Storage Ring

Novel hybrid 6BA lattice design and technology

The HALF storage ring consisting of 20 identical lattice cells uses a novel hybrid 6BA lattice, which replaces the three combined-function bend unit cells of the typical hybrid 7BA lattice with two LGB-RB unit cells  (LGB: longitudinal field gradient bending magnet, RB: reverse bending magnet) and a mid-straight section. This novel lattice design has a superior ability to reduce both beam emittance and damping times while providing more straight sections for insertion devices. The length of the long straight section is 5.3 m, and the mid-straight section is 2.2 m long. The natural emittance is 86 pm·rad at 2.2 GeV. To further reduce the damping times and beam emittance, two damping wigglers are employed. The beam energy is considered to increase to 2.4~2.5 GeV in the future. The large dynamic aperture allows for off-axis injection.