To obtain high luminosity, compact high gradient quadrupole magnets QD0 and QF1 are required on both sides of the interaction points of the proposed Circular Electron Positron Collider (CEPC). QD0 is a double aperture superconducting quadrupole closest to the interaction point with a crossing angle between two aperture centerlines of 33 mrad. Magnetic field crosstalk between two apertures of QD0 is negligible using iron yoke, and the 3D coil end is optimized by ROXIE. In the design study, both NbTi conductor and HTS conductor are taken into account. The first step of the R&D is to design and manufacture a QD0 short model magnet with a magnetic length of 0.5 m. In this paper, the R&D status of QD0 short model magnet is described, and the design study of quadrupole magnet including NbTi technology and HTS Bi-2212 technology is presented.

中文翻译：

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CEPC相互作用区超导四极磁体研发

为了获得高亮度，在所提议的圆形电子正电子对撞机 (CEPC) 的相互作用点的两侧都需要紧凑的高梯度四极磁体 QD0 和 QF1。QD0 是最靠近相互作用点的双孔径超导四极杆，两个孔径中心线之间的交叉角为 33 mrad。QD0的两个孔径之间的磁场串扰使用铁轭可以忽略不计，3D线圈端由ROXIE优化。在设计研究中，NbTi 导体和 HTS 导体都被考虑在内。研发的第一步是设计制造磁长为0.5m的QD0短型磁体。本文介绍了QD0短型磁体的研发现状，提出了包括NbTi技术和HTS Bi-2212技术的四极磁体的设计研究。