Low emittance lattice design for Korea-4GSR

Abstract

The lattice type of Korea 4th Generation Storage Ring (Korea-4GSR) is determined as hybrid multi-bend achromat type (HMBA) after a comparison of three types of multi-bend achromat (MBA) lattices because HMBA provides sufficiently low beam emittance and good nonlinear beam dynamics with the smallest number of sextupole magnets among the three types of lattices. We also propose the use of bending beamlines with 2 T centre bending magnets (CBMs). Considering the determined lattice type, longitudinal gradient bending magnets and reverse bending magnet were used to reduce the emittance and use of damping wigglers is being considered to reduce emittance further. The ring design result shows that the natural emittance of Korea-4GSR is 58 pm and can be reduced 28% by adopting damping wigglers. Linear and nonlinear dynamics aspects of Korea-4GSR including intrabeam scattering simulation is demonstrated and error effects on Korea-4GSR were also investigated.