IceCube DAQ Design and Performance

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(No Transcript)
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Overview

• Design Requirements
• IceCube DAQ
• Reliability, QA
• Lessons Learned
• Performance

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Design Requirements

• Reliability / Robust Design
• Remotely controllable
• Failure must not propagate
• Resistant to Radio Frequency Interference
• Hit rate is 1kHz
• Low power consumption lt 5W/DOM
• Surface temperatures -20C - -70C
• At-depth temperatures -10C - -35C

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Physics Requirements

• Timing, 7ns RMS 3ns RMS
• Waveform capture
• 300MS/s for 400ns, 40MS/s for 6.4µs
• Charge Dynamic Range
• gt200PE/15ns 500PE/15ns
• Insitu Calibration (internal and external)
• Hardware Local Coincidence

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IceCube

• 70-80 Strings
• 60 DOMs per String
• IceTop Air Shower Array on top of String

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DAQ System Overview
Ethernet
DAQ E l e c t r o n i c s
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Timedomains
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DOMHub
DOM Power Supplies
Power Distr. Card
Chassis Fans
Hard Drive
CPU
8 DOR Cards
GPS distr.
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DOM Readout Card
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Main Cable

• 0.9mm Twisted Quad Copper Cable
• 2.5km long (continuous in ice) Surface Cable
• 2 DOMs per wire pair
• Power, Timing and Communications over the same
  wire pair
• gt 50dB suppression near end cross talk
• gt 30 db suppression far end cross talk

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Digital Optical Module
Passive Base HV Supply Flasher Board Main
Board Delay Board
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DOM Main Board
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DOM Main Board
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DOM Main Board
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Altera Excalibur

• FPGA 400,000 Gates
• ARM9 CPU
• Bus bridges between CPU and FPGA
• Dual Ported Memory between CPU and FPGA
• Power consumption 0.5 0.7W

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DOM Main Board
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ATWDAnalog Transient Waveform Digitizer

• ASIC
• Switched Capacitor Array
• 4 Channels x 128 Samples Deep
• Sampling on Launch
• Sample Speed 250 - 800MSamples/s
• Digitization, 30µs/waveform
• Power consumption 125mW

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DOM Main Board
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Oscillator

• Reference time of DOM
• Short term stability
• Screened for short term stability

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DOM Main Board
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Local Coincidence

• Reduce Data Rate
• Rate without LC 1KHz
• Rate with LC lt10Hz
• Dedicated Full Duplex LC connection
• Transmit and Receive go through FPGA
• LC functionality can get reprogrammed

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Reliability, QA Overview

• DOMs are not accessible after deployment
• By Design
• Production
• Testing

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Design

• Qualified Manufacturer List
• GIDEP (Government-Industry Data Exchange Program)
• No Electrolytic Capacitors
• Derate Parts
• HALT (Highly Accelerated Lifetime Testing) Input
• Serial number electronic, barcode and human
  readable
• Robust Bootstrap boot mode
• Little Redundancy in the DOM (Deployed Spares)
• No MTBF calculations (Temperature range)

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Production

• IPC610 class 3 for Board production and loading
• No Microwelds in PCB
• Use of Industrial Temperature Parts
• Tin-Lead Parts wherever possible (NO pure tin
  parts)
• Close work with Board manufacturer and loading
  house for fast feedback
• Several Optical inspection Steps
• Digital picture of Boards after loading
• ESD Precautions

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Testing

• Initial room temperature Test
• HASS (Highly Accelerated Stress Screening)
• 48 hour Main Board burnin hot and cold
• Interface test
• Integrated DOM burnin 21 days at various Temp.
• Test before Deployment at -25C
• In Summary Testing, more Testing and even more
• All Test results are stored in Database
• ESD Precautions

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Lessons Learned

• Test Framework (bench, integration, before
  deployment and after deployment)
• DOMHub can run standalone
• Terminal Connection to DOM
• Script Language/Interpreter on DOM

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Performance

• One String and 4 IceTop Stations are deployed
• Time Calibration
• Noise/Discriminator Threshold
• Muon Reconstruction

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Time CalibrationReciprocal Active Pulsing

• Verified using
• Flasher Boards
• IceTop IceCube coincidences
• AMANDA IceCube coincidences

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Clock Stability
Time Calibration every 3.5s
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Noise/Discriminator Threshold

• PMT Gain 107
• Noise in the Ice is 800Hz
• Threshold as low as 1/8SPE

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Muon Reconstruction
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Summary

• DAQ Design
• Reliability
• One IceCube string deployed
• Four IceTop Stations deployed
• String is working very well
• All 76 DOMs function well
• In Jan, Feb up to 10 more Stings deployed
• Full Array deployed by 2009-10

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Thank You