Event timing system for BEPCII storage ring commissioning

1. Event timing system for BEPCII storage ring commissioning Presented by G. Lei May 2007 BEPCII Timing System Status

2. Brief review: by IMAC 2006 • Event timing system had been installed in Linac of BEPCII, Provide trigs to • e-gun, solid state amplifier, PSK, gun power supply, positron source, 16 modulators • Hardware developed • 18 sets of optical transimitting/receiving boards, for gun power supply, positron source, and 16 modulators • Gun-Rx module modified to generate NIM outputs directly • Software developed, • IOC database and OPI for linac timing operating, including BI • Applications to record arriving time of trigs in order to analyze the missed trigs • Functions added to drivers to set EVG/EVR registers to work at 499.8MHz/4, /5, /10 BEPCII Timing System Status

3. Progress in 2006, May to Sept. • We have setup test environment and measured the phase shift of the timing optical fiber cables due to temperature changing. • High temperature in summer was a challenge to timing modules. • By the suggestion of KEKB experts, the 10MHz time-base synchronizing cable was setup between Linac 2856MHz signal generator and ring 499.8MHz signal generator, by Linac microwave group, RF group and us. • Timing main station has been moved from Linac to storage ring central room in Aug. 2006: commissioning the whole timimg hardware and software. The main station has been running since Sept. 2006, stably, and never been rebooted. BEPCII Timing System Status

4. BEPCIItiming system layoutBlue lines: event system optical cablesRed lines: 499.8MHz signalsGreen line: 10MHz time base synchronized with Linac 2856MHz signal generator BEPCII Timing System Status

5. Timing system main station layout BEPCII Timing System Status

6. Kicker e-/e+ injection timing settingsand single button injection controls. Running since the beginning of the storage ring commissioning. BEPCII Timing System Status

7. Multi bunch injection control application: read bucket pattern file and select bucket, top-up injection with high and low current restriction protection, allow changing buckets pattern and bucket swift time delay. Running since Nov. 29, 2006 BEPCII Timing System Status

8. Libera timing control: IOC logics and OPI have been created in Feb.2007.Performance: we gave accurate delay settings to trig the e- and e+ first turn BMP signal acquisition. BEPCII Timing System Status

9. E-gun timing control OPI in central control room BEPCII Timing System Status

10. Status • Besides the main station and 11 sub stations for BEPCII operation everyday, we also set up 3 test crates for timing system. Whenever new logics were asked by other groups, we first realize the logics in the test crates and then move them to the real operating crates, for example, more logics for kicker timing control and new logics for BI group first turn BPM timing control. • Experiments have been done to find the best injection timing delay settings. BEPCII Timing System Status

11. Performance: jitter of transport line beam signal to 499.8MHz RF signal is less then 16 pico seconds BEPCII Timing System Status

12. Progress • Remote control of RF signal generator (Agilent E4434B): using GPIB and Labview. Almost done. • New device support module has been created to generate 100MHz signal at EVR. • Test of EVG/EVR 230 boards on EPICSbase3.14.9at Linux is in progress: compile. • Optical-isolated modules were made to link the 10MHz time-base synchronizing line between linac and storage ring RF signal generators. BEPCII Timing System Status

13. Process: to use the BCM data • A new EPICS record support has been created to support the bucket selection with • protection to BCM hardware • Topup injection • Tripple check - using 3 methods to test the time consuming of the process. The result is around 600 us – including • find next bucket number and read BCM values from reflective memory card of BI group. If the current is large than certain value, not inject this bucket • Else - map the bucket number into corresponding SeqRAM unit, • Send new SeqRAM value to EVG • Turn on or off kicker triggers. BEPCII Timing System Status

14. New OPI logics were created to work with this new record support. BEPCII Timing System Status

15. Problem • Hardware Fail：March 19, Unit 4 of EVG SeqRAM was found not work and this position of SeqRAM was for bucket 0。Fixed: set new offset to SeqRAM to skip this unit。 • Injection phase was noticed changed in recent week, possible reason is the rising of temperature outside. More tests are wanted. Can be fixed by adjusting the fine delay setting to e-gun. BEPCII Timing System Status

16. Plans • 5 times multiplexer, VME module • Add temperature sensors in • the pipe which the timing fiber optical cable is in. • Linac klystron timing station • E-gun timing station BEPCII Timing System Status

17. Acknowledgement Work done by Ge Lei, Guanglei Xu, Lin Wang, Gang Li, Wenchun Gao, etc. Thanks to the cooperation. Thanks to the discussion with experts of KEKB, Diamond Light Source, SLS, SSRF, MRF co. Thanks to the suggestions from and cooperation with the colleagues in group of AP, BI, PS Injection, RF, Linac Power Source, Linac Microwave, and colleagues of BES. BEPCII Timing System Status

18. Thank you! BEPCII Timing System Status