| PROPOSAL NUMBER: | 17.04-8670 (For NASA Use Only - Chron: 001331 ) |
| PROPOSAL TITLE: | Multi-Stage Pulse-Tube Cryocoolers for Sensor and Electronics Applications |
TECHNICAL ABSTRACT (LIMIT 200 WORDS)
Sunpower proposes to build and test a compact three-stage pulse tube cryocooler designed for simultaneous cooling loads on all three stages, with third-stage temperature in the range of 4-10 K. A linear compressor with less than 500 W electrical input will drive the cold head with frequency on the order of 30 Hz, charge pressure on the order of 20 bar and a pressure amplitude on the order of 15% of the charge pressure. Such a cryocooler will mark a significant advancement from low frequency high pressure-amplitude Gifford-McMahon technology, which is the only closed-cycle cryocooler technology available today in this temperature range.
It is likely that the cryocooler we develop would be directly useful to the NASA Goddard ADR (adiabatic demagetication refrigerator) project, as well as to other NASA missions requiring cooling in the range of 4-10 K.
The cryocooler also has potential applications in radio astronomy, such as 4K cooling for the Atacama Large Millimeter Array (ALMA) radio telescope.
This project will employ the Sage pulse-tube design software (Gedeon Associates) for the multi-stage cryocooler modeling as well as the overall cryo-package optimization.
POTENTIAL COMMERCIAL APPLICATIONS
We believe that at least two potentially large emerging commercial markets would be well served by the cryocooler we propose to develop. The first is the wireless (and optical) communications hardware infrastructure market, which requires cooling at 4.5 K for LTS (low temperature superconducting) digital circuits. The second is the MRI (magnetic-resonance imaging) medical-imaging market, which requires cooling at 4.2 K for superconducting magnets. These technologies currently employ niobium as the LTS material and work best at temperatures no higher than about 4.5 K. Future developments using other materials (notably magnesium diboride) promise operating temperatures approaching 20 K, where our cryocooler technology would operate much more efficiently.
There are also a limited number of commercial ADR systems used in laboratory industrial applications for such applications as cooling X-ray detectors.
In the temperature range of 10-15 K, there is the established vacuum cryopumping market. Today, Gifford-McMahon cooling technology has a firm grip on this market. But we feel our proposed cryocooler could eventually compete, on the basis of lower cost, smaller size, increased efficiency and equal, or better, reliability.
NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR
(Name, Organization Name, Mail Address, City/State/Zip)
Kyle Wilson
Sunpower, Inc.
182 Mill Street
Athens , OH 45701 - 2627
NAME AND ADDRESS OF OFFEROR
(Firm Name, Mail Address, City/State/Zip)
Sunpower, Inc.
182 Mill Street
Athens , OH 45701 - 2627