A TME-like Lattice for DA Studies Fanglei Lin, Yuri Nosochkov, Min-Huey Wang, Vasiliy Morozov, Guohui Wei, Yuhong Zhang January 17, 2017 F. Lin

Complete e-Ring Optics Ring geometry is matched. Circumference 2276.58 m = 2 x 925.17 m arcs + 2 x 213.11 m straights. Normalized emittance @ 5 GeV: 30.9 um-rad w/o SBCCBs and 29.4 um-rad w/ SBCCBs. (geometric emittances are 3.2 and 3 nm-rad, respectively) IP w/ sextupoles w/o sextupoles

Suggestions from Yuri in Last Meeting Reduce the beta functions in the two additional CCBs Considering using non-interleaved sextupole pairs in the arcs Maybe use sextupoles in additional CCBs

Suggested Plan for e- Ring DA Studies Optimize the superB-like compensation scheme for a better emittance control (done) Match the ring’s geometry (with new-magnet TME-like-arc-cell first) and check the DA Good, do the following studies (for the FODO-arc-cell ring too?) Bad, go back to the FODO-arc-cell ring and do the following studies Replace the thin lens phase/tune trombones with actual quadrupole adjustment and verify the chromatic correction performance Optimize betatron tunes by doing the tune scan Study effects of misalignment and field errors on the dynamic aperture, develop a correction scheme using BPMs and correctors included (or added/removed), specify alignment and strength error tolerances Study impact of multipole fields in regular magnets (using PEP-II specs) on the dynamic aperture Determine FFQ multipole tolerances following the same procedure as for the ion collider ring From the DA meeting on Nov. 22 2016

Back Up

TME-like Arc Cell Arc TME-like cell Dipole Quadrupoles Sextupoles Length 22.8 m (same as ion ring arc cell) arc bending radius 155.45 m (same as in the baseline) 270/90 x/y betatron phase advance Dipole Magnetic/physical length 4.0/4.28 m Bending angle 36.7 mrad (2.1), bending radius 109.1 m 0.31 T @ 10 GeV (0.37 @ 12 GeV) Sagitta 1.83 cm Quadrupoles Magnetic/physical length 0.56/0.62 and 1.0/1.06 m 20 T/m field gradients @ 10 GeV (24 T/m @ 12 GeV) 1.0 T @ 50 mm radius @ 10 GeV (1.2 T @ 12 GeV) Sextupoles Magnetic/physical length 0.25/0.31 m BPMs and Correctors Physical length 0.05 and 0.25 m

SuperB-like CCB Similar to Yuri’s dipole bending angle of qb = 5/7 qb0 = 0.714 qb0, I used qb = 4/7 qb0 = 0.571 qb0 Yuri’s Scheme-6

Arc Spin rotator + SuperB CCB + Arc cells

Updated IR Region

W Functions W functions for the ring with tunes at (66.22, 35.16), without chromaticity compensation.

W Functions W functions for the ring with tunes at (66.22, 35.16), with chromaticity compensation.

Chromatic Tunes and Beta-stars K2l: ksxsbcc1 = 1.808331247 ; K2l: ksxsbcc2 = -5.638074023 ; K2l: ksxsbcc1l = -1.839318844 ; K2l: ksxsbcc2l = 3.19542572 ; K2: ksxtarc01 = 14.71256876 ; K2: ksxtarc02 = -22.91644959 ; L = 0.25m

Schemes summary ex (nm) qb / qb0 b at CCB sext, x/y 1 @ 5 GeV Lb / Lb0 No CCB 1 2 3 4 6 ex (nm) @ 5 GeV 8.9 29.3 22.8 12.2 10.3 8.3 qb / qb0 2.286 1.429 1.286 0.714 Lb / Lb0 0.5 0.592 b at CCB sext, x/y --- 300 / 600 200 / 400 K2Lmax (m-2) CCB 0.78 1.04 3.06 3.44 3.53 K2Lmax (m-2) arcs 3.09 2.94 2.84 1.87 1.90 2.53 Natural x, x/y -113 / -120 -129 / -147 -123 / -136 -132 / -155 -132 / -156 -135 / -152 Tune, x/y 44.22 /47.16 44.22 /45.16 45.22 /47.16 46.22 /47.16 48.22 /50.16 C (m) 2185.5 2182.8 2182.4 2181.7 2327.2 Comment 60x2 arc sextupoles Thin trombones for match, 40x2 arc sextupoles Thin trombones for match, 60x2 arc sextupoles Thin trombones, for match, 60x2 arc sextupoles No trombones, longer arc, 60x2 arc sextupoles From Yuri’s JLEIC collaboration meeting fall 2016 * Ring geometry is not yet matched in these CCB schemes