Studies of Cold Protection Diodes

  • Ruben Carcagno
  • John Zeigler


The feasibility of a passive quench protection system for the Superconducting Supercollider (SSC) main ring magnets depends on the radiation resistance and reliability of the diodes used as current bypass elements. These diodes would be located inside the magnet cryostat, subjecting them to liquid helium temperature and a relatively high radiation flux. Experimental and theoretical efforts have identified a commercially available diode which appears to be capable of surviving the cryogenic temperature and radiation environment of the accelerator. High current IV measurements indicate that the usable lifetime of this diode, based on an estimate of the peak junction temperature during a quench pulse, is an order of magnitude greater then than the expected lifetime of the SSC itself. However, an unexpected relationship was discovered between the diode turn-on voltage at 5 K and the most recent reverse voltage or temperature excursion. This turn-on voltage as a function of radiation exposure appears to be erratic and indicates a need for further investigation.


Carrier Lifetime Cryogenic Temperature Liquid Helium Temperature Junction Temperature Reverse Voltage 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Conceptual Design of the Superconducting Super Collider,“ SSC-SR-2020, March 1986, SSC Central Design Group, Lawrence Berkeley Laboratory, Berkeley, CA.Google Scholar
  2. 2.
    K. Robbins, W. Sampson, and M. Thomas, “Superconducting Magnet Quench Protection for ISABELLE,” IEEE Transactions on Nuclear Science, Vol. NS-24, No. 3, June 1977.Google Scholar
  3. 3.
    K. H. Mess, “Quench Protection at HERA,” Proceedings of the 1987 IEEE Particle Accelerator Conference, March 1987, pp. 1474–1476.Google Scholar
  4. 4.
    SSC Site-Specific Conceptual Design,“ December 1989, SSC Laboratory.Google Scholar
  5. 5.
    J. Zeigler and R. Carcagno, “Feasibility of Passive Quench Protection in the SSC,” Proc. MIDCON/88 Technical Conference, Dallas, TX, Aug. 30-Sept. 1, 1988.Google Scholar
  6. 6.
    D. Groom, “Radiation in the SSC Main Ring Tunnel,” Appendix 21 from “Report of the Task Force on Radiation Effects at the SSC,” SSC-SR-1035 (1988).Google Scholar
  7. 7.
    A. Gosh, W. B. Sampson, G. Stenby, and A. J. Stevens, “Radiation Exposure of Bypass Diodes,” SSC Technical Note No. 10, February 1984, Brookhaven National Laboratory.Google Scholar
  8. 8.
    H. J. Stein, “Electrical Studies of Neutron-Irradiated n-type Si: Defect Structure and Annealing,” Physical Review, Vol. 163, No. 3, November 1967, pp. 801–808.CrossRefGoogle Scholar
  9. 9.
    J. Zeigler and R. Carcagno, “Lifetime of Passive Quench Protection Diodes in the SSC,” Proc. of the 1989 Particle Accelerator Conference, March 1989.Google Scholar
  10. 10.
    J. Zeigler, R. Carcagno, and M. Weichold, “Experimental Measurements of Radiation Damage to Power Diodes at Cryogenic Temperatures,” Proc. of the 1987 Particle Accelerator Conference, March 1987.Google Scholar
  11. 11.
    G. Schlapper and J. Krohn, “Use of the Nuclear Science Center Reactor for Diode Response Testing,” Workshop on Quench Protection Diodes, Texas Accelerator Center, The Woodlands, TX, July 14–15, 1986.Google Scholar
  12. 12.
    J. Zeigler, R. Carcagno, M. Weichold, and G. Welch, “Results of Neutron Irradiation of Power Diodes at 80 K,” Technical Note TC1799, July 1987, Texas Accelerator Center.Google Scholar
  13. 13.
    R. Carcagno, “A Heat Sink Thermal Design for the SSC Passive Quench Protection Diodes,” SSC-N-432, SSC Central Design Group, Lawrence Berkeley Laboratory, Berkeley, CA, December 1987.Google Scholar
  14. 14.
    K. Mess et al., “The Quench Protection Diodes for Superconducting Magnets for HERA,” Proc. Thirteenth International Cryogenic Engineering Conference, Beijing, China, 1990 (to appear).Google Scholar

Copyright information

© Springer Science+Business Media New York 1990

Authors and Affiliations

  • Ruben Carcagno
    • 1
  • John Zeigler
    • 2
  1. 1.Superconducting Super Collider LaboratoryDallasUSA
  2. 2.Texas Accelerator CenterThe WoodlandsUSA

Personalised recommendations