Analysis of resonance lines and working points of the HALF storage ring lattice

The Hefei Advanced Light Facility (HALF) storage ring employs a hybrid six-bend achromat lattice with long and short straight sections. In this paper, main resonance lines of on- and off-momentum dynamic apertures (DAs) of the HALF lattice are analyzed by using frequency map analysis and considering $\beta$-beat. The combined effect of a fifth-order structural resonance and a half-integer non-structural resonance can induce notable particle loss in off-momentum DAs over a certain range of negative energy deviations. However, it has a limited impact on local momentum aperture even with relatively large $\beta$-beat. Using the analysis of resonance driving term fluctuations, the HALF lattice with a new working point is studied, which exhibits a significantly improved 6D DA in the direction of beam injection.