Advertisement

Performance and Control of a Cryogenic System Cooling 1152 VLPC Channels

  • T. H. Gasteyer
  • P. D. Wheelwright
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 43)

Abstract

A liquid helium supplied cryogenic system has been designed, built, and operated continuously since September 1996. The system cools nine cassettes (128 channels each) of visible light photon counter (VLPC) chips to 6.5 K. Thermal stability of the chips has been excellent. Liquid helium is supplied from a modified CTI 1400 helium liquifier. The liquid flows into a vacuum insulated liquid nitrogen shielded cryostat where it cools the VLPC chips. Some of the helium boil off is used to reduce the cryostat heat leak. All boil off gas is returned to the compressor suction header for the Tevatron. The exceptional control of the cassette temperatures is achieved with two levels of PID control. The coarse control (All cassettes within 0.5 K) is reached by maintaining constant cryostat liquid level, cryostat pressure, and heat intercept flow. The fine tuning (All cassettes within +/-0.010 K) is achieved with automatically controlled heaters in each cassette. The operating temperature range for the chips can be set anywhere between 5 to 15 K. The cryostat heat leak is about 2.0 W at 6.5 K.

Keywords

Liquid Helium Annular Flow Heat Leak Flow Control Valve Control System Performance 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    T. H. Gasteyer, K. J. Krempetz, A. Lee, R. A. Rucinski, and A. M. Stefanik, “Heat transfer design and performance of a helium cryostat operating at 6.5 K”, Advances in Cryogenic Engineering, Vol. 39A, P. 619, Plenum Press, New York, 1994CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • T. H. Gasteyer
    • 1
  • P. D. Wheelwright
    • 1
  1. 1.Fermi National Accelerator LaboratoryBataviaUSA

Personalised recommendations