sin 22 q 13 Measurement at reactors e

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sin 22 q 13 Measurement at reactors νe νe νe Well understood, isotropic source

sin 22 q 13 Measurement at reactors νe νe νe Well understood, isotropic source of electron anti-neutrinos νe νe Oscillations observed as a deficit of νe Detectors are located underground to shield against cosmic rays. νe Probability νe 1. 0 sin 22θ 13 Unoscillated flux observed here πEν /2Δm 213 Distance (L) 7 th 高能物理学会大会, 李小男, 高能物理研究所 1500 meters 2

Dayabay Reactor Neutrino Experiment 900 m 465 m 810 m 607 m 292 m

Dayabay Reactor Neutrino Experiment 900 m 465 m 810 m 607 m 292 m Total Tunnel length ~ 3000 m 7 th 高能物理学会大会, 李小男, 高能物理研究所 3

Detecting e • Inverse -decay in 0. 1% Gd-doped liquid scintillator • Antineutrino signal,

Detecting e • Inverse -decay in 0. 1% Gd-doped liquid scintillator • Antineutrino signal, algorithm implemented in offline or on online computer farm – Time coincidence – Energy correlated 7 th 高能物理学会大会, 李小男, 高能物理研究所 4

Requirements of readout electronics • Readout board designed for all detector systems except RPC.

Requirements of readout electronics • Readout board designed for all detector systems except RPC. • Neutrino detector: – Charge measurement • Dynamic range for each PMT: 0 PE -- 500 PE – 50 p. e is the maximum for a neutrino event – ~500 p. e. for through-going muons • resolution: <10% @ 1 p. e, 0. 025%@ 400 p. e. • Noise < 0. 1 p. e. • Digitization time(mainly shaping time) < 1 ms – Timing measurement: • To determine event time and event vertex • dynamic range: 0 ~ 500 ns • resolution: < 500 ps • Muon detector: – Water pool: Same requirements as neutrino detector – Water Tracker: Hit and/or charge • RPC: BESIII electronics 7 th 高能物理学会大会, 李小男, 高能物理研究所 5

Readout board diagram On board calibration circuit TDC algorithm: Gray counters 16 Channel inputs

Readout board diagram On board calibration circuit TDC algorithm: Gray counters 16 Channel inputs 7 th 高能物理学会大会, 李小男, 高能物理研究所 6

Trigger requirement • Good background rejection power rate can go to ~KHz rate limited

Trigger requirement • Good background rejection power rate can go to ~KHz rate limited by DAQ capabilities (hopefully < 10 MB/s/module) • Low threshold ( T+3 s < 1 Me. V ) – Record prompt positron signals and delayed signals from the neutrino interactions. – Record the background to enable background analysis. • High and well known efficiency • Flexibility (to fight backgrounds), same trigger board for different detector. – FPGA – Daughter card • Reliability (to reduce systematic errors) • Independency, Separate trigger for each of neutrino module, and each of muon detector, water pool, water cenrenkov module and RPC. • Redundancy (to measure the trigger efficiency) • Provide a system clock 7 th 高能物理学会大会, 李小男, 高能物理研究所 7

Algorithms • Central trigger: OR of the following two – Energy: total charge >

Algorithms • Central trigger: OR of the following two – Energy: total charge > 15 PE – Multiplicity: > 15 PMT fired • Veto trigger: OR of the following two – RPC: > two hits in any plane (Scin. > 1 hits ) – Water: > few PMT fired • Prompt and delayed sub-event triggered and recorded independently, time correlation offline • Central and veto events triggered and recorded independently, time correlation offline • No dead-time induced. Trigger rate is limited by electronics recover time and by DAQ bandwidth. • Trigger type: – – – Primary physics trigger LED Radioactive source Periodic trigger Muon trigger 7 th 高能物理学会大会, 李小男, 高能物理研究所 8

PMT dark current rate • PMT max. number: 200 • PMT dark current rate:

PMT dark current rate • PMT max. number: 200 • PMT dark current rate: 50 k • Integration windows: 100 ns 7 th 高能物理学会大会, 李小男, 高能物理研究所 9

Trigger rate Detector Event Trigger Rate Occ. Ch size (bits) 100% 224*64 DB LA

Trigger rate Detector Event Trigger Rate Occ. Ch size (bits) 100% 224*64 DB LA Far Cosmic-μ 36 x 2 22 x 2 1. 2 x 4 Rad. 50 x 2 50 x 4 Pool Cosmic-μ 250 160 13. 6 50% 340(252)*64 Tracker Cosmic-μ 1390 819 57. 8 100% 8*64 Cosmic-μ 260 415 10% 7650(5040)*1 e Module RPC Rad. &Noise Site totals k. B/s 186 117 653 483 10. 5 419 7 th 高能物理学会大会, 李小男, 高能物理研究所 1555 10

Trigger board • One board per module • Same hardware design for central and

Trigger board • One board per module • Same hardware design for central and veto board • Each trigger board can handle up to 256 PMTs • Decision time: → Readout event buffer depth – Multiplicity trigger based on FPGA: ~ 200 ns – Energy trigger based on total charge : ~ 300 ns ? • System clock + Local clock 7 th 高能物理学会大会, 李小男, 高能物理研究所 11

Timing • Each site has a master clock to synchronize the veto and central

Timing • Each site has a master clock to synchronize the veto and central modules • A GPS time/1 PPS/10 k. Hz reference will be delivered to each site for an absolute time stamp • If GPS can not be used, we can use a local clock, a problem for Supernova studies. • Precision: GPS time ~ 100 ns. Time-stamp precision level 25 ns. • Each trigger board have a local clock for self trigger and testing. Mid-site DYB 7 th 高能物理学会大会, 李小男, 高能物理研究所 LA FAR 13

Data acquisition & online control • VME based front-end hardware, Motorola Power. PC controller

Data acquisition & online control • VME based front-end hardware, Motorola Power. PC controller • RT-Linux RTOS: Time. Sys Co. Linux. Link • Back-end Linux PC. Software based on BES-III/Atlas Framework • Each detector system and each neutrino module at each site is readout (trigger) independently. – 8 antineutrino streams and 9 muon streams. Event reassembled using timestamp offline. – One neutrino module → One VME crate. – Water pool → One VME crate (near), Two VME crates (far). – Water Cerenkov Module system: TWO VME crates. • Communication: – Copper between trigger-FEE – Twisted cable between Power. PC and readout computer – Optical between site-site/site-surface. 7 th 高能物理学会大会, 李小男, 高能物理研究所 15

Data acquisition and online control • Online control – Local online control in each

Data acquisition and online control • Online control – Local online control in each detector hall: each detector system has its own online control. Detector debugging and commissioning in parallel. – Global online control in surface room: Operate and monitor all detector system. • Data storage: – Data throughout: 1. 5 MB/s. → 0. 4 TB/day (safety factor of 3). – Local tapes – Local disks • Data transfer: – Tapes from DYB to IHEP or to Shenzhen Uni. – A data link from Shenzhen Uni. to IHEP via network can be discussed • A data center at IHEP to be established. Raw data or processed data tapes will be copied and shipped to other data centers in the world, or distributed via GRID. 7 th 高能物理学会大会, 李小男, 高能物理研究所 16

Status • Simple version of readout boards and trigger board are successfully running on

Status • Simple version of readout boards and trigger board are successfully running on the prototype. • We are working on the 2 nd version of readout board and trigger board • We finished conceptual design of DAQ • DAQ group is formed and begin to work on the project 7 th 高能物理学会大会, 李小男, 高能物理研究所 18