Sub-nanosecond timing system design and development for LHAASO project

Transcription

1 Sub-nanosecond timing system design and development for LHAASO project Guanghua Gong, Qiang Du Dept. of Engineering Physics Tsinghua Univ. Beijing 13 th International Conference on Accelerator And Large Experimental Physics Control System th October 2011, WTC Grenoble, France

2 Sub-nanosecond timing system design and development for LHAASO project Guanghua Gong, Qiang Du Dept. of Engineering Physics Tsinghua Univ. Beijing 13 th International Conference on Accelerator And Large Experimental Physics Control System th October 2011, WTC Grenoble, France

3 Outline 1 Introduction LHAASO 2 Timing system requirement 3 White Rabbit application in LHAASO 4 Summary Page 3

4 LHAASO: γ astronomy and origin of CR Large High Altitude Air Shower Observatory

5 LHAASO: γ astronomy and origin of CR Large High Altitude Air Shower Observatory

6 LHAASO: γ astronomy and origin of CR Charge Particle Array Large High Altitude Air Shower Observatory

7 LHAASO: γ astronomy and origin of CR Charge Particle Array Large High Altitude Air Shower Observatory μdetector Array

8 LHAASO: γ astronomy and origin of CR Charge Particle Array Large High Altitude Air Shower Observatory Water C μdetector Array Array

9 LHAASO: γ astronomy and origin of CR Charge Particle Array Large High Altitude Air Shower Observatory Water C μdetector Array Array Wide FOV C-Telescope Array Core Detector Array

10 LHAASO detector KM2A: 5137 Electron detector, 15m spacing 1200 μ detector, 30m spacing WCDA:Water Cherenkov Detector Array m detector units WFCTA:Wide FOV Cherenkov Telescope Array 24, 300m spacing SCDA:Shower Core Detector Array Over 10,000 detector units Spread around 1Km2 area Reconstruct shower direction from timing of hits across detector Synchronous timing among detectors

11 Timing requirement 1 Support 10,000 nodes 2 clock distribution clock is used for Time-Digital-Converter High accuracy, low phase noise 3 time-stamp distribution Trigger-less readout electronics, timestamp used for event alignment To guarantee pointing accuracy in reconstruction, Timestamp offset < 1ns 4 Automatic cable/fiber propagation correction Page 11

12 Timing requirement cont. 5 High reliability, easy to maintain manual intervention is difficult 24-7 running 6 Low power consumption Heat sinking is problem Power from solar panel is limited 7 Environmental robustness Wide temperature range High altitude, thin air 8 Low cost Simple hierarchy, less items Share cable/fiber with data link path Page 12

13 Evolution of Timing Distribution Method Footer Text 10/17/201113

14 Evolution of Timing Distribution Method Footer Text 10/17/201114

15 White Rabbit Page 15

16 Possible application of Write Rabbit Page 16

17 Possible application of Write Rabbit LHAASO LHAASO LHAASO Page 17

18 WR applicability for LHAASO? -- 1 Support 10,000 nodes 2 clock distribution 3 time-stamp distribution 4 Automatic cable/fiber propagation correction 5 High reliability, easy to maintain 6 Low power consumption Environmental robustness 8 Low cost Page 18

19 Test setup Page 19

20 Test setup WR switch SPEC 6KM SM fiber Page 20

21 Test result Fiber Length Compensation Fiber PPS delay Length Mean 1 Sdev 2 30cm ns ps 1km ns ps 5km ns ps Repeatability of Recovered PPS #Run 30cm 1km 2km 3km 4km 5km Run Run Run Average Peak-Peak Link delay Note 1: the delay mainly comes from the length difference of the coaxial cables used for measurement. Note 2: the deviation mainly comes from the test signal drive circuit. Page 21

22 Test result Fiber Length Compensation Fiber PPS delay Length Mean 1 Sdev Fiber length automatically measured and 2 30cm ns ps compensated 1km ns ps 5km ns ps Repeatability of Recovered PPS #Run 30cm 1km 2km 3km 4km 5km Run Run Run Average Peak-Peak Link delay Note 1: the delay mainly comes from the length difference of the coaxial cables used for measurement. Note 2: the deviation mainly comes from the test signal drive circuit. Page 22

23 Test result Fiber Length Compensation Fiber PPS delay Length Mean 1 Sdev Fiber length automatically measured and 2 30cm ns ps compensated 1km ns ps 5km ns ps Repeatability of Recovered PPS #Run 30cm 1km 2km 3km 4km 5km Run Run Run 3The repeatability is less than ps Average Peak-Peak Link delay Note 1: the delay mainly comes from the length difference of the coaxial cables used for measurement. Note 2: the deviation mainly comes from the test signal drive circuit. Page 23

24 White Rabbit Topology in LHAASO Global Time and clock reference from GPS and Rubidium oscillator Each nodes has a Synchronization and Transmission Mezzanine Page 24

25 WR network WRS WRS RU GPS WRS WRS PC FARM ~10,000 Ports WRS #ports count! 1300 for 8port, 650 for 16 port, 330 for 32port Network management required Boundary clock cross 4 layers Certain level of redundancy is needed Page 25

26 WR in CO-HT s hardware Kit Page 26

27 An opposite situation FE for KM2A FE for ADC WCDA FPGA FE for ADC SCDA FPGA TDC ADC Memory VME TDC FPGA VME VME Memory TDC memory FPGA PLL FMC conn ector Memory FMC conn ector FMC conn ector VME VME VME WR Port STM VME format front-end electronics developed FE acts as carrier while WR in FMC Page 27

28 STM memory FPGA PLL WR Port STM The STM has the similar functionality as SPEC No carriage, No PCIe, No PWR, no SATA. Merge the SPEC into FMC form! Keep all connections compatible! Difficult but seems not impossible! Page 28

29 STM memory FPGA PLL WR Port STM The STM has the similar functionality as SPEC No carriage, No PCIe, No PWR, no SATA. Merge the SPEC into FMC form! Keep all connections compatible! Difficult but seems not impossible! Page 29

30 STM memory FPGA PLL WR Port STM The STM has the similar functionality as SPEC No carriage, No PCIe, No PWR, no SATA. Merge the SPEC into FMC form! Keep all connections compatible! Difficult but seems not impossible! Page 30

31 Summary LHAASO will be built in 5~6 years detector units need to be precisely synchronized! Timing system based on Write Rabbit technology is proposed. A demonstration has been setup and tested Page 31

32 Thank you! Page 32