6 W Full-Flexure-Bearing Stirling Cryocooler for the Cryosystem Program

• Published in: Advances in Cryogenic Engineering; Volume 49B Vol. 710; pp. 1420 - 1427
• Main Authors: Benschop, A A J, Bruins, P C, Mullie, J C, Meijers, M, Helmonds, H, Trollier, T
• Format: Journal Article
• Language: English
• Published: 23.06.2004
• ISBN: 9780735403840; 0735403848
• ISSN: 0094-243X
• DOI: 10.1063/1.1774834

In February 2002, ASTRIUM selected AL/DTA for the delivery of the vial freezers for the ESA / CRYOSYSTEM project. The CRYOSYSTEM is a set of facilities for ultra-rapid cooling, preservation and storage of biological samples and protein crystals at -180 deg C on-board the ISS.While selecting the cooler for this program, AL/DTA recognised that THALES' moving magnet flexure-bearing coolers offer the reliability required for space programs, for a price that is far below what is usual for space cryocoolers.Based on the cold finger of the existing LSF9320 cryocooler (5.6 W at 80 K for 150 W input), THALES has developed a cold finger with flexure-bearing support of the displacer. Combined with the moving magnet flexure-bearing compressor, this offers a very long lifetime and a very high reliability.The paper describes the development of the flexure-bearing supported displacer, which has an extra driving rod to increase its efficiency compared with conventional free displacer fingers. The efficiency optimisation and mass reduction has led to a cooler with a total mass (including heat-sinking and EMI shield) of 7.8 kg, with a cooling power of 6.6 W at 75 K for 100 W input. The results of the ongoing space qualification program will be discussed.