Sunpower Pulse Tube cryocoolers, generally custom engineered for specific applications, are based on the same free-piston linear design qualified in other Sunpower products.  The Pulse Tube array includes single stage, two stage and coaxial configurations.

 

Sunpower published Status of Pulse Tube cryocooler Development at 2004 International Cryocooler Conference.

 

 

Configuration	Single Stage	Two-Stage		Coaxial
Status	Prototype	Prototype		Pre-production
Ambient Operation	-40°C to 60°C	-40°C to 60°C		-40°C to 60°C
Best Performance Orientation	Cold-end down	Cold-end down		Any
Nominal Cooler Input Power	100 Watts	100 Watts		100 Watts
Nominal Performance	6 Watts lift at 77K at 20°C reject	1st stage: No active load at ~80K at 20°C reject	2nd stage: 0.26 Watts lift at 30K	2 Watts lift at 60K at 37°C reject
No Load Temperature	40K	24.4K (19.8K at 300 Watts)		44K (40K at 140 Watts)