The strain and temperature sensing performance of fiber-optic Bragg gratings （FBGs） with soft polymeric coating, which can be used to sense internal strain in superconducting coils, are evaluated under variable cryo...The strain and temperature sensing performance of fiber-optic Bragg gratings （FBGs） with soft polymeric coating, which can be used to sense internal strain in superconducting coils, are evaluated under variable cryogenic field and magnetic field. The response to a temperature and strain change of coated-soft polymeric FBGs is tested by comparing with those of coated-metal FBGs. The results indicate that the coated-soft polymeric FBGs can freely detect temperature and thermal strain, their At variable magnetic field, the tested results indicate accuracy and repeatability are also discussed in detail. that the cross-coupling effects of FBGs with different matrixes are not negligible to measure electromagnetic strain during fast excitation. The present results are expected to be able to provide basis measurements on the strain of pulsed superconducting magnet/cable （cable- around-conduit conductors, cable-in-conduit conductors）, independently or utilized together with other strain measurement methods.展开更多
A fully superconducting electron cyclotron resonance （ECR） ion source （SECRAL ID is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconductin...A fully superconducting electron cyclotron resonance （ECR） ion source （SECRAL ID is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconducting solenoids （Nb-Ti/Cu） and six superconducting sextupoles （Nb-Ti/Cu）. Different from the conventional supercon- ducting ECR magnetic structure, the SEC17AL Ⅱ includes three superconducting solenoid coils＇ that are located inside the superconducting sextupoles. The SECRAL Ⅱ can significantly reduce the interaction forces between the sextupole and the solenoids, and the magnets can also be more compact in size. For this multi-component SECRAL Ⅱ generating its self field of -8 T and being often exposed to the high self field, the mechanical analysis has become the main issue to keep their stress at 〈200 MPa on coils. The analytical and experimental results in mechanics are presented in the SECRAL Ⅱ structure. To improve the accuracy and efficiency of analysis, according to the composite rule of micromechanics, the equivalent uniform windings are used to simulate the epoxy-impregnated Nb-Ti/Cu coils. In addition, using low temperature strain gauges and a wireless fast strain acquisition system, a fundamental experiment on the based on our analysis, the stresses and deformations optimized. strains developments of a sextupole is reported. Finally, for its assembly of each SECRAL Ⅱ coil will be further展开更多
中国科学院近代物理研究所正在研制运行于45 GHz的世界首台第4代电子回旋共振离子源(fourth electron cyclotron resonance,FECR)。该离子源磁体线圈全部采用Nb3Sn(铌三锡)超导材料制作,这一超导材料临界性能对应力敏感,加之磁体中六极...中国科学院近代物理研究所正在研制运行于45 GHz的世界首台第4代电子回旋共振离子源(fourth electron cyclotron resonance,FECR)。该离子源磁体线圈全部采用Nb3Sn(铌三锡)超导材料制作,这一超导材料临界性能对应力敏感,加之磁体中六极线圈和螺线管线圈之间的应力不平衡分布,导致磁铁机械结构设计面临极大挑战。为了验证离子源磁铁结构设计的合理性和仿真结果的可信性,为全尺寸真机的研制奠定技术基础,设计了能够一定程度上反映离子源磁体机械结构的半长度样机。主要介绍了FECR半长度样机的三维机械结构分析,借助ANSYS有限元软件分析了磁铁在室温组装、冷却降温和加电励磁时的应力分布和变化情况,为磁体装配提供预应力参考。展开更多
A conduction-cooled superconducting magnet producing a transverse field of 4 T has been designed for a new generation multi-field coupling measurement system, which will be used to study the mechanical behavior of sup...A conduction-cooled superconducting magnet producing a transverse field of 4 T has been designed for a new generation multi-field coupling measurement system, which will be used to study the mechanical behavior of superconducting samples at cryogenic temperatures and intense magnetic fields. A compact cryostat with a two-stage GM cryocooler is designed and manufactured for the superconducting magnet. The magnet is composed of a pair of flat racetrack coils wound by NbTi/Cu superconducting composite wires, a copper and stainless steel combinational former and two Bi2Sr2CaCu20~ superconducting current leads. The two coils are connected in series and can be powered with a single power supply. In order to support the high stress and attain uniform thermal distribution in the superconducting magnet, a detailed finite element （FE） analysis has been performed. The results indicate that in the operating status the designed magnet system can sufficiently bear the electromagnetic forces and has a uniform temperature distribution.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11302225,11121202 and 11327802the National Key Project of Magneto-Constrained Fusion Energy Development Program under Grant No 2013GB110002the Postdoctoral Science Foundation of China under Grant No 2014M560820
文摘The strain and temperature sensing performance of fiber-optic Bragg gratings （FBGs） with soft polymeric coating, which can be used to sense internal strain in superconducting coils, are evaluated under variable cryogenic field and magnetic field. The response to a temperature and strain change of coated-soft polymeric FBGs is tested by comparing with those of coated-metal FBGs. The results indicate that the coated-soft polymeric FBGs can freely detect temperature and thermal strain, their At variable magnetic field, the tested results indicate accuracy and repeatability are also discussed in detail. that the cross-coupling effects of FBGs with different matrixes are not negligible to measure electromagnetic strain during fast excitation. The present results are expected to be able to provide basis measurements on the strain of pulsed superconducting magnet/cable （cable- around-conduit conductors, cable-in-conduit conductors）, independently or utilized together with other strain measurement methods.
基金Supported by the National Natural Science Foundation of China under Grant No 11302225the China Postdoctoral Science Foundation under Grant Nos 2014M560820 and 2015T81071
文摘A fully superconducting electron cyclotron resonance （ECR） ion source （SECRAL ID is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconducting solenoids （Nb-Ti/Cu） and six superconducting sextupoles （Nb-Ti/Cu）. Different from the conventional supercon- ducting ECR magnetic structure, the SEC17AL Ⅱ includes three superconducting solenoid coils＇ that are located inside the superconducting sextupoles. The SECRAL Ⅱ can significantly reduce the interaction forces between the sextupole and the solenoids, and the magnets can also be more compact in size. For this multi-component SECRAL Ⅱ generating its self field of -8 T and being often exposed to the high self field, the mechanical analysis has become the main issue to keep their stress at 〈200 MPa on coils. The analytical and experimental results in mechanics are presented in the SECRAL Ⅱ structure. To improve the accuracy and efficiency of analysis, according to the composite rule of micromechanics, the equivalent uniform windings are used to simulate the epoxy-impregnated Nb-Ti/Cu coils. In addition, using low temperature strain gauges and a wireless fast strain acquisition system, a fundamental experiment on the based on our analysis, the stresses and deformations optimized. strains developments of a sextupole is reported. Finally, for its assembly of each SECRAL Ⅱ coil will be further
基金the National Natural Science Foundation of China(Grant Nos.11932008 and 12172357)the Key Projects of Guangdong Basic and Applied Basic Research Fund Joint Fund(Grant No.2022B1515120051)+2 种基金the Key Projects of Natural Science Fund of Gansu Province(Grant No.22JR5RA127)the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2022-kb06)Gansu Science and Technology Program.
基金the National Natural Science Foundation of China(Grant Nos.11427904,12025506,and 12172357)the Key Scientific Instruments Development Program of CAS(Grant No.GJJSTD20210007)the Key Projects of Guangdong Basic and Applied Basic Research Fund Joint Fund(Grant No.2022B1515120051).
文摘中国科学院近代物理研究所正在研发第四代ECR(电子回旋共振)离子源FECR(first 4th generation ECR ion source).以20 kW/45 GHz微波加热运行为目标,需要研制Nb_(3)Sn超导磁体以实现对所加热等离子体的有效磁场约束.作为首台采用Nb_(3)Sn超导磁体技术的ECR离子源,FECR的主磁场线圈由4套独立的轴向螺线管线圈与1套径向六极线圈所构成,且均采用单股Nb_(3)Sn线绕制而成,这给线圈的加工、冷体装配、磁体的失超保护等环节带来一系列挑战.为使磁体能在高场、高应力作用下安全稳定运行,项目采用基于铝壳体结构与bladder&key的预紧应力控制技术,完成了一套半尺寸冷体样机的研发.该样机已完成4.2 K低温测试.本项研究的核心关键问题与挑战是如何在复杂的高精度机械装配与高电流强磁场励磁过程中实现对易碎Nb_(3)Sn导线的有效保护.本篇文章中,我们将阐述如何设计、研制、装配及测试工作于复杂磁场与应力环境的高性能Nb_(3)Sn六极磁铁.针对于单个六极线圈的测试,我们设计研发了一种称为“Mirror”结构的测试工装.论文中会详细论述基于壳层结构与bladder&key的装配预紧技术在半尺寸样机上的应用效果.同时,论文对在半尺寸样机上观察到的强烈磁通跳跃现象和它对失超探测保护的严峻挑战问题及相关解决或规避方案进行相关论述.
文摘中国科学院近代物理研究所正在研制运行于45 GHz的世界首台第4代电子回旋共振离子源(fourth electron cyclotron resonance,FECR)。该离子源磁体线圈全部采用Nb3Sn(铌三锡)超导材料制作,这一超导材料临界性能对应力敏感,加之磁体中六极线圈和螺线管线圈之间的应力不平衡分布,导致磁铁机械结构设计面临极大挑战。为了验证离子源磁铁结构设计的合理性和仿真结果的可信性,为全尺寸真机的研制奠定技术基础,设计了能够一定程度上反映离子源磁体机械结构的半长度样机。主要介绍了FECR半长度样机的三维机械结构分析,借助ANSYS有限元软件分析了磁铁在室温组装、冷却降温和加电励磁时的应力分布和变化情况,为磁体装配提供预应力参考。
基金Supported by National Natural Science Foundation of China(11327802,11302225)China Postdoctoral Science Foundation(2014M560820)National Scholarship Foundation of China(201404910172)
文摘A conduction-cooled superconducting magnet producing a transverse field of 4 T has been designed for a new generation multi-field coupling measurement system, which will be used to study the mechanical behavior of superconducting samples at cryogenic temperatures and intense magnetic fields. A compact cryostat with a two-stage GM cryocooler is designed and manufactured for the superconducting magnet. The magnet is composed of a pair of flat racetrack coils wound by NbTi/Cu superconducting composite wires, a copper and stainless steel combinational former and two Bi2Sr2CaCu20~ superconducting current leads. The two coils are connected in series and can be powered with a single power supply. In order to support the high stress and attain uniform thermal distribution in the superconducting magnet, a detailed finite element （FE） analysis has been performed. The results indicate that in the operating status the designed magnet system can sufficiently bear the electromagnetic forces and has a uniform temperature distribution.
