1. Status & operational experience of Liberas at SSRF Leng Yongbin, Yan Yingbing, Zhou Weimin, Chen Yongzhong Ye Kairong, Yuan Renxian, Zou Yi, Yu Luyang, Huang Guoqing BI Group, SSRF 2009-06-22

2. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Outline  Introduction of SSRF  SSRF BPM system  Libera applications Tune monitor Beam spectrum monitor Beam current & charge measurement BPM phase advance monitor

3. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Shanghai Synchrotron Radiation Facility  Third generation light source  Total budget is about 130 millions EURO  Started @ 12/25/2004 and is open to user @ 5/1/2009

4. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 SSRF complex

5. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Libera based BPM system

6. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Specification

7. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 BPM system overview ComponentsSolutionProducer PickupStripline @ injector Button @ ring Customer design, local company Customer design, Kyocera, Japan CableMajor cable, SMR400 Jumper cable, SMR240 Field fabricated, Times microwave Prefabricated, Times microwave ProcessorLibera electronIT IOC softwareDLS packageDiamond Light Source Group accessSoft IOC, EPICS DB chainCustomer design High level application Matlab, LCA Soft IOC analyze packageCustomer design

8. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Ring pickup factory test Mechanical inspection DC isolation resistance Capacitance Magnetic permeability AC voltage break down Network analyzer S11 Leakage BPM block gauge

9. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Ring pickup factory test

10. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 BPM station 5 ID BPM Blue line 30m, redundancy for installation 20m The longest cable should be shorter than 30m + 20m = 50m Total insertion loss < 0.1 * 50 + 0.5 + 0.5 = 6dB Major cable TIMES LMR400 Loss < 10dB/100m Jumper cable TIMES LMR240 Total loss < 0.5dB BPM cabling

11. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 BPM cable & processor installation

12. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 BPM data & functions ready for accelerator physicists Support by DLS package ADC raw data @ 117MHz, 2048 points First turn data synchronized by injection trigger First 2048 samples of TBT data synchronized by injection trigger Up to 0.5M samples of TBT data on demand 10Hz SA data, orbit measurement Embedded position interlock logic User defined current scaling factor (beam current measurement) Instrumentation Technologies delivered 10kHz FA data @ SFP port SSRF added some applications 24 hours buffer for SA data @ EPICS DB level Auto Gain Control logic (1Hz) @ EPICS DB level Beam lifetime measurement @ EPICS DB level Phase advance measurement @ EPICS DB level

13. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Current performance No obvious critical narrow band noise below 100Hz Integrated noise @ [0 1kHz] smaller than 1um Could be improved by identify & remove unknown noise source

14. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Ring BPM resolution 0.2mA 1mA 10mA 200mA COD resolution, BW 2Hz TBT resolution, BW 350kHz COD resolution @ topup operation  COD resolution: typical <200nm, best <80nm, with ideal beam <40nm  TBT resolution: typical 3um  Uniformity of filling pattern is important for BPM performance

15. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Beam current dependency (1) Evaluated during injection (15minutes) BPM readings drift including: electronics BCD&FPD, BPM block drift, orbit drift More than 90% drift within 20um, few BPMs drift up to 70um @ [100mA 200mA] Electronics BCD&FPD only: within 5um @ [100mA 200mA] Reference BPM Normal BPMs

16. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Beam current dependency (2) Evaluated during decay (2.5 hours) BPM readings drift including: electronics BCD&FPD, BPM block drift, orbit drift More than 90% drift within 10um, few BPMs drift up to 30um @ [170mA 200mA] Electronics BCD&FPD only: within 1.5um @ [170mA 200mA] Normal BPMs Reference BPM

17. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Filling pattern dependence (1) 2 4 8 16 32 48

18. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Filling pattern dependence (2) No evidence showed that BPM readings jumped due to filling pattern changing

19. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Filling pattern dependence (3) No evidence showed that BPM readings jumped due to filling pattern changing Original fill refill

20. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Libera application

21. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Tune monitor configuration Configuration is the same for Booster and Ring

22. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Tune monitor performance: Ring Daily operation: FFT of 10k TBT data, uncertainty < E-4 Precise measurement: FFT of 400k TBT data, uncertainty < E-5 Typical TBT data during tune measurement Precise tune measurement Daily operation panel

23. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Tune monitor performance: Booster TBT data 400k samples, cover 240ms FFT windows size 2048, 1/1.23ms = 800Hz Tune measurement uncertainty < E-3 Horizontal ramping tune Vertical ramping tune Tune drift during ramping

24. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Beam spectrum monitor (TBT) Current dependent few tens Hz noise @ copper cavity running. Gone with copper cavity

25. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Beam spectrum monitor (TBT) Observed 15Hz & 46Hz noise, PS group targeted the source based on this information

26. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Beam spectrum monitor (10Hz) 0.1Hz, 3.1Hz and 4.5Hz noise observed, still working to identify the source

27. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Beam current & charge measurement  Libera could be used to measure beam current, data rate usually is better than PCT system. But  Orbit offset adjustment should be applied.  RF frequency adjustment should be applied.  Current scale factor (KI) and current offset should be precisely calibrated with PCT one by one.  It’s easy to do when machine running with fixed orbit. If orbit moving it will be very complicated.

28. BI group SSRF, Feb 2008 Beam arrival monitor Injected beamFirst turn Multi turnsStored beam Sum signal of first turn, calculated from ADC data Bad cable connection, or huge orbit offset

29. SSRF, Feb 2008 Beam current measurement @ ring Current resolution testRF frequency dependence observed Orbit dependence observed Current resolution is better than PCT @ [0 50mA] Current measurement error 0.2% due to RF change Up to 2% current error due to orbit move

30. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 BPM Phase advance monitor The phase difference between two neighboring BPMs can be calculated Cell 1

31. YAN Yingbing / SSRF BI group Libera Workshop, ESRF, Jun 2009 Acknowledgment  Guenther Rehm and Micheal Abbott from DLS  Jean-Claude Denard from Soleil  Jim Sebek and Bob Hettel from SSRL, SLAC