Michael Beimforde

1
IceCube trigger
IceCube trigger

• Michael Beimforde
• Group Meeting, December 1, 2006

2
Outline - DAQ - LC - Trigger - Summary

• Outline
• DOM DAQ
• LC
• Software triggers
• Summary

December 2006, Michael Beimforde, 2/78
3
Outline - DAQ - LC - Trigger - Summary

• DOM DAQ
• PMT coupled via input transformer
• Trigger / discriminator of typically 0.3 PE

• If signal above threshold
• Signal is given time stamp in FPGA, data taking
  initiated, signal waiting 75ns in delay board

• ATWD started by FPGA and filled with signal

• Checking for LC in given time window (II?1000ns,
  IT?125ns dataio-shovel), if not found readout
  is stopped

• else -gt GOTO DOR CARD!

December 2006, Michael Beimforde, 3/78
4
Outline - DAQ - LC - Trigger - Summary

• 1 Station 2 tanks

• IceTop

• LC cross connection

high
low
high

• no big problem if low gain DOM fails

• bigger problem if high gain DOM fails

• switch low gain to high gain

• InIce

• equal gains

high (see small signals)
low

• no really big problem if a DOM dies

December 2006, Michael Beimforde, 4/78
5
Outline - DAQ - LC - Trigger - Summary

• From hits to events
• LC triggered DOMs send data to DOR cards in
  DOMHubs.
• Via std. ethernet data goes to IT data handler
  and String processor hits are grouped and time
  sorted.
• Apply sub-detector software triggers (InIce /
  IceTop)
• Global trigger will consider the sub-detector
  triggers and sends a global trigger (or not)
• Event Builder takes the triggered event and
  builds a data set that is understood by the
  analysis software.

1.
2.
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5.
December 2006, Michael Beimforde, 5/78
6
Outline - DAQ - LC - Trigger - Summary

• IceCube software triggers
• There are currently five defined
• Documentation is poor
• ... sorry for the lack of documentation. It is
  a real problem that will hopefully be fixed soon
  ... (Pat Toale)
• Configurations are stored in the DAQ database
  (which is not really accessible)
• They can also be read in by a configuration xml
  file

December 2006, Michael Beimforde, 6/78
7
Outline - DAQ - LC - Trigger - Summary
Always triggered by GT (with Throughput and
Coincidence)
group of hits that triggered
InIce SMT
timeMinus2us
IceTop SMT
Global
timePlus8us
Only triggered with Troughput GT
InIce CAL
IceTop SMT
Global TT
December 2006, Michael Beimforde, 7/78
8
Outline - DAQ - LC - Trigger - Summary
December 2006, Michael Beimforde, 8/78
9
Outline - DAQ - LC - Trigger - Summary
Standard physics runs rates (bugged!). Real rate
about 140 Hz (S. Schlenstedt)
(Pat Toale April 2006)
December 2006, Michael Beimforde, 9/78
10
Outline - DAQ - LC - Trigger - Summary

• Summary
• DOM discriminator and LC are hardware triggers
  (dataio-shovel -gt I3DetectorStatus)
• The rest happens in software on standard PCs
• Triggering is poorly documented and not very
  flexible
• (DAQ has to be reinstalled if triggers are
  changed (Th. Schmidt))
• Config XML is easy to understand but not easy to
  access
• Keep the questions coming, if I answer enough I
  can just post these emails on a wiki and call it
  documentation. (Pat Toale)

December 2006, Michael Beimforde, 10/78