Michael Philip C, Park Dongkeun, Choi Yoon Hyuck, Lee Jiho, Li Yi, Bascuñán Juan, Noguchi So, Hahn Seungyong, Iwasa Yukikazu
Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
School of Information Science and Technology, Hokkaido University, Sapporo, Japan.
IEEE Trans Appl Supercond. 2019 Aug;29(5). doi: 10.1109/TASC.2019.2901246. Epub 2019 Feb 25.
We present assembly and test results of a 3-nested-coil 800-MHz (18.8 T) REBCO insert (H800) for the MIT 1.3 GHz LTS/HTS NMR magnet currently under completion. Each of the three H800 coils is a stack of no-insulation (NI) REBCO double-pancake coils (DPs). The innermost 8.7-T Coil 1 (26 DPs) was completed by mid-2016; the middle 5.6-T Coil 2 (32 DPs) was complet-ed in mid-2017; while the outermost 4.5-T Coil 3 (38 DPs) was completed in early 2018. Coils 1, 2 & 3 were assembled together in early 2018 as a 3-nested-coil, the H800, and tested, first in liquid nitrogen to a power supply current of 20 A, followed by testing in liquid helium to a power supply current of 251.3 A, the H800's design operating current. After roughly five minutes settling time at 251.3 A, the H800 quenched. In this paper we examine probable sources of quench initiation and simulate ensuing quench behavior. Remedial efforts to minimize the tendency towards quenching in the H800 are presented and discussed.
我们展示了一个用于麻省理工学院目前正在制造的1.3 GHz LTS/HTS核磁共振磁体的3嵌套线圈800 MHz（18.8 T）REBCO插入件（H800）的组装和测试结果。三个H800线圈中的每一个都是无绝缘（NI）REBCO双饼式线圈（DP）的堆叠。最里面的8.7 T线圈1（26个DP）于2016年年中完成；中间的5.6 T线圈2（32个DP）于2017年年中完成；而最外面的4.5 T线圈3（38个DP）于2018年初完成。线圈1、2和3于2018年初组装在一起成为一个3嵌套线圈H800，并进行了测试，首先在液氮中测试至电源电流为20 A，然后在液氦中测试至电源电流为251.3 A，这是H800的设计工作电流。在251.3 A下经过大约五分钟的稳定时间后，H800发生了失超。在本文中，我们研究了失超起始的可能原因，并模拟了随后的失超行为。还介绍并讨论了为尽量减少H800中失超倾向而采取的补救措施。
