1. 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

2. Complete e-Ring Optics
Ring geometry is matched.
Circumference m = 2 x m arcs + 2 x m straights.
Normalized 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

3. 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

4. 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

5. Back Up

6. TME-like Arc Cell Arc TME-like cell Dipole Quadrupoles Sextupoles
Length 22.8 m (same as ion ring arc cell)
arc bending radius 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 m
GeV 12 GeV)
Sagitta 1.83 cm
Quadrupoles
Magnetic/physical length 0.56/0.62 and 1.0/1.06 m
20 T/m field 10 GeV (24 12 GeV)
mm 10 GeV ( GeV)
Sextupoles
Magnetic/physical length 0.25/0.31 m
BPMs and Correctors
Physical length 0.05 and 0.25 m

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

8. Arc
Spin rotator + SuperB CCB + Arc cells

9. Updated IR Region

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

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

12. Chromatic Tunes and Beta-stars
K2l: ksxsbcc1 = ;
K2l: ksxsbcc2 = ;
K2l: ksxsbcc1l = ;
K2l: ksxsbcc2l = ;
K2: ksxtarc01 = ;
K2: ksxtarc02 = ;
L = 0.25m

13. 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