Standard in situ type MgB₂ strands manufactured by Hyper Tech, Inc., have 19-36 subelements, a Monel outer sheath, and a Cu interfilamentary matrix. Typical transport J_cs of the strands are 2 × 10⁵ A/cm² with n-values of 20-30 at 4.2 K and 5 T. This paper introduces two new MgB₂ conductor designs. First, a new class of MgB₂ strand is designed for magnetic resonance imaging applications. This type has a higher Cu content designed to enhance protection of a magnet wound with it, and a larger diameter to increase the critical current. Second, a new class of low ac loss MgB₂ strand with high filament count and a high-resistance matrix is discussed. Transport properties at 4.2 K and fields up to 10 T are reported. Optical techniques are used to study the macro and microstructures of these MgB₂ strands.

中文翻译：

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用于 MRI 和低交流损耗应用的多丝 MgB2 股线的结构和传输特性

由Hyper Tech, Inc.制造的标准原位型MgB ₂股线具有19-36个子元件、蒙乃尔合金外护套和铜丝间基体。绞线的典型输运 J _{c s 为 2 × 10} ⁵ A/cm ^{2 ，}在 4.2 K 和 5 T 下 n 值为 20-30。本文介绍了两种新的 MgB ₂导体设计。首先，新型 MgB ₂链专为磁共振成像应用而设计。这种类型具有较高的铜含量，旨在增强对其缠绕的磁体的保护，并且具有较大的直径以增加临界电流。其次，讨论了具有高细丝数和高电阻基体的新型低交流损耗MgB _2股线。报告了 4.2 K 和高达 10 T 场的输运特性。光学技术用于研究这些 MgB ₂线的宏观和微观结构。