ReBa2Cu3Odelta-7 (REBCO) coils have the potential to impact a variety of magnet applications but due to slow normal zone propagation velocity (NZPV), quench detection and protection remain difficult. It is therefore important to understand how quench behavior is affected by various aspects of coil design, geometric considerations and material properties. Although past studies have explored the effects of varying the conductor properties, it is important to investigate the influence of insulation as well.;In this study, the effect of insulation properties on three-dimensional (3D) quench propagation in REBCO-based coils is investigated. At present, superconducting magnets primarily use insulators that are electrically and thermally insulating; typically Kapton. Here the impact of electrically insulating, thermally conducting insulators on quench behavior was studied. In particular, the behavior of a Kapton insulated coil was compared to doped-TiO2 and ideal Al2O3 insulated coils. A non-insulated coil was also evaluated. Using a mixed-dimensional model the effect of various insulation materials on multiple quench parameters in REBCO coated conductor coils was studied. The comparison of the usage alternative insulation was conducted for a 20 mum and 100 mum case using three models: Concept Model 1, 2 and 3. Concept model 1 studied the effects on 3D propagation behavior, including the 3D current sharing volume (CSV) and key quench parameters, including minimum quench energy, hotspot temperature and NZPV. Concept model 2 (CM 2) cooled a room temperature coil configuration from room temperature to 50 K for a 15 min duration. The radial and hoop stresses were observed at the cleavage edge, middle height and along the conductor width in the central conductor. Concept model 3 (CM 3) determined the thermal stresses based upon the thermal development of CM 1 during a quench.;Concept model 1 found that ideal Al2O3 insulation resulted in the highest MQE, lowest peak temperature, slowest rate of increase in hotspot temperature, fastest transverse NZPV and smallest CSV. These results indicated that increasing the thermal conductivity of coil insulation can significantly improve coil behavior. Concept model 2 found that doped- TiO 2 and ideal Al2O3 had the most desirable effect by having the most compression within the conductors. The compression present during cool down could lessen the effect of tension during operation. CM 3 showed that NI has less tensile variation between the REBCO layers and could be helpful so that stress is distributed evenly to reduce stress concentrations. Doped -TiO2 had the lower stress values for each insulation thickness. The lower stress is desirable to reduce the risk for delamination.
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机译：ReBa2Cu3Odelta-7（REBCO）线圈可能会影响各种磁体应用，但由于正常区域传播速度（NZPV）缓慢，淬火检测和保护仍然很困难。因此，重要的是要了解线圈设计，几何因素和材料特性的各个方面如何影响淬火行为。尽管过去的研究已经探讨了改变导体性能的影响，但是研究绝缘的影响也很重要。在这项研究中，绝缘性能对基于REBCO的线圈的三维（3D）淬火传播的影响是调查。目前，超导磁体主要使用电绝缘和热绝缘的绝缘子。通常是Kapton。在这里，研究了电绝缘，导热绝缘体对失超行为的影响。特别是，将Kapton绝缘线圈的性能与掺杂TiO2和理想的Al2O3绝缘线圈进行了比较。还评估了非绝缘线圈。使用混合模型，研究了各种绝缘材料对REBCO涂层导体线圈中多个淬火参数的影响。使用三种模型对20毫米和100毫米外壳的替代绝缘的使用进行了比较：概念模型1、2和3。概念模型1研究了对3D传播行为的影响，包括3D电流共享量（CSV）和关键的淬火参数，包括最小的淬火能量，热点温度和NZPV。概念模型2（CM 2）将室温线圈配置从室温冷却到50 K，持续15分钟。在解理边缘，中间高度以及沿中心导体的导体宽度观察到径向和环向应力。概念模型3（CM 3）根据淬火期间CM 1的热发展来确定热应力。概念模型1发现理想的Al2O3绝缘导致MQE最高，峰值温度最低，热点温度增速最慢，横向NZPV最快，CSV最小。这些结果表明，增加线圈绝缘的热导率可以显着改善线圈性能。概念模型2发现，掺杂的TiO 2和理想的Al2O3通过在导体内具有最大的压缩率而具有最理想的效果。冷却过程中出现的压缩可能会降低操作过程中的张力影响。 CM 3表明，NI在REBCO层之间的拉伸变化较小，并且可能有助于应力均匀分布以降低应力集中。掺杂的-TiO 2对于每种绝缘厚度具有较低的应力值。需要较低的应力以减少分层的风险。
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