HCAL%20test%20beam%20monitoring%20-%20online%20plots%20

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HCAL test beam monitoring- online plots fast
analysis -
Marius Groll

• what do we want to monitor
• how do we want to store communicate information

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HCAL status

• HCAL Prototype
• 1 m3
• 8000 calorimeter tiles equipped with SiPM
• 6 layers now ready
• assembling of the next modules has been started
• Minimum for CERN test beam 18 layers ECAL
  TC? high number of channels? how to control
  and check them?? how to establish a fast
  feedback during data taking?

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HCAL monitoring

• We would not work with dirty data (it will be
  meaningless) Vasiliy Morgunov, May 2004
• What do we have to monitor?
• Beam properties
• Positioning of the detector
• HCAL detector properties dead and noisy channels
• How to we communicate developments/changes?
• Predefined checklists and logbook entries for the
  test beam crew
• Database entries for the analysis team

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HCAL monitoring software

• All used software should be very comfortable,
  user friendly and stable
• Software checks on recent taken data
• Three parts
• DAQ provided online displays on an additional
  DAQ-PC, which is using ROOT-Map file? mean and
  noise averages? data taking stability
  checksidentical information for ECAL HCAL are
  already provided at this stageBUT some
  improvements are needed- real pedestal
  subtraction is needed- indications for the
  non-expert acceptation band in histogram /
  reference histogramse.g. What is a fluctuation
  and what is a shift in pedestal position and
  pedestal width?

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HCAL monitoring software

• Data quality checks by the shift crew
  (Semi-online) has to be based on event
  information and has to provide fast
  feedbackprobably different tasks for ECAL
  HCALTask1. check and test the monitoring and
  calibration quality2. identify dead and noisy
  channels and label them
• - diagnostic of wrong pedestal position or its
  width - diagnostic of readout electronics
  overflow in ADC, non-linearity of ASIC -
  diagnostic of coherent noise (1 chip, 1 cable, 1
  FE)

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HCAL monitoring software

• Data quality checks by analysis team _at_ home
  (Near-offline / LCIO monitoring)
• Task check changes in calibration in detail
• - diagnostic of change in MIP peak position or
  its width- diagnostic of change in SiPM gain
  single photon resolution- diagnostic of unusual
  channel spectrum (long discharge)

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HCAL monitoring software

• How to do this particular at CERN?
• Online DAQ online histograms
• Semi-Online binaries or on-the-fly conversion ?
  on-the-fly conversion has the advantage of
  reusability of the code in the final LCIO based
  analysis,but it is dependent on the converter
  status? will there be a DAQ software change
  during this period? When the DAQ and the
  software will be frozen for the test beam?
• Near-Offline LCIO/Marlin/LCCD based analysis on
  the converter output ? do we need a PC for this
  at the test beam?
• a lot of channels (HCAL alone 4000-8000) used in
  different modes? a lot of plots!! ? large
  screens are needed / is there a printer?

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data taking check lists

• How do we take track of the observed
  changes?Some predefined information has to be
  written in the logbook/check list for the shift
  crew? has to be done regularly and after access
• Development of user check list to monitor
  changes
• Give update to next shift crew
• Check HV and LV
• Check DAQ errors, timeouts
• Check trigger rate are triggers occuring at a
  reasonable time
• Check histograms? which channels behave strange
• Have recent files been written correctly to the
  HDD converter job and backup

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Event display

• ECAL has a beautiful event display
• we also tried something? far away from the
  ECALstatus? lets try not to duplicate it? a
  combined event display would be the goal
  (switches to turn HCAL/ECAL/TC on/off)

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Beam quality and control

• Beam properties effect the shower reconstruction
• Clean beam is needed / clean the data offline
• available wire chambers and cherenkov must be
  implemented in DAQ readout
• Goals for the offline analysis
• Beam energy resolution should be in 1 - 2 range
• Good particle purity (better than 1 additional
  particles)
• Beam spot size should be 2x2cm2 (3x3cm3) and
  particle position monitoring on the 1mm level
• What are the beam background conditions halo
  size and gammas
• Muon trigger behind calorimeter 10x10 cm2 to get
  clean sample?
• MIP trigger in parasitic calibration mode? ? how?

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Conclusion

• We agree on the three monitoring stages, pointed
  out in the UK-ECAL task list (online,
  semi-online, near-offline (LCIO))
• We have a lot of different tools, but we still
  have to make an user-friendly monitoring/analysis
  program to get fast feedback like George and Götz
  have done it for the ECAL
• ? this is the goal for the combined test beam at
  DESY in April-
• This combined test beam rehearsal will be a major
  step to the running monitoring at CERN