Update of Lattice Design for CEPC Main Ring Yiwei Wang, Yuan Zhang, Chenghui Yu, Jie Gao CEPC AP meeting, 25 Aug 2017

New lattice and DA: bx*=0.36m Longer sextupole in ARC: Lsd=1.2m, Lsf=0.6m Finite length of sextupole in IR: Lhs=Lvs=0.3m, Lsdd=0.1m Finite length of crab sextupole: Lcrab=1.0m

bx*=0.36m IR upstream IR downstream IR geometry

Longer sextupole in ARC DA w/ damping, w/o fluctuation, 100 turns Hard line bx*=0.36m , Lsext=0.4m Dashed line bx*=0.36m, Lsf=0.6m, Lsd=1.2m,

Finite length of sextupole in IR DA w/ damping, w/o fluctuation, 100 turns bx*=0.36m, Lsf=0.6m, Lsd=1.2m, L_IR=0.3m Lsadd=0.1m Hard line, Ls_IR=0.3m, w/ corr Dashed line, Ls_IR=0 DotDashed line, Ls_IR=0.3m w/o corr

w/o corr. sext

Finite length of crab sextupole DA w/ damping, w/o fluctuation, 100 turns bx*=0.36m, Lsf=0.6m, Lsd=1.2m, Ls_IR=0.3m, Hard line, w/o crab Dashed line, w/ carb, Lcrab=0 DotDashed line, w/ carb, Lcrab=1.0m

w/ crab L=0

w/ crab L=1.0m

Beam stay clear region and beam pipe Beam pipe of interaction region Rx=28+7 mm, Ry=28+7 mm Beam pipe of other region Rx=28+7 mm, Ry=43+7 mm

相切椭圆 Rx=43+7 mm Ry=28+7 mm Ftip  R^2/L LSD=0.4m LSD=0.7m LSD=1.2m

Magnets parameters Join the similar magnets in specific region (ARC, STR, RF, IR) Same length Fmax=Max[Abs[Fmax(similar magnets)]] Rgf=Max[Rgf(similar magnets)] Same for D and F Magnets parameters: CEPC_RING_v20170823_Ele_Join_LattInfo_rev2.dat