Lattice model calibration of Hefei light source storage ring

To abstract linear optics of storage ring, response matrix fitting technique was developed as an advanced diagnostic tool of storage ring. The Matlab-based LOCO (Linear Optics of Closed Orbit) was a representative of response matrix fitting codes. Recently, in order to get accurate lattice model of storage ring, LOCO was applied to Hefei light source. In this paper, firstly the principle of response matrix fitting was briefly reviewed and the numerical simulation of application of LOCO to HLS storage ring and the simulation results were introduced. Through numerical simulation, the effect of BPM noise level on accuracy of fitting results was demonstrated. Finally, experimental results made at Hefei light source to calibrate focusing strength of quadrupoles and edge focusing strength of dipoles by LOCO were described. Some measures were taken to reduce systematic errors, and the fitting results agreed well with the magnetic measurement results of the backup quadrupole and dipole. Based on the fitting results, a lattice model of HLS storage ring was established and it could describe real storage ring more accurately. (authors)