Abstract
A statistic error occurred corresponding to the polarization ratio during analysing the measured data of a magnetic domain by using neutron depolarization is presented. The error bar calculated of a fitting curve is strongly related to the polarization ratio but the relevant reports are rare. Therefore, we tried to understand how the polarization ratio affects the error and find out the optimal polarization ratio for the polarized neutron experiments in order to avoid non-necessary efforts on updating the polarization ratio of a polarized neutron beamline, especially for a 3 He polarizer. The accuracy of the data analysis is increased as the polarization ratio increases. However, it's still not necessary to increase the polarization ratio higher than 95% due to the statistical error is already acceptable to the experiments. The experimental result is still barely acceptable (within 5-10% error) after modifying the statistical error within 85% polarization ratio. © 2012 The Physical Society of the Republic of China.