The Basic Insulation Characteristics of Solid-Nitrogen for Cryocooling of HTS Systems

고온초전도 시스템 냉각용 고화질소의 기초 절연 특성

  • 최재형 (경상대학교 전기공학과 및 공학연구원) ;
  • 최진욱 (경상대학교 전기공학과 및 공학연구원) ;
  • 이해근 (고려대학교 신소재공학부) ;
  • 송정빈 (고려대학교 신소재공학부) ;
  • 김해종 (한국전기연구원 초전도연구센터) ;
  • 성기철 (한국전기연구원 초전도연구센터) ;
  • 김상현 (경상대학교 전기공학과 및 공학연구원)
  • Published : 2009.01.01

Abstract

Recently, for improvement of the magnetic field of high temperature superconductor (HTS) apparatus, many studies investigating on operating in the range of $20{\sim}65\;K$ with liquid helium or the conducting method using cryocooler are actively reviewed. Also, the cooling method using solid nitrogen as cryogen is being suggested. Since the nitrogen has very large specific heat in solid state, it is expected that it can be operated for a long time without a continuous supply of cooling energy. However, there are still insufficient data on the characteristics of solid nitrogen such as thermodynamic properties and liquid-solid phase change. Especially, there was almost no study done on the electrical insulation properties of solid nitrogen so far. In this study, solid nitrogen to find the electrical characteristics was made by using cryocooler and cryostat, and investigated the flashover discharge and breakdown. The results of this study will be useful as a basic data for electrical insulation design of the HTS system using solid nitrogen as cryogen.

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