小孔径多极磁铁磁场测量技术研究

Magnetic field measurement is an important method to test the quality of the magnet, which provides quality supervision for magnet production and important parameters for accelerator operation. With the development of new accelerator technology, the complete and accurate measurement of multipole magnet with small aperture and long equivalent magnetic length is one of the technical problems that need to be solved urgently. In order to solve this problem, a complete magnetic field measurement method based on the technique of stretched-wire will be studied. Stretched-wires will be used as the magnetic field measurement probe. By optimizing the trajectory of the wire in the aperture of magnet and analyzing the voltage induced from the stretched-wire, the complete and accurate information of the magnetic field can be obtained. Through the study of this subject, it not only can solve the measurement problem of multipole magnet with small aperture and long equivalent magnetic length, but also can study the magnetic field at the region of the magnetic pole, which is very important for the determination of the magnet good field region(optimize the magnet aperture), and that will be beneficial to the further development of the accelerator magnet technology.

磁场测量是检验磁铁质量的重要手段，它为磁铁生产提供质量监督和加速器运行提供重要参数。随着新加速器技术发展趋势，小孔径、长等效磁长度多极磁铁完整、精确的测量是亟需解决的技术难题之一。为解决该难题，本基金课题基于张力线技术研究一种完整的磁场测量方法。它以张力线为磁场探针，通过优化磁铁孔径中的张力线运动轨迹，并对它们切割磁力线时感应的电压信号进行分析，从而获得磁场完整、准确的信息。通过本课题的研究，不仅能够解决小孔径、长等效磁长度这种类型磁铁的精确测量难题，而且还可对磁铁极头区域磁场进行研究，这对磁铁好场区范围的界定有着重要参考价值(优化磁铁孔径大小)，将有利于磁铁技术的进一步发展。

磁铁是加速器重要和基本的部件之一。无论直线加速器，环形加速器或者其它类型的加速器，带电粒子加速到高能量必须要保持轨道稳定性。而各种类型的磁铁为粒子束流提供了不同需要的磁场力。由于存在系统偏差、磁材料性能差异以及机械加工误差等，多极磁铁存在高次谐波、磁中心偏差、安装误差等一系列误差。而磁场质量好坏对加速器的运行起着至关重要的作用，影响束流的品质。. 磁场测量是检验磁铁质量的重要手段，它为磁铁生产提供质量监督和加速器运行提供重要参数。本课题研究了一种基于张力线的磁场测量方法。首先研制了一套多维移动机械平台，该平台两端的执行机构可带动张力线同步进行水平、垂直和旋转运动。其次研制了一个可灵活调整张力线旋转半径的转动平台。借助该平台对张力线进行180度翻转，在翻转前后通过测量磁中心变化值对张力线旋转半径进行校准。再次通过灵活改变张力线旋转半径进行测量验证了空间谐波分布规律。最后对最小二乘法数据处理流程进行了研究。. 通过本课题的研究，不仅验证了张力线不仅可用于谐波测量而且具有更高的线圈制作精度，而且也摸索出了一种基于张力线的测量方案，同时也对空间谐波分布的规律进行了验证，这对磁场测量技术的发展具有重要意义。