CEPC/SppC with ILC ( FCC)

J. Gao

Institute of High Energy PhysicsBeijing, CAS

Panel discussion, Nov. 5, at LCWS 2015Nov. 2-6, 2015, Whistler, Canada

http://cepc.ihep.ac.cn/

Important remindsCEPC-SppC is proposed in Sept. 2012, right after Higss discovery at CERN by LHC in July 2012

“C” in CEPC doesn’t stands for China, but “Circular” and mostly for high energy physics “Community”. CEPC is of the Community, by the Community and for the Community

ILC, CEPC, FCC(ee) are proposed tools to produce Higgs (+ others) through e+e- collision

ILC, CEPC, FCC(ee) have many common technologies and task force overlapes

The succeed of the community is the succeed of any of them

In Oct. 30, 2015, Chinese government cleared next five year plan and beyond on science with the following statement: “Actively propose and lead the international science plans and big scientific projects ( 积极提出并牵头组织国际大科学计划和大科学工程 ) ”

Ways towards future HEP

1 ） Linear colliders： ILC-CLIC from Higgs energy to 5TeV

(Support and Participation)

2 ） Circular Colliders： CEPC-SppC e+e- Higgs factory-pp collider at 50~100TeV (Host)

Precision @ e+e- colliderEnergy frontier @ pp collider

Higher precision Higher energy

e+ e- LTBCEPC (50km-100km)

Boostr(50Km-100km)

SppC (50-100Km)

4

Introduction to CEPC+SppC(Pre-CDR)

LTB : Linac to Booster

BTC : Booster to Collider Ring

BTC

IP1

IP3

e+ e-

e+ e- Linac (240m)

LTB

CEPC Collider Ring(54Km)

Booster(54Km)

BTCMedium Energy Booster(4.5Km)

Low Energy Booster(0.4Km)

IP4 IP2

SppC Collider Ring(54Km)

Proton Linac(100m)

High Energy Booster(7.2Km)

CEPC/SppC on Site (Example)

CEPC Design – Top Level Parameters

6

Parameter Design Goal

Particles e+, e-

Center of mass energy 240 GeV

Integrated luminosity (per IP per year) 250 fb-1

No. of IPs 2

SPPC Design – Top Level Parameters

Parameter Design Goal

Particles p, p

Center of mass energy 70 TeV

Integrated luminosity (per IP per year) (TBD)

No. of IPs 2

one million Higgs from 2 IPs in 10 years

Z, W, tt (100km) are not optimization goal as that of Higgs!, but with considerations

Parameter Unit Value Parameter Unit Value

Beam energy [E] GeV 120 Circumference [C] m 54420

Number of IP[NIP] 　 2 SR loss/turn [U0] GeV 3.11

Bunch number/beam[nB] 　 50 Bunch population [Ne] 　 3.71E+11

SR power/beam [P] MW 51.7 Beam current [I] mA 16.6

Bending radius [] m 6094 momentum compaction factor [p] 　 3.39E-05

Revolution period [T0] s 1.82E-04 Revolution frequency [f0] Hz 5508.87

emittance (x/y) nm 6.12/0.018 IP(x/y) mm 800/1.2

Transverse size (x/y) m 69.97/0.15 x,y/IP 　 0.116/0.082

Beam length SR [s.SR] mm 2.17 Beam length total [s.tot] mm 2.53

Lifetime due to Beamstrahlung min 80lifetime due to radiative Bhabha scattering [L]

min 52

RF voltage [Vrf] GV 6.87 RF frequency [frf] MHz 650

Harmonic number [h] 　 117900 Synchrotron oscillation tune [s] 　 0.18

Energy acceptance RF [h] % 5.98 Damping partition number [J] 　 2

Energy spread SR [.SR] % 0.13 Energy spread BS [.BS] % 0.08

Energy spread total [.tot] % 0.16 n 　 0.23

Transverse damping time [nx] turns 78 Longitudinal damping time [n] turns 39

Hourglass factor Fh 0.692 Luminosity /IP[L] cm-2s-1 2.01E+34

Main parameters for CEPC (Goal of CDR)

Parameter Value Unit

Circumference 52 km

Beam energy 35 TeV

Dipole field 20 T

Injection energy 2.1 TeV

Number of IPs 2 (4)

Peak luminosity per IP 1.2E+35 cm-2s-1

Beta function at collision 0.75 m

Circulating beam current 1.0 A

Max beam-beam tune shift per IP 0.006

Bunch separation 25 ns

Bunch population 2.0E+11

SR heat load @arc dipole (per aperture) 56 W/m

SppC main parameters (Goal of CDR)

258 authors from 45 institutions

in 9 countries

1 Institute of High Energy Physics, China (高能物理研究所) 2 Institute of Modern Physics, China (近代物理研究所)

3 Shanghai Institute of Applied Physics, China (上海应用物理研究所) 4 Peking University, China (北京大学)

5 Tsinghua University, China (清华大学) 6 University of Science and Technology of China (中国科技大学)

7 Shanghai Jiao Tong University (上海交通大学) 8 Yellow River Engineering Consulting Co., Ltd., China (黄河勘测规划设计有限公司) 9 Innova Superconductor Technology Co., Ltd., China (北京英纳超导技术有限公司)

10 Western Superconductor Technologies Co., Ltd., China (西部超导材料科技股份有限公司) 11 Shanghai Superconductor Technology Co., Ltd., China (上海超导科技股份有限公司)

12 Northwest Institute for Non-ferrous Metal Research, China (西北有色金属研究院) 13 Northwestern University, U.S.A.

14 Brookhaven National Laboratory, U.S.A. 15 SLAC National Accelerator Laboratory, U.S.A.

16 Fermi National Accelerator Laboratory, U.S.A. 17 Lawrence Berkeley National Laboratory, U.S.A.

18 Thomas Jefferson National Accelerator Facility, U.S.A. 19 Cornell University, U.S.A.

20 Budker Institute of Nuclear Physics, Russia 21 High Energy Accelerator Research Organization (KEK), Japan

22 University of Milano and INFN Milano - LASA, Italy 23 University of Chicago, U.S.A. 24 University of Arizona, U.S.A.

25 University of Pittsburgh, U.S.A. 26 Duke University, U.S.A.

27 University of Massachusetts, U.S.A. International review has been done in the beginning of 2015

http://cepc.ihep.ac.cn/preCDR/volume.html

To better know the potential performance of CEPC/SppC with respect to machine length (50,70,100km),

Collding energies (W, Z, H, tt),

Layout(single ring, double rings, partial double rings), colliding angles (head-on, crab-waist), etc.

Polarized colliding beams

...

More on CEPC parameters and potentials

Parameters Z-pole W-poleE[GeV] 45.5 80

C[km] 50NIP 2

P[MW] 0.89 1.85 4.06 10 12.5 20.8 45.8U0[GeV] 0.62 0.59

I[mA] 14.22 29.6 65.2 16.8 21 35 77Nb 48 100 220 48 60 100 220

Ne[1011] 3.09 3.65ϵx[nm·rad] 48 18.68ϵy[pm·rad] 96 36

βx[m] 0.8 0.8βy[mm] 1.2 1.2σx[µm] 196 122.25σy[µm] 0.34 0.208

ξx 0.032 0.056ξy 0.028 0.049

σs[mm] 2.65 2.65

hourglass factor 0.68 0.68

L[1034cm−2s−1] 0.224 0.466 1.025 0.82 1.02 1.7 3.74

Parameters Higgs FactoryBeam energy E[GeV] 120Circumference C[km] 50 70 100Number of IP NIP 2Bending radius ρ[km] 6.094 8.6 11SR power/beam P[MW] 50SR loss/turn U0[GeV] 3.01 2.13 1.67Beam current I[mA] 16.6 23.4 30.3Bunch number Nb 48 114 220Bunch population Ne[1011 ] 3.61 3 2.87Horizontal emittance ϵx[nm·rad] 6.12 6.36 6.8Vertical emittance ϵy[pm·rad] 21.2 20 18.2Betatron function at IP-vertical βy[mm] 1.2 1.2 1Betatron function at IP-horizontal βx[m] 0.8 0.8 0.8Transverse beam size σx[µm] 70 71.3 73.8Transverse beam size σy[µm] 0.16 0.155 0.135Beam-beam parameter ξx 0.112 0.09 0.08Beam-beam parameter ξy 0.074 0.062 0.055Bunch length σs[mm] 2.65 2.65 2.65Hourglass factor 0.68 0.68 0.63Luminosity L[1034cm−2s−1] 1.82 2.15 2.75

Possible scheme to produce polarized positrons (W. Gai)

To store and collide the injected polarized beams in CEPC are not so obvious

15

Parameter choice for SPPC (Potential)

……

(F. Su et al)

Parameter choice for SPPC (Potential)(F. Su et al)

CEPC Pretzel Scheme

• 48 bunches / beam, 96 parasitic collision points (~ 500 m spacing)• Horizontal separation, no off-center orbit in RF section• One pair of electrostatic separators for each arc (green)• One pair of electrostatic separators for P2, P3, P4, P6, P7, P8

H.P. Geng

CEPC local double ring scheme has been Proposed at IHEP and CERN independently ：

1） J. Gao in June 2013 (IHEP-AC-LC Note 2013-012)

2 ） M. Moratzinos and F. Zimmermann ， IPAC, 2015

CEPC local double two ring scheme has two fold reasons:

1)Introducing large crossing angle to explore crab-waist collision aiming to reduce beam and AC power (J. Gao)

2)Avoiding using prezel scheme to increase the flexibility and increasing Z, W pole luminosities with more bunches (M. Moratzinos and 3)F. Zimmermann)

No pretzel schemeCrab waist possibleCost less than whole double ringsMore bunches for high luminosity Z, WReduced AC power

F.Su, D. Wang et al

Main Technical Challenges for CEPC

1. Lattice design with dynamic aperture for off-momentum up to 2%

2. Pretzel orbit (single beam pipe)

3. Local double ring scheme

4. Low energy injection (6 GeV) to the Booster (low field and DA)

5. Machine-detector interface (L* = 1.5 m)

6. 650MHz CW SCRF accelerating system (high efficiency) with HOM damper for the RF cavity• High average beam current: 2 x 16.6 mA• High HOM loss: 2 x 2.3 kW per cavity

7. Total AC power

8. Advannced detector R&D which is very challenging

CEPC-SPPC Timeline (preliminary)

23CEPC-SPPC Meeting, May 17-18, 2015W. Chou

R&DEngineering Design

(2016-2020)

Construction(2021-2027)

Data taking(2028-2035)

Pre-studies(2013-2015)

1st Milestone: Pre-CDR (by the end of 2014) → R&D funding request to Chinese government in 2015 (China’s 13th Five-Year Plan 2016-2020)

CEPC

R&D(2014-2030)

Engineering Design(2030-2035)

Construction(2035-2042)

Data taking(2042-2055)

SPPC

2nd Milestone: 13th Five year Plan R&D

End of 2016 CEPC CDR should be completed

M. Benedikt

M. Benedikt

M. Benedikt

M. Benedikt

International efforts

CEPC-SppC pre-CDR international review have been done in the beginning of 2015

CEPC-SppC International Advisory Committee has been established and the first meeting was held in Sept. 2015 at IHEP

Start with International working groups

Establishing CEPC international collaboration common task forces

More Synergy with LCC (ILC, CLIC)

More synergy with FCC (ee, pp)

...

CEPC is a chanlleging machine in terms of design, construction and operation for the high energy comminity of the world

Thank you for your attention!

Backup slidesAnalytical formulation of parameter choice or designs

for e+e- and Proton-Proton circular colliders(CEPC-SPPC applications)

References:1) CEPC-SppC Pre-CDR, http://cepc.ihep.ac.cn/preCDR/volume.html

2) J . Gao, "Review of some important beam physics issuesin electron positron collider designs", Modern Physics Letters AVol. 30, No. 11 (2015) 1530006 (20 pages

2) D. Wang, J, Gao, et al, "Optimization parameter design of a circular e+eHiggs factory",Chinese Physics C Vol. 37, No. 9 (2013) 097003

3)M. Xiao, J. Gao, et al, "Study on CEPC performances with different collisionenergies and geometric layouts",IHEP-AC-LC-Note2015-002.

4) F. Su, J. Gao, et al, "Method Study of Parameter Choice for a Circular Proton-ProtonCollider", Chinese Physics C (2015)

Luminosity from colliding beams• For equally intense Gaussian beams

• Expressing luminosity in terms of our usual beam parameters

RN

fLy

b

x

2

4

Geometrical factor: - crossing angle - hourglass effect

Particles in a bunch

Transverse beam size (RMS)

Collision frequency

31

where

max

2845

6p

IP

r

f x RN

dtt

xfx

0

2

)2

exp(2

21)(

IPpIP NrRxf

Nxf

x

6

2845)(4)(4 2

max

2

For lepton collider:

For hadron collider:

J. Gao, “Review of some important beam physics

Issues in electron positron collider designs”,

Modern Physics Letters A, Vol. 30, No. 11 (2015)

1530006 (20 pages)

IPRNer

61

2845maxy,

re is electron radiusγ is normalized energyR is the dipole bending radiusNIP is number of interaction points

rp is proton radius

max,2

maxx, y J. Gao, Nuclear Instruments and Methods in Physics

Research A 533 (2004) 270–274

J. Gao, Nuclear Instruments and Methods in Physics Research A 463 (2001) 50–61

where

IPy N 0T2

2845maxy, π

Maximum Beam-beam tune shift analytical expressions for lepton and hadron circular colliders

Parameters(M. Xiao, et al)

50km CEPC design

Single ring scheme Double ring scheme

Z W H Z W H

Beam energy E[GeV] 45.5 80 120 45.5 80 120

Circumference C[km] 50 50 50 50 50 50

Number of IP NIP2 2 2 2 2 2

Bending radius ρ[km] 6.094 6.094 6.094 6.094 6.094 6.094

SR power/beam P[MW] 0.89 10 50 50 50 50

SR loss/turn U0[GeV] 0.062 0.6 3.01 0.062 0.6 3.01

Ring’s Energy acceptance η 0.02 0.02 0.02 0.02 0.02 0.02

Magnetic rigidity Bρ[T·m] 151.8 266.9 400.4 151.8 266.9 400.4

Momentum compaction factor αp[10−5]2.613 1.556 1.411 2.613 1.556 1.411

Lifetime due to radiative Bhabha scattering τL[hour]

8.26 2.67 1.19 8.26 2.67 1.19

Beam current I[mA] 14.23 16.8 16.6 796.8 84.03 16.62

Bunch number Nb48 48 48 2688 240 48

Bunch population Ne[1011] 3.09 3.65 3.61 3.09 3.65 3.61

ϵx[nm·rad] 48 18.68 6.12 48 20 6.9

ϵy[pm·rad] 96 36 21.2 96 36 21.2

βx[m] 0.8 0.8 0.8 0.8 0.8 0.8

βy[mm] 1.2 1.2 1.2 1.2 1.2 1.2

σx[µm] 196 122.2 70 196 122.2 70

σy[µm] 0.339 0.208 0.159 0.339 0.208 0.159

Bunch length σs[mm] 2.65 2.65 2.65 2.65 2.65 2.65

Beam-beam parameter ξx 0.032 0.056 0.112 0.032 0.056 0.112

Beam-beam parameter ξy 0.028 0.049 0.074 0.028 0.049 0.074

Hourglass factor Fh 0.68 0.68 0.68 0.68 0.68 0.68

Luminosity per IP L[1034cm−2s−1] 0.22 0.82 1.82 12.5 4.08 1.82RF voltage Vrf[GV] 0.167 0.778 3.38 0.167 0.778 3.38RF frequency frf[GHz] 0.65 0.65 0.65 0.65 0.65 0.65Synchrotron tune Qs 0.017 0.127 0.091 0.017 0.127 0.09Energy spread σδ,SR[%] 0.05 0.09 0.13 0.05 0.09 0.13

Average number of photons emitted per electron during the collision nγ

0.064 0.122 0.211 0.064 0.122 0.211

Parameters( M. Xiao et al)

100km CEPC designSingle ring scheme Double ring scheme

Z W H tt Z W H tt

Beam energy E[GeV] 45.5 80 120 175 45.5 80 120 175Circumference C[km] 100 100 100 100 100 100 100 100Number of IP NIP 2 2 2 2 2 2 2 2

Bending radius ρ[km] 11 11 11 11 11 11 11 11SR power/beam P[MW] 0.615 8.35 50 50 50 50 50 50SR loss/turn U0[GeV] 0.034 0.330 1.668 7.546 0.034 0.330 1.668 7.546Ring’s Energy acceptance η

0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02

Magnetic rigidity Bρ[T·m]151.8 266.9 400.4 584 151.8 266.9 400.4 584

Momentum compaction factor αp[10−5]

5.762 1.233 1.009 0.938 5.762 1.233 1.009 0.938

Lifetime due to radiative Bhabha scattering τL[hour]

18.55 5.99 2.66 1.25 18.55 5.99 2.66 1.25

Beam current I[mA] 17.94 25.12 30.29 6.63 1451.5 153.0 30.29 6.63Bunch number Nb 192 192 192 48 15600 1152 192 48

Bunch population Ne[1011]

1.7 2.38 2.87 2.56 1.7 2.38 2.87 2.56

ϵx[nm·rad] 33 18 6.8 3.5 33 18 6.8 3.5

ϵy[pm·rad] 64 24 18.2 6.2 64 24 18.2 6.2

βx[m] 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8

βy[mm] 1 1 1 1 1 1 1 1

σx[µm] 162.4 120 73.76 52.92 162.4 120 73.76 52.92

σy[µm] 0.253 0.155 0.135 0.079 0.253 0.155 0.135 0.079

Bunch length σs[mm] 2.55 2.65 2.65 2.65 2.55 2.65 2.65 2.65

Beam-beam parameter ξx 0.026 0.038 0.08 0.096 0.026 0.038 0.08 0.096

Beam-beam parameter ξy 0.021 0.037 0.055 0.08 0.021 0.037 0.055 0.08

Hourglass factor Fh 0.642 0.632 0.632 0.632 0.642 0.632 0.632 0.632

Luminosity per IP L[1034cm−2s−1]

0.24 1.01 2.75 1.28 19.2 6.15 2.75 1.28

RF voltage Vrf[GV] 0.41 0.55 2.064 8.32 0.41 0.55 2.064 8.32RF frequency frf[GHz] 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65

Synchrotron tune Qs 0.134 0.048 0.059 0.081 0.134 0.048 0.059 0.081Energy spread σδ,SR[%] 0.037 0.065 0.098 0.142 0.037 0.065 0.098 0.142

Average number of photons emitted per electron during the collision nγ

0.043 0.081 0.160 0.200 0.043 0.081 0.160 0.200

Parameters Higgs FactoryBeam energy E[GeV] 120Circumference C[km] 50 70 100Number of IP NIP 2Bending radius ρ[km] 6.094 8.6 11SR power/beam P[MW] 50SR loss/turn U0[GeV] 3.01 2.13 1.67Beam current I[mA] 16.6 23.4 30.3Bunch number Nb 48 114 220Bunch population Ne[1011 ] 3.61 3 2.87Horizontal emittance ϵx[nm·rad] 6.12 6.36 6.8Vertical emittance ϵy[pm·rad] 21.2 20 18.2Betatron function at IP-vertical βy[mm] 1.2 1.2 1Betatron function at IP-horizontal βx[m] 0.8 0.8 0.8Transverse beam size σx[µm] 70 71.3 73.8Transverse beam size σy[µm] 0.16 0.155 0.135Beam-beam parameter ξx 0.112 0.09 0.08Beam-beam parameter ξy 0.074 0.062 0.055Bunch length σs[mm] 2.65 2.65 2.65Hourglass factor 0.68 0.68 0.63Luminosity L[1034cm−2s−1] 1.82 2.15 2.75

39

Parameter choice for SPPC (Potential)

……

(F. Su et al)

Parameter choice for SPPC (Potential)(F. Su et al)