SSRF Beam Diagnostics Commissioning. LENG Yongbin on behalf of SSRF BI group

Transcription

1 SSRF Beam Diagnostics Commissioning LENG Yongbin on behalf of SSRF BI group

2 Outline Instruction of SSRF Overview of SSRF BI system Subsystem Beam position monitor Tune monitor Current & charge monitor Diagnostics beam line Transverse feedback Status of other components Summary

3 Shanghai Synchrotron Radiation Facility

4 SSRF complex

5 Ring Parameters

6 Beam lines in the first stage

7 Construction schedule

8 Time Milestone for BI system 2001 ~ 2004 Preliminary research & design Project start Internal design review Events International design review (Bob, Guenther, JC, Sun Baogen, Cao Jianshe) Linac diagnostics ready in day one for Linac Booster diagnostics ready in day one for Booster BPM, DCCT, TM, parts of SRM ready in day one for Ring Interferometer online Streak camera & gated camera online Transverse feedback online System performance evaluation, targets achieved

9 Primary requirements measurements Ring Booster Linac&TL Beam position 694kHz 10Hz 1.67MHz Tune 1Hz 200Hz Current / Charge 1Hz 10kHz 2% Profile / Size 10um 200um 200um Bunch length 2ps Energy 0.1% Other components Transverse feedback 1 Slit/Scraper 1 3 Fast orbit feedback 1 single pass

10 System design LN LTB BS BTS SR Purpose Stripline BPM Beam position, longitudinal distribution Button BPM 152 Beam position, bunch charge, filling pattern PCT 1 1 Average current, lifetime WCM Bunch charge, longitudinal distribution ICT Bunch charge Faraday Cup 1 Bunch charge Screen Monitor Profile, energy, emmitance for Linac & TL Tune Monitor 1 1 Tune measurement Slit 2 1 Energy purity Scraper 2 Machine study, collimator Diagnostics BL 1 Profile, transverse beam size, bunch length Transverse FB 1 Beam stability Orbit FB 1 Orbit stability Total

11 DAQ Hardware & software platform subsystem Sensors Electronics DAQ/Control Beam position Button/stripline Libera Linux embedded IOC Bunch charge WCM/ICT/FC Oscilloscope Windows embedded IOC Tune Stripline kicker Function generator HTTP access Trans profile Phosphor / OTR CCD PXI IOC+ image grabber Beam current NPCT175 Bergoz PXI IOC + DMM Slit / Scrapper Step motor Motor driver PXI IOC + Motion controller Trans feedback Stripline kicker Spring-8 board PXI IOC + DI/O Filling pattern Button RF front-end PXI IOC + waveform recorder Beam size SRM Interferometer (CCD) PXI IOC + image grabber Beam length SRM Streak camera IPC + image grabber Timing EVR VME (VxWorks) IOC PXI IOC talks to EPICS through Shared Memory IOCcore, which wins due to We had experiences before Easy to learn and use for new players Easy to move from lab test system to field system Easy to modify and debug in the field

12 DAQ System Architecture Central control room Linux OPI Linux OPI Linux SoftIOC EDM panel CA Client Channel Access VME IOC Libera IOC PXI IOC Scope IOC 1 units 3 units 1 units 1 units Linac VME IOC Libera IOC PXI PXI IOC Scope IOC 2 units 38 units 3 units 2 units Booster & tranport lines Control network / EPICS Channel Access CA Server Running DB Record Support Device Support vxworks driver VME HW CA Server Running DB Record Support Device Support CSPI Linux driver Libera HW CA Server Running DB Record Support Device Support Shared Memory SM DLL SM LabVIEW Interface LabVIEW Application LabVIEW Driver PXI HW CA Server Running DB Record Support Device Support VISA Virtual GPIB Scope HW VME IOC Libera IOC PXI PXI IOC Scope IOC 11 units 142 units 4 units 1 units Storage Ring VME IOC Libera IOC PXI IOC scope IOC 13 BI stations + 1 SRM lab, total 212 IOCs Five kinds of IOCs used: VME, Libera, PXI, Scope, Soft

13 Beam Position Monitor Ring Booster Linac & TL Design goals Achievement 10Hz < 10Hz 694kHz < 694kHz 1.67MHz < 1.67MHz SP < SP

14 BPM System Architecture OPI High level application BPM processors Libera Control network / EPICS CA Timg fiber network Timing IOC trigger Digital Digital Digital Digital BPM BPM BPM BPM processor processor processor processor... next station Beam diagnostics station #i 14 units BPM signal feeding network Cable panel Cable tray... ID ID BPM BPM Arc Arc BPM Arc BPM Arc BPM Arc BPM BPM ID ID BPM BPM Arc Arc BPM Arc BPM Arc BPM Arc BPM BPM Shielding wall... 2 IDBPMs & 5 ArcBPMs Cell #17 Cell #18 2 units 5 units 2 units 5 units Cell #2i Cell #2i-1 Storage Ring Cell #4 Cell #3 Pickup assembly Cell #19 Cell #20 Cell #1 Cell #2

15 BPM data & functions Support by Diamond Light Source package ADC raw 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 SFP port SSRF added some applications 24 hours buffer for SA EPICS DB level Auto Gain Control EPICS DB level Beam lifetime EPICS DB level Phase advance EPICS DB level

16 Ring BPM resolution evaluation COD resolution: typical <200nm, best <80nm, with ideal beam <40nm TBT resolution: typical 3um Uniformity of filling pattern is important for BPM performance BPM resolution (μm) SSRF Ring BPMs resolution Average of all 140 BPMs Beam current (ma) COD resolution, BW 2Hz BPM readings STD 10Hz Ring BPM resolution 202mA top-up operation BPM3 10BPM1 10BPM3 14BPM7 16BPM5 10BPM5, electronics evaluaiton setup BPM index COD topup operation TBT resolution, BW 350kHz 30 SSRF Ring 140 BPMs rms noise 0.2mA 12 SSRF Ring 140 BPMs rms noise 0.9mA 14 SSRF Ring 140 BPMs rms noise 10.1mA 16 SSRF Ring 140 BPMs rms noise 199.5mA Counts Counts 8 6 Counts Counts BPM resolution varation (μm) BPM resolution varation (μm) BPM resolution varation (μm) BPM resolution varation (μm) 0.2mA 1mA 10mA 200mA

17 Tune Monitor Ring Booster Design goals Achievement 200Hz 800Hz 1Hz 1Hz

18 Tune monitor configuration Configuration is the same for Booster and Ring

19 Tune monitor performance: Ring Typical TBT data during tune measurement Daily operation panel Daily operation: FFT of 10k TBT data, uncertainty < E-4 Precise tune measurement

20 Tune monitor performance: Booster Horizontal ramping tune Vertical ramping tune Tune drift during ramping TBT data 400k samples, cover 240ms FFT windows size 2048, 1/1.23us = 800Hz Tune measurement uncertainty < E-3

21 Current & Charge measurement Design goals Achievement Ring DCCT 1Hz 1Hz Booster DCCT 10kHz 10kHz 2Hz ICT 2% 2Hz

22 Sensors layout 1 Booster 1 Ring 1 Linac 1 LTB transfer line 1 BTS transfer line Transfer efficiency could be fully evaluated with this configuration BPM + Ring Bunch charge & filling pattern

23 Average current measurement: DCCT Shield design borrowed from SPEAR3 Bergoz NPCT175 NI 4070 DVM NI 8187 PXI controller

24 DCCT readings / I DCCT (ma) Current readings deviation (μa) DCCT performance evaluation SSRF Ring DCCT linearity Measured data Linear fitting I DCCT = I INPUT * A + B A = ± B = ± Calibration current setting / I INPUT (ma) 1 SSRF DCCT resolution real beam current calibrator Input current (ma) Ring Resolution < 1Hz Nonlinearity < 0 ~ 300mA DCCT readings / I DCCT (ma) Current readings deviation (μa) SSRF Booster DCCT linearity Measured data Linear fitting I DCCT = I INPUT * A + B A = ± B = ± Calibration current setting / I INPUT (ma) SSRF Booster DCCT resolution Current calibrator Input current (ma) Booster Resolution < 10kHz, < 2Hz Nonlinearity < 0 ~ 20mA

25 Bunch charge measurement: ICT Scope embedded IOC TEK DPO7054 BW 500MHz 20 ICT raw waveform acquired by scope IOC 0-20 Amplitude (mv) Bergoz ICT Time (ns) Counts ICT resolution Total samples1000 Average = 1.067nC STD = 9pC / = 0.8% ICT readings (nc) 1000 samples RMS: 0.009/1.067nC = 0.8% P-P: 0.06/1.067 = 5%

26 Bunch charge measurement: BPM Storage ring filling Bunch charge (nc) Acquiris DC252, BW 2GHz Sampling rate 8GHz PXI BCM BCM full range = 1nC, readings STD = 0.9pC Bunch ID PXI BCM readings, average = 0.23nC, STD = 0.9pC Bunch ID = 96 Bunch charge (nc) Bunch ID 304 ~ 306, lifetime ~ 14 hours Bunch ID 311 ~ 314, lifetime ~ 18 hours Bunch ID 308 ~ 310, lifetime ~ 21 hours Counts Time (hours) 2000 samples RMS: 0.9pC/1.0nC = 0.1% Bunch charge readings varation (pc)

27 Diagnostics Beam Line Design goals Achievement Beam size 10um 10um Beam length 2ps 2ps

28 Layout #2 BM I the cell #2

29 Diagnostics beam line: bench setup Removable mirror V interferometer From source point 1677cm CCD CCD Horizontal 217 Vertical Gated Camera H interferometer Imaging Streak camera Gated camera 55 Streak Camera Removable mirror 15 CCD Mirror Half mirror Lense Double slit

30 Diagnostics beam line: image system mA, no COD correction copper cavity mA, COD um level copper cavity mA SC cavity, noisy PS mA SC cavity, noisy PS fixed

31 Diagnostics beam line: Interferometer Counts Vertical beamsize = , 202.2mA Beam size readings varation (μm) Counts Horizontal beamsize = , 190.7mA Beam size readings varation (μm) Measured beam size (μm) Horizontal beam size Vertical beam size Beam current (ma) Measurement uncertainty um level, system resolution better than 10um

32 Transverse Feedback Bandwidth System gain Design goals 250Mhz Achievement 250Mhz > 40dB

33 Transverse feedback Stripline injection section, BPM #2 straight section Spring8 designed digital feedback processor In-house made separate stripline kicker in-house made RF front-end Betatron oscillation attenuation > 40dB

34 Transverse feedback performance SSRF multibunch transverse feedback system GeV, SC RF Current = 140mA Vertical beamsize (μm) Feedback ON, δ V = 32±4μm Feedback OFF, δ V = 101±2μm Feedback ON Time (minutes) 10 2 Beam power 3.5GeV, 140mA, MBTF OFF 197.2kHz / Amplitude = 29 X plane Y plane 10 2 Beam power 3.5GeV, 140mA, MBTF ON X plane Y plane PSD (um 2 /Hz) kHz / Amplitude = 2.2E-4 PSD (um 2 /Hz) kHz / Amplitude = 5.8E-4 System gain 29/7E-4 > 40dB Frequency(kHz) Frequency(kHz)

35 Status of the other components Screen monitor is daily operation toolkits for Linac & TL important in day one commissioning for both booster & ring Slit is rarely used now used few times during booster commissioning Scraper is very useful for machine study used as collimator to protect IDs in daily operation WCM is rarely used now good tools for operator in commissioning stage Fast orbit feedback is under commissioning

36 LINAC LTB BTS BS SR Summary (1) Measurement Specification Achievement Beam position Resolution < SP Beam profile Resolution 200μm@2Hz 2Hz Bunch charge Relative accuracy 2% 1% Energy Relative accuracy 0.1% 0.1% Emmitance Relative accuracy 10% 10% Beam position Resolution 100μm@1.67MHz < 50um@1.67MHz Beam profile Resolution 200μm@2Hz 2Hz DC current Resolution 50μA@10kHz 30uA@10kHz 10uA@2Hz Tune Resolution 0.001@200Hz 0.001@800Hz Beam position Resolution 10μm@694kHz 694kHz Resolution 1μm@10Hz 10Hz Beam profile Resolution 10μm 10um Beam length Resolution 2ps 2ps DC current Resolution 10μA@1Hz 1Hz Tune Resolution @1Hz @1Hz MBTF BW 250MHz BW 250MHz, -40dB gain

37 Summary (2) Beam diagnostics meets all physical requirements All necessary diagnostics tools ready in day one for commissioning Adopting new technologies and methods accelerates system development and implementation All design goals achieved except fast orbit feedback Fast orbit feedback could be online this year We need keep working on stability & reliability issues

38 Acknowledgments The development of SSRF beam diagnostics is a successful story of international collaboration. Without comments, suggestions from accelerator community we could not make it. In particularly many thanks to Guenther Rehm and Michael Abbott from Diamond Light Source Bob Hettel, Jim Sebek, James Safranek, Jeff Corbett from SLAC Tadayoshi Misuhashi from KEK Takeshi Nakamura from Sring8 Jean-Claude Denard from Soleil Light Source Hsu Kuo-Tung from Taiwai Light Source Cao Jian-She She and Ma Li from IHEP Sun Bao-Geng Geng from NSRL We hope we can do more contribution to this community in the future.

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