
-
Design of the PIXIE cryogenic system.
- Auteurs : DIPIRRO M., FIXSEN D., KOGUT A., et al.
- Date : 04/2012
- Langues : Anglais
- Source : Cryogenics - vol. 52 - n. 4-6
Voir la fiche
-
Design of the PIXIE adiabatic demagnetization r...
- Auteurs : SHIRRON P. J., KIMBALL M. O, FIXSEN D. J., et al.
- Date : 04/2012
- Langues : Anglais
- Source : Cryogenics - vol. 52 - n. 4-6
Voir la fiche
-
Cryopump systems and space telescopes.
- Auteurs : DAVE H.
- Date : 2013
- Langues : Anglais
- Source : Cold Facts - vol. 29 - n. 3
Voir la fiche
-
Cryogenic aspects of ISOPHOT, the photometer fo...
- Auteurs : LEMKE D., LUTZOW-WENTZKY P., FRICKE W., BOLLINGER W.
- Date : 04/1993
- Langues : Anglais
- Source : Cryogenics - vol. 33 - n. 4
Voir la fiche
-
Design and predicted performance of the 3-stage...
- Auteurs : SHIRRON P. J., KIMBALL M. O, JAMES B. L., et al.
- Date : 04/2012
- Langues : Anglais
- Source : Cryogenics - vol. 52 - n. 4-6
Voir la fiche