Arpaia P, Buzio M, Golluccio G, Walckiers L
Department of Engineering, University of Sannio, Benevento, Italy.
Rev Sci Instrum. 2012 Jan;83(1):013306. doi: 10.1063/1.3675578.
An in situ procedure for calibrating equivalent magnetic area and rotation radius of rotating coils is proposed for testing accelerator magnets shorter than the measuring coil. The procedure exploits measurements of magnetic field and mechanical displacement inside a reference quadrupole magnet. In a quadrupole field, an offset between the magnet and coil rotation axes gives rise to a dipole component in the field series expansion. The measurements of the focusing strength, the displacement, and the resulting dipole term allow the equivalent area and radius of the coil to be determined analytically. The procedure improves the accuracy of coils with large geometrical irregularities in the winding. This is essential for short magnets where the coil dimensions constrain the measurement accuracy. Experimental results on different coils measuring small-aperture permanent magnets are shown.
提出了一种用于校准旋转线圈等效磁面积和旋转半径的原位程序，以测试比测量线圈短的加速器磁铁。该程序利用参考四极磁铁内部的磁场和机械位移测量。在四极场中，磁铁和线圈旋转轴之间的偏移会在磁场级数展开中产生偶极分量。聚焦强度、位移以及由此产生的偶极项的测量允许通过解析确定线圈的等效面积和半径。该程序提高了绕组几何形状不规则较大的线圈的精度。这对于短磁铁至关重要，因为线圈尺寸会限制测量精度。展示了在测量小孔径永磁体的不同线圈上的实验结果。
