Institute of Modern Physics is developing a Nb3Sn superconducting magnet system for a 45-GHz electron cyclotron resonance ion source. To achieve this complicated and challenging Nb3Sn magnet, a prototype with identical cross section but half the length of the magnet is proposed. A single sextupole coil prototype with 457 mm length has been fabricated and tested. This sextupole coil is 38 mm thick with an aperture of 200 mm. It was wound by using a 1.3-mm diameter Nb3Sn wire insulated with 0.11-mm-thick braided S-2 glass fiber. In order to test the coil in similar conditions than the magnet operation, a sextupole magnetic mirror structure is utilized. The bladder and key technology is employed to exert the required preload on the coil. This article describes the magnetic field design of the sextupole mirror structure, presents the fabrication of the sextupole coil, and reports the cryogenic test results.

中文翻译：

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使用镜面结构测试用于 45-GHz ECR 离子源的原型 Nb3Sn 六极线圈

近代物理研究所正在开发用于 45 GHz 电子回旋共振离子源的 Nb3Sn 超导磁体系统。为了实现这种复杂且具有挑战性的 Nb3Sn 磁体，提出了具有相同横截面但磁体长度一半的原型。一个长度为 457 毫米的单六极线圈原型已经制造和测试。该六极线圈厚 38 毫米，孔径为 200 毫米。它使用直径为 1.3 毫米的 Nb3Sn 线缠绕，并用 0.11 毫米厚的编织 S-2 玻璃纤维绝缘。为了在与磁铁操作类似的条件下测试线圈，使用了六极磁镜结构。气囊和关键技术用于在线圈上施加所需的预载荷。本文介绍了六极镜结构的磁场设计，