It′s important that HTS tapes have lower thermal conductivity and higher transversal resistivity in order to reduce the heat leaks conducted along the tapes and AC losses in the high temperature superconducting syste...It′s important that HTS tapes have lower thermal conductivity and higher transversal resistivity in order to reduce the heat leaks conducted along the tapes and AC losses in the high temperature superconducting system conduction cooled by GM coolers. This paper presents an experimental investigation into the effects of pure Ag and AgAu alloys sheath materials on the properties of Bi(2223) multifilamentary tapes and the optimisation of conduction cooled hybrid current leads made from copper and Bi(2223)/Ag or Bi(2223)/AgAu tapes. The thermal conductivity of the tapes were measured by cryogenic steady heat flux method and the resistance was measured by using standard DC four probe method at low temperature. The results showed that the reduction of thermal conductivity by the addition of Au into the sheath material of Bi(2223) tapes was 65 0 0, 75 0 0 and 85 0 0 lower than that of pure Ag sheathed Bi(2223) tapes and the increase of resistivity was 4.9 , 10 and 19.4 times higher than that of pure Ag for the addition of 2.2 0 0, 5.7 0 0 and 10.7 0 0Au(atom ratio) respectively. And the study also attempts to optimise thermodynamically the conduction cooled hybrid current lead by using a developed model, which took the irreversibility of commercial GM coolers, the contact resistance and thermal conductance into account. Predictions from the model showed that AgAu alloys were suitable candidate materials to replace Ag as sheath material of Bi(2223) tapes applied in HTS current leads. In addition, Bi(2223)/AgAu was a suitable material to be applied as the HTS section of hybrid current leads in conduction cooled superconducting electric systems.展开更多
In an ADS injector i, there are five superconducting magnets in each cryomodule. Each superconducting magnet contains a solenoid magnet, a horizontal dipole corrector （HDC）, and a vertical dipole corrector （VDC）. ...In an ADS injector i, there are five superconducting magnets in each cryomodule. Each superconducting magnet contains a solenoid magnet, a horizontal dipole corrector （HDC）, and a vertical dipole corrector （VDC）. Six current leads will tm required to power the electrical circuits, from room temperature to the 2.1 K liquid helium bath： two leads carry 100 A current for the solenoid magnet while the other four carry 12 A for the HDC and the VDC. This paper presents the principle of current lead optimization, which includes the cooling methods, the choice of material and structure, and the issues for current lead integration.展开更多
Purpose As the world energetic demand is increasing day by day,the development of nuclear energy is of great necessity.However,the development is followed by a lot of tough questions like the management and storage of...Purpose As the world energetic demand is increasing day by day,the development of nuclear energy is of great necessity.However,the development is followed by a lot of tough questions like the management and storage of the nuclear waste.ADS,which is short for the accelerator-driven sub-critical system,may be a good choice because it can provide an efficient transmutations of nuclear waste.Many countries have carried out some research in related areas like the USA,Japan and China.The superconducting magnet system The cryomodule I(CM1)for China’s ADS Injection-I had been designed,fabricated and online tested.The CM1 is mainly composed of superconducting spoke cavities,beam positionmonitors,cryogenic system and superconducting magnets.The superconducting magnet system,which includes the magnet and current leads,is aimed at focusing and correcting the proton beams.Conclusion Seven superconducting magnets and current leads for CM1 are successfully designed and manufactured.Structural strength meets design specifications,the field meets the design demands,and the online test shows that the magnets can work in a rather stable state.In this paper,the detailed design and installation of the superconducting magnets are presented.展开更多
文摘It′s important that HTS tapes have lower thermal conductivity and higher transversal resistivity in order to reduce the heat leaks conducted along the tapes and AC losses in the high temperature superconducting system conduction cooled by GM coolers. This paper presents an experimental investigation into the effects of pure Ag and AgAu alloys sheath materials on the properties of Bi(2223) multifilamentary tapes and the optimisation of conduction cooled hybrid current leads made from copper and Bi(2223)/Ag or Bi(2223)/AgAu tapes. The thermal conductivity of the tapes were measured by cryogenic steady heat flux method and the resistance was measured by using standard DC four probe method at low temperature. The results showed that the reduction of thermal conductivity by the addition of Au into the sheath material of Bi(2223) tapes was 65 0 0, 75 0 0 and 85 0 0 lower than that of pure Ag sheathed Bi(2223) tapes and the increase of resistivity was 4.9 , 10 and 19.4 times higher than that of pure Ag for the addition of 2.2 0 0, 5.7 0 0 and 10.7 0 0Au(atom ratio) respectively. And the study also attempts to optimise thermodynamically the conduction cooled hybrid current lead by using a developed model, which took the irreversibility of commercial GM coolers, the contact resistance and thermal conductance into account. Predictions from the model showed that AgAu alloys were suitable candidate materials to replace Ag as sheath material of Bi(2223) tapes applied in HTS current leads. In addition, Bi(2223)/AgAu was a suitable material to be applied as the HTS section of hybrid current leads in conduction cooled superconducting electric systems.
文摘In an ADS injector i, there are five superconducting magnets in each cryomodule. Each superconducting magnet contains a solenoid magnet, a horizontal dipole corrector （HDC）, and a vertical dipole corrector （VDC）. Six current leads will tm required to power the electrical circuits, from room temperature to the 2.1 K liquid helium bath： two leads carry 100 A current for the solenoid magnet while the other four carry 12 A for the HDC and the VDC. This paper presents the principle of current lead optimization, which includes the cooling methods, the choice of material and structure, and the issues for current lead integration.
文摘Purpose As the world energetic demand is increasing day by day,the development of nuclear energy is of great necessity.However,the development is followed by a lot of tough questions like the management and storage of the nuclear waste.ADS,which is short for the accelerator-driven sub-critical system,may be a good choice because it can provide an efficient transmutations of nuclear waste.Many countries have carried out some research in related areas like the USA,Japan and China.The superconducting magnet system The cryomodule I(CM1)for China’s ADS Injection-I had been designed,fabricated and online tested.The CM1 is mainly composed of superconducting spoke cavities,beam positionmonitors,cryogenic system and superconducting magnets.The superconducting magnet system,which includes the magnet and current leads,is aimed at focusing and correcting the proton beams.Conclusion Seven superconducting magnets and current leads for CM1 are successfully designed and manufactured.Structural strength meets design specifications,the field meets the design demands,and the online test shows that the magnets can work in a rather stable state.In this paper,the detailed design and installation of the superconducting magnets are presented.
