WR Activities in Tsinghua Guanghua Gong, Hongming Li, Xingwei Liu, Jianming Li Dept. of Engineering Physics, Tsinghua University Qiang Du Lawrence Berkeley National Lab 8th WR workshop, CERN Gevena, 6-7 Oct, 2014

Outline Temperature effect of WR link WR deployment at YBJ@Tibet WR development at THU other WR applications in China Introduction to Ultrasync Page 2

Temp. effect measurement of FIX DELAY http://arxiv.org/abs/1406.4223 Page 3

Temp. effect calculation of FIX DELAY Only ( ∆ 𝒕𝒙𝒔 , ∆ 𝒓𝒙𝒔 ) changes with temp. δ 𝑑𝑒𝑙𝑎𝑦 𝑚𝑚 = δ ∆ 𝑟𝑥𝑠 + δ ∆ 𝑡𝑥𝑠 𝑜𝑓𝑓𝑠𝑒𝑡 =δ 𝑑𝑒𝑙𝑎𝑦 𝑚𝑠 = 1 2 δ ∆ 𝑟𝑥𝑠 − δ ∆ 𝑡𝑥𝑠 δ txs1 =−7.9𝑝𝑠/℃ δ rxs1 = 13.0𝑝𝑠/℃ δ txs2 =−8.8𝑝𝑠/℃ δ rxs2 = 13.6𝑝𝑠/℃

Temp. effect correction of FIX DELAY Take the average value (δ txs =−8.5𝑝𝑠/℃, δ rxs =13.0𝑝𝑠/℃ ) for temperature correction. Node1 Node2 Node3 reduced from 800ps to 150ps in 70 ℃ temperature range components diversity exists, node calibration needed for high precision application. Page 5

Temp. effect of fiber length The refractive index of optical fiber has temp & wavelength dependency, asymmetry coefficient 𝛂 is not constant, it has temperature dependency. Fiber length 1KM Fiber length 10KM −0.2𝑝𝑠/(℃*Km) Page 6

Temp. effect of SFP laser spectrum SFP Type AXGE-1254-0531 Tx@1310nm ”Fabry-Perot” 0.11𝑝𝑠/(℃*Km) SFP Type AXGE-3454-0531 Tx@1490nm ”Distributed Feedback” −0.51𝑝𝑠/(℃*Km) 0.4~ 0.5 nm/℃ -1.3~0.9 ps/(nm*km) -0.65~0.45 ps/(℃*km) -0.23~0.33 ps/(℃*km) 0.08~ 0.12 nm/℃ 12.9~14.4 ps/(nm*km) 1.03~1.73 ps/(℃*km) -0.87~ -0.52 ps/(℃*km) laser diode spectrum temperature efficiency G652.D Chromatic dispersion [ref] ITU-T δ ∆ 𝑡𝑥𝑠 𝑜𝑓𝑓𝑠𝑒𝑡 =δ 𝑑𝑒𝑙𝑎𝑦 𝑠𝑚 =− 1 2 δ ∆ 𝑡𝑥𝑠

WR deployment at YBJ@Tibet ARGO, Yangbajin, Tibet, 4300m a.s.l. 48 electron detectors, 2 Muon detectors GPS receiver, Rubidium frequency 4 WR switches with latest GW/SW Customized node (spec. elec with WRPC) GPS+Ru+GrandMaster ED MD Page 8

WR deployment at YBJ@Tibet WRS 50/80m fiber GM Ru GPS ED assembled 50/80m fiber 3 ED as telescope 9ED on-top of MD 100m optical power composite cable Portable Calibrate-Node

Portable Calibrate Node A Cute-WR inside box, water sealed, vibration protect Armored optical power composite cable Rugged composite connector reference PPS for field measurement Directly connected to/synced with Grand-Master switch

WR-Switch GM vs PCN WRS1,2,3 vs PCN Over 20 hours, temp range 10-26℃ PCN with temp. correction, WRS without Page 11

WR node 300 samples for each node Nodes in different locations Node index Node vs PCN (ps) Accuracy precision 2 -138 100 5 -56 28 8 12 -27 150 16 17 -15 162 24 97 156 32 -40 34 39 -28 41 42 -157 135 44 -102 26 50 -45 300 samples for each node Nodes in different locations WR integrated with detector electronics (ED & MD type) WRPC as IP core Node has been calibrated individually Power noise causes bad precision

WR deployment at YBJ@Tibet : issues Slave can’t follow time jump of master (known) TAI vs UTC DAQ-PC is running with UTC time, WR-timestamp is in TAI mode. Confusing? RTU flushing takes time?? WR-time-get response late! Net-port based status monitor Packet lost Fix-delay changes after P&R WRPC as netlist blackbox is not enough. Page 13

WR deployment at YBJ@Tibet WR is promising No serious issue, excellent experience. ~100ps accuracy with individual calibration VERY tough environment Temp, rain/snow, dust, rude operation, animal PCN is useful TDC will be integrated (no need for oscilloscope) Remote FLASH update / multiboot will be great should be integrated into all WR nodes Page 14

WR developments at THU Cute-WR with remote-updade / multiboot General for all LHAASO WR-nodes Cute-WR-DP Redundant links for high reliability (parallel mode) Mini-switch for cascade topology (chain mode) Cute-WR with TDC Page 15

WR node with TDC synchronized time tags for signals/events Distributed TDC, event logger, many applications delay chain based TDC (23ps rms) Auto calibration, real-time temp. correction, Cyclone-II/Spartan-6/Vertex-4 Bin nonlinearity need to be calibrated Auto calibration before measurement is desirable Random input signals only available in special applications Dedicated calibrate signal Special OSC / Cascade PLL W.Jin RT2014: Uneven Bin Width Digitization & Cascade PLL DNL Histogram In (bin) LUT S Out (ps) Pulses with evenly spread timing relative to the TDC clock DMTD helper-clock WR-clock Get it for free, Bonus of WR

other WR applications in China CSNS (China Spallation Neutron Source) Apply WR for T0 arrival time measurement ~50 nodes, 2KM distance, 50ps time resolution JUNO (Jiangmen Underground Neutrino Observatory) apply WR for under-water readout-box time-sync ~1000 nodes, 150m distance, fiber must be LS compatible under water connectors, high reliability ADS (Accelerator Driven Sub-critical System) Apply WR as event logger for beam protect system 10 nodes, 200m distance, high reliability CJPL (China Jinping Underground Laboratory） Deepest underground lab, 7500 M.W.E. Dark-matter / Neutrino experiments, low background facilities General time/frequency distribution for 9 experiment halls Page 17

Introduction to Ultrasync Academic spin-off of THU New partner in OHWR community Current: OHWR distributor (import/export) Cute cards production WR consultation & promotion in China Future: WR related development WR installation/commission/maintainess www.ultrasync.com.cn ---under construction Page 18

sweet! White Rabbit is synchronous, precise, robust and