1. Introduction of Accelerators for Circular Colliders 高亮度 TAU-CHARM 工厂 & 先进光源， 2014/09

2. WHAT’S A τ-C FACTORY e+ e- collider working on τ-C energy region 2-5GeV

3. HIGH LUMINOSITY τ-C FACTORY & ADVANCED LIGHT SOURCE Very High Luminosity Design Luminosity 10 35 /(cm 2 ·s) ， 100 times as it is @BEPC II High Performance Light Source Operation time 10 months per year; Emittance nm·rad; Energy 2GeV, VUV-soft X ray

4. Differences between Colliders and Light Sources Different construction goal  different beam quality requirements luminosity ； brightness;  different design and optimize methods

5. Differences between Colliders and Light Sources Specific devices For interaction region of colliders:  final focus facilities, long straight sections, deflectors, superconducting quadrupoles, etc. For light sources:  beam lines, insertion devices(especially for 3 rd generation light sources)

6. Requirements in common Beam quality and stability Beam Physics Colliders ： beam polarization ， beam-beam effect ， electron cloud effect, hourglass effect, local compensation Light source physics ： collective effect driven by impedance, global similar, but also different Differences between Colliders and Light Sources

7. + 同步辐射光源的亮度定义为单位相空间体积内的光子通量 + 对于高斯分布来说，其光谱亮度为 + 亮度常用单位为： 光子数 / （秒 毫米 2 毫弧度 2 0.1 ％带宽） 总光子通量 单位水平角的光 子通量

8. LHC Large Hadron Collider, LHC, CERN, Franco-swiss border near Geneva.Large Hadron Collider, LHC, CERN, Franco-swiss border near Geneva. Particle physics, 2008.9.10 15:30 (GMT+8)Particle physics, 2008.9.10 15:30 (GMT+8) World’s largest collider. Bunch Energy 7tev ， Collision Energy 14tev, Proton colliderWorld’s largest collider. Bunch Energy 7tev ， Collision Energy 14tev, Proton collider

9. LHC LUMINOSITY LUMINOSITY 2011, 4.67 × 10 32 CM − 2 S − 1 NOMINAL, 10 34 ; ULTIMATE, 2.3×10 34 FUTURE PLAN (2020) FACTOR OF 10 ： HL-LHC INTENSITY （ NOMINAL) 4.7×10 14 INTENSITY （ NOMINAL) 4.7×10 14 LHC 隧道，隧道直径三米，贯穿瑞士与法国边境 LHC 示意图

10. PEP II B-factory @ SLAC, 9GeV e- beam HER below, 3.1GeV e+ LER above Peak Luminosity 12.069×10 33, with intensity: LER 2.9A HER 1.875A Lattice Parameters & Bunch size 10

11. PEP II Final focus magnet system for PEP II 11 Wiggler control horizontal beam emittance The magnet system must fit within the particle detector, has no iron, and consists of four nested separately controlled magnets: a two-layer 11.95 T/m quadrupole; a horizontal dipole; a vertical dipole; and a 1.5T solenoid.* A Final-Focus Magnet System For PEP-II Deflector RF cavity (crab cavity)

12. PEP II · Beam Physics Works on improving the luminosity, 2003 ① : correcting the orbits, adding specific orbit bumps, lowering the beta y* in the LER, moving the fractional horizontal tunes, etc. ① Progress of the PEP-II B-Factory, J. Seeman, et al. Improvement based on optics model and beam-beam simulation, 20%, 2006 ② : As a result, the specific luminosity increased nearly 20%. The largest luminosity gain actually came from minimizing nonlinear chromatic effects and running both rings much closer to the half integer resonance in the horizontal plane. ② Luminosity Improvement at PEP-II Based on Optics Model and Beam-Beam Simulation, Y. Cai, et al.

13. PEP II · Beam Physics 13 HER bunch length vs current Reduce momentum compaction factor to achieve a smaller bunch length ③ ③ Lattice with Smaller Momentum Compaction Factor for PEP-II High Energy Ring, Y.Cai et al. Lowering the vertical emittance and improve the luminosity ④ ④ Lowering The Vertical Emittance in the LER Ring of PEP-II, F.-J. Decker et al.

14. PEP II · Beam Physics 14 Other study, i.e. electron-cloud effect at the PEP-II positron ring ⑤ simulation results for the emittance blowup due to the head-tail effect induced by the electron-cloud effect (ECE) in the low-energy ring (LER) at the PEP-II B factory at SLAC. ⑤ New simulation results for the electron-cloud effect at the PEP-II positron ring, Y.Cai et al. 2001

15. KEKB B-factory @ Tsukuba, Ibaraki, Japan Belle Experiment 8 GeV e-HER 1.1A, 3.5GeV e+LER 2.6A Similar to PEP II Peak Luminosity 2.11×10 34 （ 2009/06) Superconducting final-focus quadrupole Emittance x:18nmrad y: 0.36nmrad 15 1995, KEKB STATUS AND PLANS, Shin-ichi Kurokawa

16. KEKB beam physics and upgrade Finite-Angle Crossing of Beams PEPII: head-on collision Superconducting crab cavities for unpredictable beam-beam effects due to this finite-angle crossing——crab-crossing Study of the Beam-beam Effect for Crab Crossing IN KEKB and SUPER KEKB, K. Ohmi, et al., PAC05; crab cavity, installed in 2007 SuperKEKB original plan: in order to achieve 20 times higher luminosity KEKB and SuperKEKB, H. Koiso, et al., APAC 2004; smaller betay, larger vertical beam-beam parameter and higher current SuperKEKB: 8×10 35, a super B factory, nano-beam, crab-waist collision Super KEKB and Belle II: Status of the KEK Super B Factory, 2009

17. KEKB beam physics and upgrade Large Piwinski angle + Crab waist

18. Super B factory A high luminosity (over 10 36 ） asymmetric e+e- collider novel combination of LC and storage ring techniques attempts date to 2001, while approaches at old B factories requires very high wall plug power, i.e. 100 MW *super B factory conceptual design report, March, 2007 ** Super B Factory Using Low Emittance Storage Rings and Large Crossing Angle, Y. Cai, J. Seeman et al., PAC 2007 Approved in Jan 2011 http://physicsworld.com/cws/article/news/2011/jan/06/italy-approves-superb-particle- collider Cancelled in Nov 2012 while study results used in its major competitor Super KEKB project http://physicsworld.com/cws/article/news/2012/nov/28/italy-cancels-euro-1bn-superb- collider

19. Large Crossing Angle and Crabbed waist collision scheme High luminosity requires very short bunches to allow decreased betay at the IP Hourglass effect; beam-beam effect Large Piwinski angle and Crabbed waist scheme Large Piwinski angle collision: *Super B factory conceptual design report, March, 2007

20. Super B factory lattice Very small emittance Asymmetric energies Insertion of a final focus with very small Good dynamic aperture and lifetime Allows low emittance storage ring=> 3 rd generation light source Breakthrough in collider design, impact even on the current generation of colliders

21. BEPC II Symmetric τ-C factory built and run by IHEP Energy 1.89GeV, luminosity 7×10 32 (2013) Now highest τ-C Synchrotron mode, 2.5GeV, 250mA 21

22. BEPC uprade to BEPC II Higher current (lower bunch current, much more bunches) Micro-β @ IR: 5.5cm->1.5cm Short bunch: 5cm->1.5cm Insert section: Superconducting magnets 22

23. HIGH LUMINOSITY τ-C FACTORY & ADVANCED LIGHT SOURCE Very High Luminosity Design Luminosity 10 35 /(cm 2 ·s) ， 100 times as it is @BEPC II High Performance Light Source Operation time 10 months per year; Emittance nm·rad; Energy 2GeV, VUV-soft X ray

24. Problems to be answered Is it possible to get high luminosity? Symmetric circular collider as BEPC II, novel combination of LC and storage ring techniques as Super B factories Is it possible to make a brilliant synchrotron too? We use low emittance storage ring, but is it possible to be an excellent light source at the same time? Is it stable? How? 24

25. Works to be done Symmetric circular collider as BEPC II, novel combination of LC and storage ring techniques as Super B factories Usage of long straight section, FELs Series of computer simulation methods, softwares Electron cloud effect Beam-beam effect etc. 25

26. Plans Investigation Conceptual design Apply for several funds from NSFC, etc. Built, run, upgrade and new projects 26