LOGO CEPC Partial Double Ring Lattice SPPC Lattice

LOGO CEPC Partial Double Ring Lattice & SPPC Lattice Design Feng Su Jie Gao Jingyu Tang Dou Wang Yiwei Wang Tianjian Bian Sha Bai Huiping Geng Yuan Zhang Yuanyuan Guo Yuemei Peng Ye Zou The first IHEP-BINP CEPC Accelerator Collaboration Workshop Jan 12 -13, 2016

Outline 1. CEPC Partial Double Ring Lattice 2. SPPC Lattice

1. CEPC Partial Double Ring Lattice

CEPC Partial Double 1/2 RF Ring Layout 1/2 RF IP 1_ee RF RF 3. 2 Km 1/2 RF Bypass about 42 m 1/2 RF IP 4_pp IP 2_pp 1/2 RF IP 1_ee/IP 3_ee, 3. 2 Km IP 2_pp/IP 4_pp, 1132. 8 m 4 Short Straights, 141. 6 m Bypass about 42 m C=59044 m RF RF IP 3_ee 4 Medium Straights, 566. 4 m 4 Long Straights, 849. 6 m 2 Short ARC, 24*FODO, 1132. 8 m 4 Medium ARC, 112*FODO, 5286. 4 m 4 Long ARC, 124*FODO, 5852. 8 m 1/2 RF SU Feng 2016. 1. 4

CEPC Partial Double Ring Layout CEPC Partial Double Ring By MADX and PTC Blue: Bend Green: Straight Section Bypass C=59044 m Bypass SU Feng CEPC Partial Double Ring 2016. 1. 4

CEPC Partial Double Ring Layout 12 62. 5 urad B 2 4. 5 m 0. 75 mrad in total B 1 m 54 m Septum Dipole Separator 7 30 B 3 47 9. 1 614. 4 m m . 2 Full crossing angle 26 mrad 13 mrad 7. 852 m B 6 IP Septum Dipole 1642 m B 4 For CEPC 120 Ge. V beam: ØMax. deflection per separator is 66μrad. Using Septum Dipole after separator to acquire 13 mrad B 5 Version 1. 0 sufeng 2015. 12. 20

Separator with Thin Septum Magnet Sigmax=697. 8 um 20 sigma=14 mm 20 mm Beam dump Septum Magnet：L=3 m Separator： 62. 5 urad 12 个 0. 75 mrad （4. 25 mrad）thicknes=3 -5 mm rho=705. 822 m B=0. 56 T

Orbit difference between dipole separator kicker Dipole Seperator Kicker 0. 025 0. 02 0. 015 0. 01 0. 005 0 0 20 40 X=20. 25 mm 60 X=20. 25 mm

0. 025 0. 02 X（m） 0. 015 dipole seperator 0. 01 kicker 0. 005 0 0 10 20 30 40 50 S（m） 60 0 60 s（m） -0. 005 DX -0. 015 dipole separator kicker -0. 025 So we use Dipole instesd Seperator in lattice now

SEPARATIONMATCHL Beta<150 m

RING 3_DR_IP 1_2

Orbit (RING 3_DR_IP 1) Version 1. 0 without FFS 10 8 6 4 2 0 -4 -6 -8 -10 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400

Dipole Strength Version 1. 0 without FFS Angle(mrad L(m) ) Rho(m) Brho(E 0/ c)(T/m) B(T) Ek(Ke. V) Ke. V/m B 0 3. 232 19. 6 6064. 36 400 0. 06596 631. 625 32. 226 BSep. L -0. 0625 4. 5 -72000 400 -0. 00556 53. 2 11. 822 BSeptum. L -4. 25 3 -705. 822 400 -0. 56667 5426. 4 1808. 8 BMatch 1 L -0. 469 4. 9 -10447. 8 400 -0. 03829 366. 624 74. 821 BMatch 2 L -3. 171 19. 6 -6181. 02 400 -0. 06471 619. 704 31. 618 BMatch 3 L -4. 36 19. 6 -4495. 41 400 -0. 08898 852. 069 43. 473 B 2 2. 167 19. 6 9044. 76 400 0. 04422 423. 494 21. 607 B 3 2. 167 19. 6 9044. 76 400 0. 04422 423. 494 21. 607 B 4 -2. 167 19. 6 -9044. 76 400 -0. 04422 423. 494 21. 607 B 5 -2. 167 19. 6 -9044. 76 400 -0. 04422 423. 494 21. 607 BMatch 3 R 4. 36 19. 6 4495. 41 400 0. 08898 852. 069 43. 473 BMatch 2 R 3. 171 19. 6 6181. 02 400 0. 06471 619. 704 31. 618 BMatch 1 R 0. 469 4. 9 10447. 8 400 0. 03829 366. 624 74. 821 BSeptum. R 4. 25 3 705. 822 400 0. 56667 5426. 4 1808. 8 BSep. R 0. 0625 4. 5 72000 400 0. 00556 53. 2 11. 822

Survey & Dynamic Aperture （Version 1. 0 –without FFS） Bypass part at IP 2/4 0: 20σx 700σy 0. 01： 16σx 500σy 0. 02： 10σx 170σy

Dynamic Aperture Comparation 0: 20σx 700σy 0. 01： 16σx 500σy 0. 02： 10σx 170σy 0: 50σx 1500σy 0. 01： 50σx 900σy 0. 02： 40σx 800σy CEPC Partial Double Ring Lattice CEPC Main Ring Lattice (without pretzel) (Version 1. 0 -20160104) (September 30, 2014 Geng Huiping)

CEPC-Single CEPC-PDR-Bypass CEPC-Single-Bypass CEPC-PDR-Bypass-PDRn. Pi

FFS Part Crab sextupoles IP -I Y: 2. 5 Pi X: 2 Pi K 2=-126. 77 Wangdou-20151216

Sufeng-20151224 K 2=-48. 57 Wangdou-20151216 K 2=-126. 77

Orbit of FFS Part

Orbit (RING 3_DR_IP 1) Version 1. 0 + FFS(20151126) 10 8 6 4 2 0 -4 -6 -8 -10 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400

Tune/DA with FFS 0: 13σx 55σy 0. 01： 0 0. 02： 0 For details： Energy spread between -0. 8628% and 0. 719% has DA, out is 0.

Optimize 1、We tried to add sextupoles here, but not help for DA. Because it’s not easy to match the phase advance between them. 2、Try to add some Sextupoles to correct high order chormaticity here.

DA Comparation CEPC-PDR-Bypass-Sex

Summary for part 1 u The first version of CEPC Partial Double Ring Lattice was designed (Version 1. 0). The whole length of CEPC PDR is 3281. 27 m, full crossing angle is 26 mrad, maximum distance between two ring is 14. 913 m. u The Dynamic Aperture need to be optimized. Now the DA of CEPC with PDR and Bypass(at IP 2/4) and without FFS is better than before, but the DA with FFS is not good enough. u We may add more sextupoles in PDR to correct the high order chromaticity , or use more group of sextupoles in ARC to optimize the DA. u The linear lattice of PDR may also be optimized.

2. SPPC Lattice

AR 1 C 8 C 1 AR SPPC Layout 2 LSS 1_ee P. S. （Su Feng, Jul. 10, 2015） arccell 2 arccell 1 LSS 8_extr P. S. LSS 2_inj C 78 AR 23 ARC arccell 2 arccell 1 LSS 3_pp LSS 7_pp C = 55. 025 km arccell 1 arccell 2 7 LSS 2/4/6/8 : 938. 6 m LSS 3/7 : 1070. 89 m ARC 5920. 4 m C 3 4 LSS 6_coll LSS 4_coll arccell 2 P. S. arccell 1 LSS 5_ee AR C 56 AR C 6 AR LSS 1/5 : 1083 m AR 5 4 C

Layout of two CEPC lattices Huiping Geng

Consideration of CEPC New Layout with PDR

SPPC Layout （Su Feng Jan. 10, 2016） AR C 1 1 C 8 R A 2 LSS 1_coll P. S. arccell 2 arccell 1 LSS 8_extr P. S. LSS 2_inj C 78 AR 23 ARC arccell 2 arccell 1 LSS 3_pp LSS 7_pp C = 58. 983 km arccell 1 arccell 2 ARC: 5963. 2 m C 3 LSS 4_RF arccell 2 P. S. arccell 1 LSS 5_coll AR C 5 6 AR LSS 6_RF 7 LSS 3/7_pp: 973. 83 m C 6 LSS 2/4/6/8： 788. 31 m 4 AR LSS 1/5_coll ： 3. 2 Km 45 C AR

Parameter Estimate for ARC CELL High Field Dipole in Pre-CDR ： 20 T，15 m

FODO CELL in ARC arccell 1 L=144. 4 m Betax: 244. 878/42. 57 Betay: 42. 569/244. 869 arccell 2

ARC CELL LQ DQS LS DSB LB DBB 4 m 1 m 0. 5 m 1 m 14. 8 m 1 m 6. 3137 m 1 m 0. 5 m 2. 184 m 14. 3 m 1. 36 m SPPC FCC-hh B max [T] G max [T/m] k 1 19. 61 582. 156 4. 9899 E-3 k 2 Betax: 244. 878/42. 57 Betay: 42. 569/244. 869 0 Pre-CDR： Dipole: L=15 m B=20 T Quadrupole: D = 45 mm Bpole=16 T G=711. 1 T/m K 1=6. 097*10^-3

ARC （ARCDSPL, 36 CELL, ARCDSPR） ARC 23 ARC 45 ARC 67 ARC 81 L=5963. 2 m ARC 12 ARC 34 ARC 56 ARC 78

Dispersion Suppressor (DS) types IP ARC Half Bend (1) 14. 3 m 8. 33 T 433. 2 m 13. 5 m 7. 74 T (half weak dipoles) (2) LHC-like (3) Full Bend Longer DS but less cells in the Arcs

L=288. 8 m BDSP 1 L BDSP 2 L BDSP 1 R BDSP 2 R B 0 (1) 9. 93 19. 86 (T) (2) 18. 93 19. 86 (T) (3) 19. 86 (T)

Dispersion Suppressor (DS) BDSP 1 L BDSP 2 R BDSP 2 L BDSP 1 R 382. 4 m BDSP 1 L BDSP 2 L BDSP 1 R BDSP 2 R B 0 B 18. 93 19. 86 T L 11. 5 14. 8 m

Long Straight Section SPPC Layout （Su Feng Jan. 10, 2016） AR C 1 1 C 8 R A 2 LSS 1_coll P. S. arccell 2 arccell 1 LSS 8_extr P. S. AR arccell 2 arccell 1 23 ARC C 78 LSS 2_inj LSS 3_pp LSS 7_pp C = 58. 983 km arccell 1 arccell 2 ARC: 5963. 2 m C 3 LSS 4_RF arccell 2 P. S. arccell 1 LSS 5_coll AR C 5 6 AR LSS 6_RF 7 LSS 3/7_pp: 973. 83 m C 6 LSS 2/4/6/8： 788. 31 m 4 AR LSS 1/5_coll ： 3. 2 Km 45 C AR

LSS 1/5_coll L=3243. 106 m ARCDSPL, ARC_to_STR, 21. 5*STRCELL, STR_to_ARC, ARCDSPR 382. 4 m, 71. 719 m, 3104. 6 m, 66. 789 m, 382. 4 m

LSS 2_inj/LSS 8_extr L=788. 306 m -ARCDSPR, ARC_to_STR, 4. 5*STRCELL, STR_to_ARC, -ARCDSPL 382. 4 m, 71. 719 m, 649. 8 m, 66. 787 m, 382. 4 m

LSS 4/6_rf L=788. 306 m -ARCDSPR, ARC_to_STR, 4. 5*STRCELL, STR_to_ARC, -ARCDSPL 382. 4 m, 71. 719 m, 649. 8 m, 66. 787 m, 382. 4 m

LSS 3_pp/LSS 7_pp L=973. 829 m ARCDSPL, ARC_to_STR, 21. 5*STRCELL, STR_to_ARC, ARCDSPR 382. 4 m, 71. 719 m, 973. 829 m, 66. 789 m, 382. 4 m

Q Strength K 1(m^-2) G（T/M） L(M) βmax K 1. QT. 1 R 4. 9751 e-03 580. 428 6 3543. 69 K 1. QT. A 2 R -5. 2595 e-03 -613. 668 9 9601. 686 K 1. QT. B 2 R -5. 2595 e-03 -613. 668 9 9601. 686 IR: K 1. QT. 3 R 5. 3434 e-03 623. 369 8 9731. 53 D = 60 mm Bpole = 20 T K 1. QM. 4 R -2. 2804 E-04 -266. 04 4 3798. 29 K 1. QM. 5 R 8. 8592 E-04 103. 36 4 1506. 53 G=666. 7 T/m K 1=5. 716*10^-3 K 1. QM. 6 R -1. 2144 E-03 -141. 68 4 587. 87 K 1. QM. 7 R 1. 0640 E-04 124. 133 4 531. 25 K 1. QM. 8 R -4. 2431 E-03 -495. 028 4 162. 20 K 1. QT. 1 L -4. 9751 e-03 -580. 428 6 3543. 69 K 1. QT. A 2 L 5. 2595 e-03 613. 668 9 9601. 686 K 1. QT. B 2 L 5. 2595 e-03 613. 668 9 9601. 686 K 1. QT. 3 L -5. 3434 e-03 -623. 369 8 9731. 53 K 1. QM. 4 L 2. 2804 E-04 266. 04 4 3798. 29 Matching section: K 1. QM. 5 L -8. 8592 E-04 -103. 36 4 1506. 53 K 1. QM. 6 L 1. 2144 E-03 141. 68 4 587. 87 D = 60 mm Bpole = 16 T K 1. QM. 7 L -1. 0640 E-04 -124. 133 4 531. 25 K 1. QM. 8 L 4. 2431 E-03 495. 028 4 162. 20 Pre-CDR： R=30 mm 20 mm=20σ σ=1 mm β=σ^2/ε=10. 03 km G=533. 3 T/m K 1=4. 572*10^-3

Separation Dipole • • • L=1070. 8 m β*=0. 75 m RMS bunch length=7. 55 cm Normalize emittance= 4. 0μrad Momentum compaction factor=1. 4*10^-4 …… Full crossing angle=146μrad

Separation Dipole

Summary for part 2 u The first version of SPPC Lattice was designed (Version 1. 0). The whole length and layout is according to CEPC lattice layout. full crossing angle is 146 urad. u Crossing angle and Separation Dipole need to be studied and installation. u LSS 3_pp low-β pp optics need to be studied and optimization. u The Dynamic Aperture need to be studied: MADX or Sixtrack.

Acknowledge • Gang Xu, Qing Qin, Yuan Zhang, Yuemei Peng, Qingjin Xu, Yukai Cui, Xiaohao Cui, Zhe Duan, Yudong Liu, …… • Thanks for your kind help and beneficial discussion!

Reference [1] CEPC-SPPC Preliminary Conceptual Design Report, The CEPC-SPPC Study Group, IHEP-CEPC-DR-2015 -01. [2] J. Gao, IHEP-AC-Note-2013 -012. [3]Xiao Ming et al, CEPC_bunch_train _ 2015 -8 -28 [4]Oridy, FCC-ee_150917 [5] P. Raimondi, Status on Super. B effort, La Thuile, March 11, 2006 [6]W. Kalbreier, et al, “Layout, design and construction of the electrostatic separation system of the LEP e+e- collider”, CERN, Geneva, Switzerland. [7] R. Martin, et al, “Status of the FCC-ee interaction region design”, HF 2014 Workshop, Beijing, China, 9 -12 October, 2014

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