Design of a hybrid ten-bend-achromat lattice for a diffraction-limited storage ring light source

The hybrid multi-bend achromat (MBA) lattice concept, proposed by ESRF EBS, has been used in some diffraction-limited storage ring (DLSR) designs due to both the lower emittance and the better nonlinear performance achieved. In this paper, to reduce the emittance for a given storage ring circumference, we extended the hybrid MBA lattice from the typical hybrid 7BA to a hybrid 10BA with three additional combined function bending magnets in the lattice center, since the emittance scales inversely with the third power of the number of bending magnets. For the hybrid 10BA lattice, two kinds of phase advances between dispersion bumps have been studied in designing a DLSR with an energy of 2.4 GeV and a circumference of 324 m. The dynamic aperture of the designed DLSR with a natural emittance of 120$\sim$130 pm$\cdot$rad is large, and the momentum aperture is also acceptable.