合肥光源1 nm发射度的储存环初步物理设计研究

Preliminary Physics Design of Storage Ring for Hefei Light Source With 1 nm Emittance

针对合肥光源未来升级为纳米级发射度储存环的计划,设计了一个紧凑的H6BA lattice物理方案。在800 MeV束流能量下,自然发射度为1.2 nm·rad,达到了所辐射的极紫外光的衍射极限发射度。考虑误差效应的6D动力学孔径在水平正方向上大于20 mm,可满足离轴注入的需要。由于束流能量和发射度均较低,束内散射和Touschek效应显著,考虑10%耦合情况下,平衡发射度增长了约50%,Touschek寿命为4.2 h,采用全耦合模式可较为有效地抑制这2种效应。

A physics design based on a compact H6BA lattice is studied for the future upgrade of the Hefei Light Source storage ring with the goal of nanoscale emittance.In this design,the natural emittance is 1.2 nm·rad at a beam energy of 800 MeV,which reaches the diffraction limited emittance of EUV synchrotron radiation.The 6D dynamic aperture with error effect is larger than 20 mm in the positive horizontal direction,which is sufficient for an off-axis injection.Due to both low beam energy and low emittance,the intra-beam scattering and Touschek effects are significantly strong.The equilibrium emittance is increased by about 50%at a coupling of 10%,and the Touschek lifetime is 4.2 hours.The two effects can be effectively suppressed in the full-coupling mode.The physics design of the storage ring can also provide a reference for the upgrade of the same type of light source.