Thermal Performance of the Cebaf Superconducting Linac Cryomodule

  • W. Schneider
  • W. Chronis
  • M. Drury
  • D. Machie
  • J. Marshall
  • J. Preble
  • J. Robb
  • C. Rode
  • Q. Saulter
  • M. Wiseman
Chapter
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 39)

Abstract

When complete, the Continuous Electron Beam Accelerator Facility (CEBAF) will be centered on a 4 GeV recirculating linac. Each of the two linacs contains 160 superconducting radio frequency (SRF) 1497 MHz niobium cavities1 in 20 cryomodules operating between 2 and 2.3 K. Minimization of the total heat load is critical to machine performance, since the refrigeration capacity is fixed. The total heat load of the cryomodule consists of the static load (fixed heat leak) and the dynamic load (proportional to the cavity performance Qo, or quality factor). The heat load of the cryomodules is the single largest load to both the primary and secondary cooling circuits of the refrigerator. The optimization of the thermal performance of the cryomodule considers recent test data of multilayer insulation (MLI) systems developed for the SSC, in addition to the effect of the dynamic heat load on the design of the cryostat. The design of the cryomodule and the measured thermal performance of the installed north and south linac cryomodules are discussed. The performance to date is shown to meet the design heat loads for the accelerator.

Keywords

Total Heat Helium Nylon Hydride Emissivity 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    P. Kneisel, et al., Performance of superconducting savities for CEBAF, “Conference Record of the 1991 IEEE Particle Accelerator Conference,” (San Francisco, 1991), Vol. 4.Google Scholar
  2. 2.
    H. A. Grunder, et al., The Continuous Electron Beam Accelerator Facility, in: “Proceedings of the 1987 IEEE Particle Accelerator Conference,” ed. E. R. Lindsrom and L. S. Taylor, (Washington, D.C., 1987), Vol. 1, pp. 13–18.Google Scholar
  3. 3.
    D. Kashy, et al., CEBAF transfer line system, in: “Proceedings of the 1991 Cryogenic Engineering Conference,” (Los Angeles, 1991), Vol 37, pp. 573–586.Google Scholar
  4. 4.
    D. Arenius, et al., “Commissioning and Operation of the CEBAF 2K Refrigeration System”, presented at the 1991 Cryogenic Engineering Conference. (Los Angeles, 1991) Vol. 37Google Scholar
  5. 5.
    C. Rode, and D. Proch, 2K CEBAF cryogenics, in: “Proceedings of the 1989 Cryogenic Conference,” (Los Angeles, 1989).Google Scholar
  6. 6.
    P. Kneisel, Test of superconducting accelerator structures in closed vacuum systems, in: “Proceedings of the 1987 IEEE Particle Accelerator Conference,” (Washington, D.C., 1987), Vol. 3, pp. 1893–95.Google Scholar
  7. 7.
    M. Dzenus, et al., Production of superconducting niobium cavities for CEBAF, in: “Proceedings of the 1991 IEEE Particle Accelerator Conference,” (San Francisco, 1991), Vol. 4, pp. 2390–92.CrossRefGoogle Scholar
  8. 8.
    H. F. Dylla, Operating experience with SRF cavities, in: “Proceedings of the 1993 Particle Accelerator Conference,” (Washington, D.C., 1993).Google Scholar
  9. 9.
    G. Biallas, et al., The CEBAF Superconducting Accelerator Cryomodule, IEEE Trans Mag., 23: 615 (1987).CrossRefGoogle Scholar
  10. 10.
    P. Brindza, et al., An optimized input waveguide for the CEBAF superconducting linac cavity, in: “Proceedings of the Applied Superconducting Conference,” (Baltimore, 1987).Google Scholar
  11. 11.
    J. P. Kelley, et al., Thermal design and evaluation of the CEBAF superconducting rf cavity waveguide, in: “Proceedings of the 1989 Cryogenic Engineering Conference,” (Los Angeles, 1989), Vol. 36.Google Scholar
  12. 12.
    J. D. Gonczy, et al., Thermal performance measurements of a 100 percent polyester MLI system for the Superconducting Super Collider part II laboratory results (300 K-80K), in: “Proceedings of the 1989 Cryogenic Engineering Conference,” (Los Angeles, 1989), Vol. 36.Google Scholar
  13. 13.
    R. P. Shutt, Private Communication (1978).Google Scholar
  14. 14.
    K. Saito, and P. Kneisel, Q Degradation in Superconducting Cavities, CEBAF Tech Note 91–033.Google Scholar
  15. 15.
    C. Reece, et al., Performance of production SRF cavities for CEBAF, in: “Proceedings of the 1993 Particle Accelerator Conference,” (Washington, D.C., 1993).Google Scholar
  16. 16.
    M. Drury, et al., Commissioning of the CEBAF cryomodules, in: “Proceedings of the 1993 Particle Accelerator Conference,” (Washington, D.C., 1993).Google Scholar

Copyright information

© Springer Science+Business Media New York 1994

Authors and Affiliations

  • W. Schneider
    • 1
  • W. Chronis
    • 1
  • M. Drury
    • 1
  • D. Machie
    • 1
  • J. Marshall
    • 1
  • J. Preble
    • 1
  • J. Robb
    • 1
  • C. Rode
    • 1
  • Q. Saulter
    • 1
  • M. Wiseman
    • 1
  1. 1.Continuous Electron Beam Accelerator FacilityNewport NewsUSA

Personalised recommendations