Progress in Superconductivity and Cryogenics (한국초전도ㆍ저온공학회논문지)

The Korean Society of Superconductivity and Cryogenics (한국초전도저온학회)
권호 표지
DOI QR코드

DOI QR Code

Commissioning result of the KSTAR in-vessel cryo-pump

  • Chang, Y.B. (National Fusion Research Institute) ;
  • Lee, H.J. (National Fusion Research Institute) ;
  • Park, Y.M. (National Fusion Research Institute) ;
  • Lee, Y.J. (National Fusion Research Institute) ;
  • Kwag, S.W. (National Fusion Research Institute) ;
  • Song, N.H. (National Fusion Research Institute) ;
  • Park, D.S. (National Fusion Research Institute) ;
  • Joo, J.J. (National Fusion Research Institute) ;
  • Moon, K.M. (National Fusion Research Institute) ;
  • Kim, N.W. (National Fusion Research Institute) ;
  • Yang, H.L. (National Fusion Research Institute) ;
  • Oh, Y.K. (National Fusion Research Institute)
  • Published : 2013.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

KSTAR in-vessel cryo-pump has been installed in the vacuum vessel top and bottom side with up-down symmetry for the better plasma density control in the D-shape H-mode. The cryogenic helium lines of the in-vessel cryo-pump are located at the vertical positions from the vacuum vessel torus center 2,000 mm. The inductive electrical potential has been optimized to reduce risk of electrical breakdown during plasma disruption. In-vessel cryo-pump consists of three parts of coaxial circular shape components; cryo-panel, thermal shield and particle shield. The cryo-panel is cooled down to below 4.5 K. The cryo-panel and thermal shields were made by Inconel 625 tube for higher mechanical strength. The thermal shields and their cooling tubes were annealed in air environment to improve the thermal radiation emissivity on the surface. Surface of cryo-panel was electro-polished to minimize the thermal radiation heat load. The in-vessel cryo-pump was pre-assembled on a test bed in 180 degree segment base. The leak test was carried out after the thermal shock between room temperature to $LN_2$ one before installing them into vacuum vessel. Two segments were welded together in the vacuum vessel and final leak test was performed after the thermal shock. Commissioning of the in-vessel cryo-pump was carried out using a temporary liquid helium supply system.

Keywords

References

  1. J. P. Smith, C. B. Baxi, et al., "The design and fabrication of a toroidally continuous cryocondensation pump for the DIII-D advanced divertor", J. Fusion Engineering vol 2. 1230 (1991)
  2. J. P. Smith, et al., "Installation and Initial Operation of the DIII-D Advances Divertor Cryocondensation Pump," proc. 15th Symp. On Fusion Engineering, Hyannis, 1993.
  3. G. L. LAUGHON, et al., "Two Phase Liquid Helium Flow Testing to Simulate Operation of Cryocondensation Pump in the DIII-D Tokamak," presented at the 15th International Cryogenic Engineering Conf. Industrial Exhibition, Genoa, Italy, June 7-10, 1994.
  4. J. P. Smith, et al., "Engineering Design of a Radiative Divertor for DIII-D," proc. 16th Symp. On Fusion Engineering, Champaign, IIIinois, 1995, Vol. 1, 858 (1996)
  5. A. S. Bozek, C. B. Baxi, et al., "Engineering Design of Cryocondensation pumps for the DIII-D radiative divertor program", proc. 16th Symp. On Fusion Engineering, Champaign, IIIinois, 1995, Vol. 2, 898 (1996)
  6. E. E. Reis, C. B. Baxi, et al., "Design and analysis of the cryopump for the DIII-D upper divertor", proc. 18th Symp. On Fusion Engineering 519-522 (1999)
  7. P. S. Mauzey, K. L. Holtrop, P. M. Anderson, "Control Improvements for the DIII-D Cryo System", proc. 20th Symp. On Fusion Engineering 1-4 (2005)
  8. H. J. LEE, et al., "Engineering of the KSTAR In-vessel Cryo-pump," 2010 KSTAR Conference, Feb. 2010.
  9. H. J. LEE, et al., "Design and Fabrication of the KSTAR In-vessel Cyro-pump," Volume 86, Issues 9-11, October 2011, Pages 1993-1996
  10. S. W. KWAG, et al., "Commissioning result of the In-vessel cryopump for 4th campaign," 2010 KSTAR Conference, Feb. 2011.