These Sumitomo RDK-408D2 systems provide 1.0 W of cooling at a temperature of 4.2 K at the second stage and can reach a minimum temperature of 3 K (with no parasitic or experimental heat loads). Compact water- or air-cooled compressors and 6 m long flexible gas lines complete the refrigerator package. (Please see our compressors page for more information.) Designs incorporating both refrigerator and cryostat are available for a variety of applications.

Standard configuration


  • Refrigeration capacity 1 W at 4.2 K
  • Orientation independent
  • Push-button operation

Download the RDK-408D2 drawing and typical load map (252 KB).

Cold Head Model RDK-408D2 Specifications

Refrigeration cycleModified Gifford-McMahon
Refrigeration capacity
(Vertical Position)
50/60 Hz1st stage: 40/50 W at 43 K; 2nd stage: 1.0 W at 4.2 K
OrientationAny — capacity loss: maximum 15%
WeightApproximately 18 kg
Dimension180 W × 294 L × 557 H (mm)
Maintenance interval10,000 h
Flexline length6 m
Flexline weight5 kg per line
Compatible compressor unit modelCSA-71A, F-70L, F-70H

Specifications subject to change without notice.