Lattice design of Beijing Light Source

In this paper, the preliminary design of the magnet lattice of the Beijing Light Source (BLS) is described. The Beijing Light Source is a new generation light source with the energy of 2.2 GeV-2.5 GeV. By choosing the FBA (five bend achromat) and TBA (triplet bend achromat) structure very low horizontal emittance is reached using superconducting dipole magnets. Having made some harmonic corrections, an acceptable dynamic aperture is obtained though further improvement is being done to enlarge the horizontal aperture.