Study on sequential correction of closed orbit distortion of Aichi SR electron storage ring

At Aichi Synchrotron Radiation Research Center (AichiSR), the accelerators are operated from 10 am to 6:30 pm on weekdays. The correction of the closed orbit distortion (COD) of the electron storage ring is performed only once in a day immediately after the transition to 300 mA top-up operation. The closed orbit changes gradually throughout the day due to the temperature change in the accelerator room. We are developing a method to suppress these closed-orbit changes by sequential correction of closed-orbit distortions. To improve the accuracy of the correction, we re-measure the response matrices, which has not been updated since the early stage of the commissioning. We also investigate the optimal number of eigenvalues used in the singular value decomposition. After these efforts, the residual of closed-orbit correction was reduced to about 60 %. (author)