Progress of BEPCII Storage Ring Construction

1. Progress of BEPCII Storage Ring Construction Ma Li May 10, 2007

2. Design goal of BEPCII The BEPCII serves the purposes of both high energy physics experiments and synchrotron radiation applications.

3. Main Parameters of BEPCII

4. N Layout of BEPCII SC cavities SC IR magnets BESIII e+ inj. point e- inj. point

5. Goal and schedule of ring in 2006/2007 • Goal of 2006 • Complete the installation of all equipments (except superconducting IR magnets) • Try to start the SR user operation • Schedule plan achieved 2006/03/02 start installation of storage ring 2006/10/10 2006/11/12 start outer ring commissioning (backup scheme) 2006/11/09 2006/11/25 start SR beam line commissioning and user operation 2006/12/29 2007/02/06 start commissioning e- ring 2007/01/26 2007/03/03 start commissioning e+ ring 2007/03/25 first beam collision (backup scheme) 2007/06/15 start SR user operation (backup scheme) 2007/02/23 2007/08/01 SCQs move into the IR (about 5-month delay) 2007/04/01 start commissioning e- ring with SCQ 2007/04/21 start commissioning e+ ring with SCQ 2007/05/11 start commissioning for collision mode

6. Main tasks of the ring systems Magnet 300-plus dipoles, quads, sextupols, correctors Vacuum 200-plus chambers, 175 photon absorbers, 150 bellows … Align & Install 84 pre-assembly magnet rafts, survey and align, install … RF 2 SC cavities and PS, LLRF IR 2 SC IR magnets, 10 special magnets, IR chamber … AP lattice design, high-level software, beam instability study … PS 300-plus PS, magnet coil temperature monitor … Injection 4 injection kickers and PS Control PSC/PSI, network, timing, database, software develop … Instrumentation 138 BPM, DCCT, BCM, BLM, tune meter, TBF … Pay more attention to critical paths

7. 2006/02/end Complete all 80 arc chambers, including correction of 20 distorted chambers. 2006/03/02 Start installation of the first magnet raft in the ring tunnel. Only 31 of 84 rafts (37%) had been completed at the time. According to schedule, 2 rafts have to be completed in 5 days. No weekend and holidays. 2006/07/18 Start PS test and combined commissioning with magnets and control, in parallel with installation. 2006/08/21 Complete TiN coating of 70 positron beam pipes 2006/09/10 Complete installation of last magnet raft in the ring tunnel 2006/10/29 Complete installation of all chambers and vacuum components 2006/11/09 Complete fine alignment of the ring magnets 2006/11/12 Startring commissioning Critical path 1: Pre-assembly and installation

8. Pre-assembly and pre-alignment

9. Alignment in the tunnel

10. Installation of vacuum components

12. Installation of magnet rafts

13. 2006/03/26 East SC cavity assembly completed 2006/04/28 West SC cavity assembly completed 2006/06/30 Q0 of east SC cavity reached to 5.5×108 @2MV (design goal is 5×108) 2006/07/31 East SC cavity positioned and aligned in the ring tunnel 2006/08/26 Q0 of west SC cavity reached to 9.9×108 @2MV 2006/09/07 West SC cavity positioned and aligned in the ring tunnel 2006/10/29 East SC cavity conditioned to 1.5MV, in parallel with installation 2006/10/31 West SC cavity conditioned to 1.5MV, in parallel with installation 2006/11/04 Commissioning of east SC RF system completed and ready for beam 2006/11/12 Startring commissioning 2007/02/26 West SC cavity put into operation with beam S.Kurokawa, K.Hosoyama, T.Furuya, K.Akai, S.Mitsunobu of KEK came here many times during test and commissioning of SC cavities. Thanks a lot. Critical path 2: superconducting RF system

14. Assembly and tunnel installation of superconducting cavity

15. LLRF installation and commissioning

16. Horizontal high power test of east superconducting cavity

17. 2006/06/21 Q1a, Q1b, ISPB, Q2, Q3 passed acceptance test 2006/08/18 Two superconducting IR magnets cooled-down 2006/08/end Two superconducting IR magnets and PS, quench protection system tested. The magnets are powered with 20-50% rated current. PS and quench protection system showed a good performance. Valve-box and current leads have to be modified. 2-Q and 1-B backup scheme was proposed to replace 2-B scheme. 2006/09/29 Two superconducting IR magnets moved out off the ring 2006/10/begin BPM welding on the OFHC IR chambers had some troubles. Decide to fabricate substitutions of stainless steel chambers for OFHC chambers. 2006/10/26 Complete fabrication of stainless steel IR chambers 2006/10/29 Complete installation of IR chambers and vacuum pumps 2006/11/05 Complete cable connections and chamber baking 2006/11/10 Complete combined commissioning of IR magnets, PS and control systems 2006/11/12 Startring commissioning Critical path 3: IR magnets and chambers

18. Installation superconducting IR magnets and valve-box

19. Horizontal test of superconducting IR magnets

20. With this 2-dipole backup scheme, the collision mode cannot be commissioned. Backup scheme with 2 dipoles (April, 2006)

21. BEPC magnet supports are used to saving time and cost Change scheme with 2 quads and 1 dipole (September, 2006)

22. Installation of IR components

23. Systems not on the critical path AP lattice design, high-level software, beam instability study … Power Supply 300-plus PS, magnet coil temperature monitor … Injection 4 injection kickers and PS Control PSC/PSI, network, timing, database, software develop … Instrumentation 138 BPM, DCCT, BCM, BLM, tune meter, TBF … All efforts have been made toprevent these systems from becoming a new critical path.

24. impedance measurement solenoid for suppressing ECI

25. Commissioning and test of the magnet PS

26. Injection kickers and PS

27. Installation and commissioning of PS control system

28. Center control room

29. BPM

30. Synchrotron light monitor

31. Transverse beam feedback system

32. 开机后发现仍然有差错 • 内、外环电源搞错 • 磁铁极性接反 • 部分磁铁线包有短路 • 经验：不同人员反复检查 Step-by-step inspection performed before the commissioning

33. 2006/09/22 First meeting of the Ring Commissioning Group led by Jiuqing Wang 2006/11/12 Start ring commissioning 2006/11/18 First e- beam storage in outer ring (SR ring) 2006/12/25 Start SR user operation 2007/02/02 Stop SR user operation 2007/02/09 First beam storage in e- ring 2007/02/18 Spring Festival (7-day holiday) 2007/03/04 First beam storage in e+ ring 2007/03/25 First trial of beam collision at 6mA×6mA 2007/04/10 150mA e+ beam current reached 2007/04/21 100mA e- beam current reached Jiuqing will give detailed descriptions for the ring commissioning. Milestone of ring commissioning

34. 2007/1/2, 2007/4/26 and 2007/5/9, three primary windings of 10kV rectifier transformer of ring main dipole magnet PS had broke down, respectively. There are 8 transformers, with 3 such windings each. It is quality problem. 2007/1/6, compressor of cryogenic system shut down due to power line failure, causing superconducting RF cavity warmed up to 40K. It was recovered 26 hours after. 2007/1/7, compressor of cryogenic system shut down due to water-cooling problem. It was recovered 20 hours after. 2007/2/11, cryogenic system failure, causing superconducting RF cavity warm up to 20K. It was recovered 17 hours after. 2007/2/13, compressor of cryogenic system shut down due to a misoperation. It was recovered 8 hours after. 2007/1/30, a quench happened during conditioning of east cavity. Pressure in cryostat up to 1.26bara threshold due to quench protection system was not functioned in 10ms, causing the safety valve opened. It was recovered 21 hours after. During commissioning, RF trip frequently occurred by vacuum, arc, quench, klystron pump PS, and sometimes noise, 2-3 times per day on average. Sometimes beam loss happened during the energy ramping from 1.89GeV to 2.5GeV. Equipment failures and problems

35. Main tasks of ring in 2007 • Hardware • IR chambers (3 types of SCQ, Y-shape and ISPB chambers) • Superconducting IR magnets (high power test, field measurement, installation) • 14 fixed and 2 movable masks • Commissioning and operation • Collision mode (backup scheme) • One-month SR operation, beam lifetime 8-10 hours @150mA/2.5GeV • Collision mode with superconducting IR magnets

36. Schedule of IR 2007/04/30-2007/05/10 SCQ and SSM cool-down 2007/05/11-2007/06/03 cryogenic system commissioning and SCQ high power test 2007/06/04-2007/07/31 SCQ field measurement with SSM 2007/08/01-2007/08/22 move SCQ into IR 2007/08/23-2007/09/21 SCQ field measurement in IR without detector 2007/09/22-2007/10/10 install IR components 2007/10/11-2008/02/09 commissioning (4 months) 2008/02/10-2008/03/20 SR user operation 2008/03/21-2008/05/07 move BESIII detector into IR 2008/05/08-2008/06/22 BESIII tuning 2008/06/23-2008/12/31 BESIII physics operation

37. Modification of SC IR magnet valve-box and current leads

38. Superconducting IR magnets are ready for field measurement

39. ISPB chamber SCQ chamber Y-shape

40. Open questions • When is the suitable time for installation of background masks? • The east superconducting cavity shows a different performance during commissioning of e- ring. What is the reason? • Whether the phase-lock loop between master oscillators of the injector linac and the rings is necessary?

41. Summary • A big progress for the construction and commissioning of the BEPCII storage rings has been made since last IMAC meeting. • It took about 16 months to complete the installation of BEPCII rings (except the superconducting IR magnets and IR chambers) after the BEPC ring shut-down in July 4, 2005. • Commissioning of the BEPCII (with backup scheme) started in mid November 2006. It is useful for us to gain experience for the future commissioning with superconducting IR magnets. • Although there are some problems, basic equipments and devices of ring systems show a good performance during the half-year commissioning and operation. • The final test of the superconducting IR magnets with modified valve-box and current leads is in progress. Success of the test is very important to reach the goal of the BEPCII project in time.

42. Thank you for attentions !