2019_EJRNL_PP_B__RIEMANN_AND_A__STREUN_1.pdf
Terbatas Ratnasari
» ITB
Terbatas Ratnasari
» ITB
A unit cell with one homogeneous bending magnet is commonly used in the design of multi-bend
achromat (MBA) lattices for the new generation of diffraction limited storage rings. But significantly lower
emittance at moderate focusing properties can be achieved by combining longitudinal gradient bends
(LGB) and reverse bends (RB) in a periodic lattice unit cell. LGBs alone, however, are of rather limited
gain. We investigate the emittance achievable for different unit cell classes as a function of the cell phase
advance in a general framework, i.e., with a minimum of assumptions on the particular cell optics. Each
case is illustrated with a practical example of a realistic lattice cell, eventually leading to the LGB/RB unit
cell of the baseline lattice for the upgrade of the Swiss Light Source.