共查询到19条相似文献,搜索用时 93 毫秒
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本文研究了使用Bi-2223/Ag超导带材制备超导闭合线圈的工艺及超导闭合线圈中电流衰减的特性.在闭合线圈焊接点的制作上,分别采用了超导焊接和普通焊锡焊接两种不同方法.通过测量闭合线圈中心点的磁场衰减过程,观察了这两种闭合线圈中电流衰减的特性.实验发现,使用超导焊接技术制备的闭合线圈,电流衰减与时间的自然对数成线性关系,在线圈局部受损伤的情况下,上述关系仍然成立;使用普通焊锡焊接方法制备的闭合线圈,电流衰减不存在上述关系,但也不是时间的e指数函数. 相似文献
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《低温与超导》2017,(12)
无绝缘线圈在各种场合中被广泛地应用和研究。为让超导线圈能够应用于高机械强度负载的场合,超导线圈必须有稳定的机械特性。环氧树脂浸渍是保护超导线圈不受机械扰动的一种常用的增强机械稳定性的方法,但传统的环氧树脂是电绝缘的材料,这可能导致无绝缘线圈的匝间电阻(turn-to-turn contact resistance)变大。因此本文提出了一种新型的浸渍方法,利用导电材料焊锡来浸渍,研究了无绝缘(No-insulation)高温超导线圈焊锡浸渍的可行性。本实验制备了两个线圈来进行对比研究,一个是未浸渍的无绝缘线圈,另一个是用焊锡浸渍后的无绝缘线圈。充放电实验和突然放电实验都在77K的液氮下完成;最后基于集中等效电路,分析了焊锡浸渍对无绝缘线圈的特性电阻及时间延时的影响。 相似文献
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看过贵刊的《关于磁单极子通过超导线圈的讨论》[1](以下简称原文)一文,笔者认为原文至少有2处地方值得商榷.一是超导线圈中的电流I正比于Φ,与普通导体中电流正比于(dΦ/dt)不同.因为超导线圈的特性之一是线圈中的磁通量是不能变的.当有外来的磁通量Φ穿过超导线圈时,线圈中产生电流,电流产生的磁 相似文献
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本文研究了高温超导闭合线圈的重要励磁方式——持续电流开关(persistent current switch).高温超导闭合线圈在各种场合中被广泛地应用和研究.为了使高温超导线圈能够工作在持续电流模式(persistent current mode)下,需要持续电流开关利用超导体在超导状态和电阻状态之间的转换来实现开关状态的切换,而磁控式持续电流开关具有响应速度快、励磁效率较高等优点,因而在闭合超导线圈的励磁中具有广阔应用前景.本文提出一种基于动态阻抗模型的磁控式持续电流开关,将动态阻抗以及磁控式持续电流开关的理论研究与探究实验相结合,深入分析磁控式持续电流开关应用于线圈励磁的影响因素,从而实现动态阻抗的灵活设计以及闭合线圈励磁性能的改善. 相似文献
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设计了一种高温超导平面式梯度计的探测线圈,利用这种探测线圈与超导量子干涉器件(SQ UID)耦合,可以制成二阶或更高阶的高温超导SQUID平面式磁场梯度计.设计的探测线 圈由两个闭合环路组成,每个闭合环路是由若干个环路通过细小的连接通道连接而成.两个 闭合环路由一条超导窄带分割,将SQUID与这条超导窄带耦合可以测出超导窄带上的电流大 小.通过调整各个环路的形状、面积和位置,可以使超导窄带上的电流与磁场的高阶梯度成 正比,从而测得磁场的高阶梯度. 通过计算,得到了各个环路的面积、电感以及位置的关 系,在理
关键词:
高阶平面式磁场梯度计
高温超导薄膜 相似文献
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用于超导储能系统的变压器持续电流开关的研究 总被引:1,自引:0,他引:1
本基于变压器的特性提出了一种能用于超导储能系统的新型超导持续电流开关,即变压器持续电流开关。变压器原边线圈T1的匝数大于副边线圈的匝数,在变压器逼边设置彼此反接的两副边线圈T2和T3以减少开关的电感和避免变压器的铁芯饱和。 相似文献
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Yuan J Rohan ML Shen GX 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2006,182(2):298-307
The use of Bi-2223 high temperature superconducting (HTS) tape as a material for gradient coils in MRI is evaluated in this paper. Bi-2223 tapes have a very high critical current and a very low power loss. A HTS tape gradient coil is expected to provide much higher gradient strength and generate much lower heating than a copper coil. Measurements of the AC power loss of Bi-2223 tapes at typical operating frequencies for gradient coils are presented. The degradation of the critical current and its effect on the increase of AC power loss is analyzed. Practical technical issues such as resistance, gradient strength and mechanical performance are also discussed. A prototype Bi-2223 HTS tape gradient coil is evaluated to verify the concept. 相似文献
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I. A. Al-Omari N. Shaked A. Friedman Y. Wolfus A. Shaulov M. Sinvani Y. Yeshurun 《Physica C: Superconductivity and its Applications》1998,310(1-4):111-115
The interplay between AC and DC currents in a High-Tc Superconducting (HTS) coil, made of multifilamentary silver-sheathed Bi-2223 tape, was investigated. We observed that the application of a small sinusoidal current in the frequency range of 50–500 Hz into the coil, while it is already carrying a DC current in the range of 16–22.5 A, caused an increase in the coil DC voltage. The DC voltage increment due to the AC signal is found to increase linearly with frequency and quadratically with amplitude. The DC voltage increment increases as the coil current grows towards its critical value of 22.2 A. This result may be important in some power applications such as fault current limiters (FCL) and superconducting magnet energy storage (SMES) based on HTS coils. 相似文献
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在建的HL-2M装置的环向场线圈采用了比特板式结构,介绍了采用封闭多边形电流丝模型计算分析HL-2M装置环向场线圈电磁场和纹波情况;环向场线圈电流与环向场引起的电磁力以及与极向场产生的倾覆力也做了计算。计算结果对环向场线圈的设计具有一定的参考意义。 相似文献
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HL-2M������Ȧ��ų��������ļ������ 总被引:1,自引:1,他引:0
在建的HL-2M装置的环向场线圈采用了比特板式结构,介绍了采用封闭多边形电流丝模型计算分析HL-2M装置环向场线圈电磁场和纹波情况;环向场线圈电流与环向场引起的电磁力以及与极向场产生的倾覆力也做了计算.计算结果对环向场线圈的设计具有一定的参考意义. 相似文献
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Induced current of high temperature superconducting loops by combination of exciting coil and thermal switch 下载免费PDF全文
Jia-Wen Wang 《中国物理 B》2022,31(3):37402-037402
With its commercialization, the second-generation (2G) high temperature superconducting (HTS) RE—Ba—Cu—O (REBCO, RE is rare earth) tape is extensively applied to the superconducting magnets in the high magnetic fields. However, unlike low temperature superconducting (LTS) magnets, the HTS magnet cannot operate in the persistent current mode (PCM) due to the immature superconducting soldering technique. In this paper, an exciting method for two HTS sub-loops, so-called charging and load loops, is proposed by flux pump consisting of exciting coil and controllable thermal switch. Two HTS sub-loops are made of an REBCO tape with two slits. An exciting coil with iron core is located in one sub-loop and is supplied with a triangular waveform current so that magnetic field is generated in another sub-loop. The influence of magnetic flux on induced current in load loop is presented and verified in experiment at 77 K. The relationship between the induced magnetic flux density and the current on the sub-loops having been calibrated, magnetic flux density, and induced current are obtained. The results show that the HTS sub-loops can be excited by a coil with thermal switch and the induced current increases with magnetic flux of exciting coil increasing, which is promising for persistent current operation mode of HTS magnets. 相似文献
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从高速动车组用6 .6 MVA 高温超导变压器样机的总体设计和电磁方案出发, 根据国产高温超导线材的性能和结构特点, 开发并掌握了满足变压器样机耐压要求的高温超导线材绝缘包覆工艺, 确定了样机高压和牵引绕组用高温超导线材的截面规格. 在此基础上, 考虑工程化需要, 优化设计了构成绕组的串、 并联饼式线圈, 提出了线圈骨架结构和组装、 串联焊接、 并联线材交叉换位等方案. 之后, 成批试制了实验线圈, 得到了满意的临界电流测量结果, 验证了线圈设计和工程化方案的可行性. 相似文献