IMAC 2007 BEPCII Timing System Status 1

Event timing system for BEPCII storage ring commissioning

Presented by G. LeiMay 2007

IMAC 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

IMAC 2007 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.

IMAC 2007 BEPCII Timing System Status 4

BEPCII timing system layoutBlue lines: event system optical cablesRed lines: 499.8MHz signals Green line: 10MHz time base synchronized with Linac 2856MHz signal generator

定时主站

谱仪定时站

RF东厅

束测定时站

e-Ki cker定时站

e+Ki cker定时站

e+同步光定时站

e-同步光定时站

RF西厅

输运线定时站

LBI定时站 调制器

定时站 电子枪定时站

2856MHz源

参考磁铁屋

IMAC 2007 BEPCII Timing System Status 5

Timing system main station layout

Agi l ent E4434BSi gnal Generator

MVME

5100

EVR-

RF

EVG

FOUT-7FOUT-7FOUT-7

FOUT-7

50Hz源

分功器组

分功器组

NI M相控用 机箱

示波器

主定时VME机箱

定时调试检测站

光端盒光端盒

EVR-RFI OC

EVR-RF

EVGI OC

EVR-RF

IMAC 2007 BEPCII Timing System Status 6

Kicker e-/e+ injection timing settings and single button injection controls. Running since the beginning of the storage ring commissioning.

IMAC 2007 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

IMAC 2007 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.

IMAC 2007 BEPCII Timing System Status 9

E-gun timing control OPI in central control room

IMAC 2007 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.

IMAC 2007 BEPCII Timing System Status 11

Performance: jitter of transport line beam signal to 499.8MHz RF signal is less then 16 pico seconds

IMAC 2007 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 EPICSbase3.14.9 at 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.

IMAC 2007 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.

IMAC 2007 BEPCII Timing System Status 14

New OPI logics were created to work with this new record support.

IMAC 2007 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.

IMAC 2007 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

IMAC 2007 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.

IMAC 2007 BEPCII Timing System Status 18

Thank you!