HIGHLY AUTOMATIC-MEASUREMENT SYSTEM FOR 3 ORTHOGONAL MAGNETIC-MOMENTSOF A PERMANENT-MAGNET BLOCK

A highly automatic system with a three-angle rotation mechanism has be en designed and constructed to measure several thousand permanent magn et blocks. The system's main features include its high speed, highly a utomatic measurement, and the ease with which the different size magne t blocks can be installed and removed. This system provides precise an d accurate measurements of the three orthogonal magnetic moment compon ents to accurately characterize each block, as deemed necessary to ass ess the field quality of undulators and wigglers. A three-angle in rot ation mechanism, together with a simple mathematical algorithm is used to measure and analyze the magnetic moments of the magnet block. The system includes the Helmholtz coil pair, block holder, the three-degre e rotation mechanism, and the control and data acquisition system. A p ower train system consists of one motor coupled with a nonmagnetic sta inless steel for 360 degrees rotation and two motors individually coup led with two groups of nonmagnetic time belts for rotation angles of 0 degrees, 180 degrees, 0 degrees, and 90 degrees. The control system u ses a microcomputer together with a stepping motor control card and a digital fluxmeter connected by the general purpose interface bus. The measurement speed of this system is 40 blocks per h. One reference mag net was measured, with those results verifying the long term precision of the order of 0.04% for the easy component and 0.02 degrees for two minor components. The coil-pair geometry factor is calibrated via the voltage-field reciprocity principle, indicating that the system absol ute accuracy is around 0.43%. (C) 1996 American Institute of Physics.