Exploring lattice candidates for TPS upgrade

The design of lattice candidates for the Taiwan Photon Source (TPS) upgrade is under investigation, focusing on Multi-Bend Achromat (MBA) and Hybrid Multi-Bend Achromat (HMBA) configurations. A 5BA lattice, which offers relaxed hardware requirements, can achieve a natural beam emittance in the hundred pm-rad range for a 3 GeV storage ring. The 6BA configuration shows promise in achieving phase cancellation without the need for harmonic sextupoles but presents challenges due to limited available space. The HMBA scheme is attractive for its simpler configuration and reduced reliance on nonlinear magnets. Preliminary results highlight the characteristics and trade-offs of each configuration, providing guidance for the future TPS upgrade.