In order to verify the feasibility of applying high-Jc Nb_(3)Sn strand in fusion magnet,a full-size cable-in-conduit conductor(CICC)with short twist pitch(STP)cable pattern was manufactured and tested in SULTAN facili...In order to verify the feasibility of applying high-Jc Nb_(3)Sn strand in fusion magnet,a full-size cable-in-conduit conductor(CICC)with short twist pitch(STP)cable pattern was manufactured and tested in SULTAN facility at SPC,Switzerland.Three levels of cyclic electromagnetic(EM)load were applied on the sample stepwise,no visible decrease of current sharing temperature(TcsT was observed until the EM load increased to 80 kA×10.8 T,after that the Tcs decreased dramatically with the EM cycles,which suggested that irreversible deformation,causing a change in the strain state,or even damage has occurred in the superconducting strands.For investigating the reason which caused the conductor performance degradation,the tested conductor was dissected for metallographic observation.Eight segments which subjected to different EM loads were extracted from one of the legs,the geometric feature changes of the cable cross-sections were analyzed and compared.A good correlation was found between the decrease of the Tcs and deformation of the cable cross section.A mass of cracks were found on the sub-elements of strands in the segment which subjected to highest EM load,but the amount of crack is much lower in other segments.Combining the analyses,it is speculated that the critical EM load which causes irreversible degradation is between 850 kN/m and 870 kN/m for this conductor.The results could be a reference in high-Jc Nb_(3)Sn CICC design.展开更多
Cable-in-conduit conductor （CICC） conductor sample of the PF2 coil for ITER was tested in the SULTAN facility. According to the test results, the CICC conductor sample exhibited a stable performance regarding the cu...Cable-in-conduit conductor （CICC） conductor sample of the PF2 coil for ITER was tested in the SULTAN facility. According to the test results, the CICC conductor sample exhibited a stable performance regarding the current sharing temperature. Under the typical operational conditions of a current of 45 kA, a magnetic field of 4 T and a temperature of 5 K for PF2, the test result for the conductor current sharing temperature is 6.71 K, with a temperature margin of 1.71 K. For a comparison thermal-hydraulic analysis of the PF2 conductor was carried out using GANDALF code in a 1-D model, and the result is consistent with the test one.展开更多
The CICC (cable-in-conduit conductor) in ITER (International Thermal-nuclear Experimental Reactor) will run in high-current, fast transient magnet field and complex environment. In response to the impact of magnet fie...The CICC (cable-in-conduit conductor) in ITER (International Thermal-nuclear Experimental Reactor) will run in high-current, fast transient magnet field and complex environment. In response to the impact of magnet fields above 10 T, the Nb3Sn conductor has been introduced. However, the AC (alternating current) loss mechanism of Nb3Sn conductor on strain has not been explored. So, it is necessary to study the AC loss calculation method with transient electromagnetic field and wide range of strain, the coupling current in complex field and current signal of field is simplified to the spectrum effects of coil excitation, and calculation technology of AC loss, which contains the frequency, magnet field, coil characteristics and other parameters, is constructed to meet the discrete Fourier transform (DFT). By comparative analysis of simulation, it is found that the AC loss calculation of the conductor with spectrum algorithm is closer to the actual project value than the traditional algorithm. For the rapid excitation, in particular plasma discharge and burst, spectrum algorithm and the traditional algorithm are consistent. For the relative error calculation of hysteresis loss and coupling loss, it is found that the coupling loss is cumulative linearly, where the hysteresis loss is not so. As a function of the amplitude, frequency and phase angle, the relative error is less than 40%. The results showed that the method of Fourier restructuring is satisfactory.展开更多
The force flow cooled superconducting cable-in-conduit conductor （CICC） is used in both of EAST toroidal field （TF） and poloidal field （PF） coils. The conductor consists of multi-stage NbTi superconducting cable...The force flow cooled superconducting cable-in-conduit conductor （CICC） is used in both of EAST toroidal field （TF） and poloidal field （PF） coils. The conductor consists of multi-stage NbTi superconducting cable and 1.5 mm thick square jacket. The cable is pulled through in a thin wall circular jacket and then compacted to square cross-section conductor. The jacket material is SUS316LN austenitic stainless steel seamless tubes （about 10 m each）, which is assembled by butt-welding up to 600 m. The results of the welding procedure investigation and quality assurance procedures carrying out are described in this paper.展开更多
The conductors of both the toroidal field （TF） and poloidal field （PF） coils of EAST are NiTi cable-in-conduit conductors （CICCs）. The sizes of this type of CICC are 20.3 mm×20.3 mm and 18.5 mm×18.5 mm...The conductors of both the toroidal field （TF） and poloidal field （PF） coils of EAST are NiTi cable-in-conduit conductors （CICCs）. The sizes of this type of CICC are 20.3 mm×20.3 mm and 18.5 mm×18.5 mm respectively. A relevant R＆D program has been carried out for three years at the Research and Manufacture Center （RMC） of the Institute of Plasma Physics, Chinese Academy of Sciences （ASIPP） to acquire the manufacturing techniques and master the behavior of the testing joints. Based on the experience gained from the manufacture and test of a sub-cable joint, three kinds of joints were made. The final design was determined after carefully evaluating their simple mechanism, good cooling line, lower AC loss and resistance, compact size, and convenience for manufacture and on-site assembly. Two steps were developed to carry out the final joint. The first step was forming the terminals＇ super conductors. The second step was clamping the two terminals together to ensure their good contact with the copper conductor sole. The two terminals could be connected in different directions to get two kinds of conductor connections. A hydraulic instrument was developed to impact the terminals. It could impact the terminals in high accuracy in terms of their size and shape. The cross section of the terminal was tried in circular and an elliptic shape. Five full-size joints were made according to the design and then tested. When they were tested in bathing cold condition, their resistance was from 2 nΩ to 4 nΩ The latest joint was tested in real working conditions where the resistance varied from 2 nΩ to 12 nΩ, depending on the testing current ranging from 2 kA to 10 kA.展开更多
The superconducting joint of the NbTi Cable-in -conduit Conductor (CICC) has been developed and tested on the magnet test facility at Institute of Plasma Physics, Chinese Academy of Sciences. The CICC is composed of (...The superconducting joint of the NbTi Cable-in -conduit Conductor (CICC) has been developed and tested on the magnet test facility at Institute of Plasma Physics, Chinese Academy of Sciences. The CICC is composed of (2NbTi+lCu)x3x3x(6+ltube) strands each with 0.85 mm in diameter, which has been developed for a central solenoid model coil. The effective length of the joint is about 500 mm. There have been two common fabrication modes, one of them is to integrate the 2 CICC terminals with the copper substrate via lead-soldering, and the other is to mechanically compress the above two parts into an integrated unit. In the current range from 2 kA to 10 kA the joint resistance changes slightly. Up to now, 11 TF magnets, a central solenoid model coil, a central solenoid prototype coil, and a large PF model coil of PF large coil have been completed via the latter joint in the test facility.展开更多
Conductor qualification will be carried out with four Cable-in-Conduit Conductor （CICC） samples made of superconducting strands. The direct current （DC） performance of these samples will be tested in the SULTAN fa...Conductor qualification will be carried out with four Cable-in-Conduit Conductor （CICC） samples made of superconducting strands. The direct current （DC） performance of these samples will be tested in the SULTAN facility. The critical current densities of the strands can be well simulated by empirical equations. In this paper, a model is illustrated to predict the DC behaviour of the cable in light of the single strand＇s experimental properties. The simulation results were compared with experimental results.展开更多
A cable-in-conduit conductor(CICC ) production line was designed and constructed in Institute of Plasma Physics of Chinese Academy of Sciences (IPPCAS) by the end of 2000. It can produce a length of 600 meters and thr...A cable-in-conduit conductor(CICC ) production line was designed and constructed in Institute of Plasma Physics of Chinese Academy of Sciences (IPPCAS) by the end of 2000. It can produce a length of 600 meters and three kinds of sections of 20.8±0. 1×20.8±0.1, 20.4±0. 1×20.4± 0.1 and 18.6±0.1×18.6±0.1mm2. If the rollers of the shaping machine are changed, it can also produce other sizes of CICCs. So-called inserting-cable technology is adopted in this production line, where the procedures consist of tube pre-treatment (cleaning, pressure and leakage testing, end cutting), conduits butt-welding, six kinds of quality checking (endoscopy, dye penetration, pressure control, leakage testing, ultrasonic inspection and X-ray testing), cable inserting, shaping (compacting & squaring), pre-bending & winding and final checking. Now all the instruments and facilities required for these technologies have been installed and got ready. Some key technologies have been explored and good results obtained. Some short samples were produced and a 600 meters long sample was made out in August, 2001.展开更多
Superconducting TF and PF coils have been measured in SULTAN test facility. Segregated copper strands are included in four NbTi CICC and this is a technical innovation. Two AC losses measurement methods, calorimetric ...Superconducting TF and PF coils have been measured in SULTAN test facility. Segregated copper strands are included in four NbTi CICC and this is a technical innovation. Two AC losses measurement methods, calorimetric and electromagnetic methods, have been used in the experiments, and a broad frequency range (from 0.05 Hz to 6 Hz) is covered in sample test. The purpose of this experiment was to investigate AC losses of TF and PF CICC conductor including segregated copper and to check the design of PF and TF CICC coated with different resistive barriers (Pb-30Sn-2Sb and Ni plating on NbTi strands).展开更多
Under the condition of steady state, the pressure drop of coolant is mainly caused by friction along the cable. In the CICC (cable-in-conduit-conductor), helium flow within the conductor consists of two parallel inter...Under the condition of steady state, the pressure drop of coolant is mainly caused by friction along the cable. In the CICC (cable-in-conduit-conductor), helium flow within the conductor consists of two parallel interconnected tubes. The velocity distribution has some differece between the central channel and conductor space. The region of Reynolds number is from 103 to 106. This paper describes the calculation of pressure drop of HT-7U CICC at various mass flows. It is assumed that the coolant flows in two parallel, rough tubes during the calculation.展开更多
基金supported by the National Key R&D Program of China(Grant No.2017YFE0301404)the Comprehensive Research Facility for Fusion Technology Program of China under Contract No.2018-000052-73-01-001228。
文摘In order to verify the feasibility of applying high-Jc Nb_(3)Sn strand in fusion magnet,a full-size cable-in-conduit conductor(CICC)with short twist pitch(STP)cable pattern was manufactured and tested in SULTAN facility at SPC,Switzerland.Three levels of cyclic electromagnetic(EM)load were applied on the sample stepwise,no visible decrease of current sharing temperature(TcsT was observed until the EM load increased to 80 kA×10.8 T,after that the Tcs decreased dramatically with the EM cycles,which suggested that irreversible deformation,causing a change in the strain state,or even damage has occurred in the superconducting strands.For investigating the reason which caused the conductor performance degradation,the tested conductor was dissected for metallographic observation.Eight segments which subjected to different EM loads were extracted from one of the legs,the geometric feature changes of the cable cross-sections were analyzed and compared.A good correlation was found between the decrease of the Tcs and deformation of the cable cross section.A mass of cracks were found on the sub-elements of strands in the segment which subjected to highest EM load,but the amount of crack is much lower in other segments.Combining the analyses,it is speculated that the critical EM load which causes irreversible degradation is between 850 kN/m and 870 kN/m for this conductor.The results could be a reference in high-Jc Nb_(3)Sn CICC design.
基金supported by the Priority Base Research Development Project of China (No. 0559730532)
文摘Cable-in-conduit conductor （CICC） conductor sample of the PF2 coil for ITER was tested in the SULTAN facility. According to the test results, the CICC conductor sample exhibited a stable performance regarding the current sharing temperature. Under the typical operational conditions of a current of 45 kA, a magnetic field of 4 T and a temperature of 5 K for PF2, the test result for the conductor current sharing temperature is 6.71 K, with a temperature margin of 1.71 K. For a comparison thermal-hydraulic analysis of the PF2 conductor was carried out using GANDALF code in a 1-D model, and the result is consistent with the test one.
基金supported by the Major International (Regional) Joint Research Program of China (Grant No. 2004CB720704) the Excellent Young Teachers Program for Higher Education of Henan Province (Grant No. 2010GGJS-088)
文摘The CICC (cable-in-conduit conductor) in ITER (International Thermal-nuclear Experimental Reactor) will run in high-current, fast transient magnet field and complex environment. In response to the impact of magnet fields above 10 T, the Nb3Sn conductor has been introduced. However, the AC (alternating current) loss mechanism of Nb3Sn conductor on strain has not been explored. So, it is necessary to study the AC loss calculation method with transient electromagnetic field and wide range of strain, the coupling current in complex field and current signal of field is simplified to the spectrum effects of coil excitation, and calculation technology of AC loss, which contains the frequency, magnet field, coil characteristics and other parameters, is constructed to meet the discrete Fourier transform (DFT). By comparative analysis of simulation, it is found that the AC loss calculation of the conductor with spectrum algorithm is closer to the actual project value than the traditional algorithm. For the rapid excitation, in particular plasma discharge and burst, spectrum algorithm and the traditional algorithm are consistent. For the relative error calculation of hysteresis loss and coupling loss, it is found that the coupling loss is cumulative linearly, where the hysteresis loss is not so. As a function of the amplitude, frequency and phase angle, the relative error is less than 40%. The results showed that the method of Fourier restructuring is satisfactory.
基金The project supported by the National Meg-Science Engineering Project of the Chinese Government
文摘The force flow cooled superconducting cable-in-conduit conductor （CICC） is used in both of EAST toroidal field （TF） and poloidal field （PF） coils. The conductor consists of multi-stage NbTi superconducting cable and 1.5 mm thick square jacket. The cable is pulled through in a thin wall circular jacket and then compacted to square cross-section conductor. The jacket material is SUS316LN austenitic stainless steel seamless tubes （about 10 m each）, which is assembled by butt-welding up to 600 m. The results of the welding procedure investigation and quality assurance procedures carrying out are described in this paper.
基金supported by the National Meg-science Engineering Project of the Chinese Government
文摘The conductors of both the toroidal field （TF） and poloidal field （PF） coils of EAST are NiTi cable-in-conduit conductors （CICCs）. The sizes of this type of CICC are 20.3 mm×20.3 mm and 18.5 mm×18.5 mm respectively. A relevant R＆D program has been carried out for three years at the Research and Manufacture Center （RMC） of the Institute of Plasma Physics, Chinese Academy of Sciences （ASIPP） to acquire the manufacturing techniques and master the behavior of the testing joints. Based on the experience gained from the manufacture and test of a sub-cable joint, three kinds of joints were made. The final design was determined after carefully evaluating their simple mechanism, good cooling line, lower AC loss and resistance, compact size, and convenience for manufacture and on-site assembly. Two steps were developed to carry out the final joint. The first step was forming the terminals＇ super conductors. The second step was clamping the two terminals together to ensure their good contact with the copper conductor sole. The two terminals could be connected in different directions to get two kinds of conductor connections. A hydraulic instrument was developed to impact the terminals. It could impact the terminals in high accuracy in terms of their size and shape. The cross section of the terminal was tried in circular and an elliptic shape. Five full-size joints were made according to the design and then tested. When they were tested in bathing cold condition, their resistance was from 2 nΩ to 4 nΩ The latest joint was tested in real working conditions where the resistance varied from 2 nΩ to 12 nΩ, depending on the testing current ranging from 2 kA to 10 kA.
文摘The superconducting joint of the NbTi Cable-in -conduit Conductor (CICC) has been developed and tested on the magnet test facility at Institute of Plasma Physics, Chinese Academy of Sciences. The CICC is composed of (2NbTi+lCu)x3x3x(6+ltube) strands each with 0.85 mm in diameter, which has been developed for a central solenoid model coil. The effective length of the joint is about 500 mm. There have been two common fabrication modes, one of them is to integrate the 2 CICC terminals with the copper substrate via lead-soldering, and the other is to mechanically compress the above two parts into an integrated unit. In the current range from 2 kA to 10 kA the joint resistance changes slightly. Up to now, 11 TF magnets, a central solenoid model coil, a central solenoid prototype coil, and a large PF model coil of PF large coil have been completed via the latter joint in the test facility.
基金supported by the National Basic Research Program of China (No.151J00035602)
文摘Conductor qualification will be carried out with four Cable-in-Conduit Conductor （CICC） samples made of superconducting strands. The direct current （DC） performance of these samples will be tested in the SULTAN facility. The critical current densities of the strands can be well simulated by empirical equations. In this paper, a model is illustrated to predict the DC behaviour of the cable in light of the single strand＇s experimental properties. The simulation results were compared with experimental results.
文摘A cable-in-conduit conductor(CICC ) production line was designed and constructed in Institute of Plasma Physics of Chinese Academy of Sciences (IPPCAS) by the end of 2000. It can produce a length of 600 meters and three kinds of sections of 20.8±0. 1×20.8±0.1, 20.4±0. 1×20.4± 0.1 and 18.6±0.1×18.6±0.1mm2. If the rollers of the shaping machine are changed, it can also produce other sizes of CICCs. So-called inserting-cable technology is adopted in this production line, where the procedures consist of tube pre-treatment (cleaning, pressure and leakage testing, end cutting), conduits butt-welding, six kinds of quality checking (endoscopy, dye penetration, pressure control, leakage testing, ultrasonic inspection and X-ray testing), cable inserting, shaping (compacting & squaring), pre-bending & winding and final checking. Now all the instruments and facilities required for these technologies have been installed and got ready. Some key technologies have been explored and good results obtained. Some short samples were produced and a 600 meters long sample was made out in August, 2001.
文摘Superconducting TF and PF coils have been measured in SULTAN test facility. Segregated copper strands are included in four NbTi CICC and this is a technical innovation. Two AC losses measurement methods, calorimetric and electromagnetic methods, have been used in the experiments, and a broad frequency range (from 0.05 Hz to 6 Hz) is covered in sample test. The purpose of this experiment was to investigate AC losses of TF and PF CICC conductor including segregated copper and to check the design of PF and TF CICC coated with different resistive barriers (Pb-30Sn-2Sb and Ni plating on NbTi strands).
基金This work was supported by the National Meg-science Engineering Project of the Chinese Government.
文摘Under the condition of steady state, the pressure drop of coolant is mainly caused by friction along the cable. In the CICC (cable-in-conduit-conductor), helium flow within the conductor consists of two parallel interconnected tubes. The velocity distribution has some differece between the central channel and conductor space. The region of Reynolds number is from 103 to 106. This paper describes the calculation of pressure drop of HT-7U CICC at various mass flows. It is assumed that the coolant flows in two parallel, rough tubes during the calculation.
