Improvement of the pulsed wire method for undulator magnetic-field measurement

Abstract

The U10 undulator for the Pohang Light Source was measured with a pulsed wire measurement (PWM) method. By adjusting the aperture of the slotted optical switch (SOS) for PWM, the sensitivity of SOS output to the wire displacement improved significantly. A calibration table, which translates the output voltage to the displacement of wire, was obtained and the linearity of the PWM was enhanced using this table. The magnetic-field profile of the U10 undulator measured with the PWM method agrees well with that measured with Hall probe mapping. The effect of the wire dispersion on PWM is also discussed. (C) 2002 American Institute of Physics.