Sep 22, 2016 Calorimeter

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Video Conferencing Information

Meeting Time: 11:00 a.m.

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Participant Direct Lines

  • JLab Phone: in CC F326 is 757-269-6460 (usual room)
  • JLab Phone in CC L207 is 757-269-7084
  • Phone in the Regina Video-conference Suite is 306-585-4204
  • Athens Phone: in Christina's office is 011-30-210-727-6947

Action Items

  • Produce documentation for implementation of timing algorithms and constants (Andrei)


  1. FCAL HDFCAL log book
  2. BCAL HDBCAL log book
  3. BCAL Action Items and Working Tasks

Tentative Agenda

  1. Announcements
  2. Collaboration Meeting In two weeks!
  3. Action Items
  4. Preparation for REST production
  5. FCAL update
  6. BCAL update
    1. BCAL LED plugin [2]
  7. Calibrations
    1. FCAL Timing Vs Energy File:FCALTimingSlope.pdf
  8. Reconstruction and Simulation
  9. Any other business


Attendees:Elton, Mark, Adesh (JLab); Sean (NW); Zisis, Ahmed, Andrei (Regina); Matt (IU); Will, Mike, Curtis (CMU); George, Christine (Athens).

  1. Announcements
  2. Collaboration Meeting In two weeks!
    • We decided on two talks: Fcal (Adesh) and Bcal (Will)
  3. Action Items
    1. Documentation on timing algorithm in progress.
      • Irina and Andrei are running simulations to account for dE/dx changes to reconstruction. So far only pions, which have little ionization loss, have been run and show little effect.
      • Andrei will rerun their calibration using the new clusterizer code that Will has implemented.
  4. Preparation for REST production
    • No changes. Studies continue on why ver2 is worse than ver1. The FDC reconstruction is suspect.
  5. FCAL update
    1. Bases
      • Jon and Adesh replaced 22 bases.
      • The db has updated.
      • There are now one (new base) that cannot hold voltage and 3 bases that have communication problems. The communication issues may clear up upon recycling the power
      • Hardware has been implemented to recycle the power remotely, but has not been completely implemented yet. This will allow recycling power during the run without a need for an access.
    2. New data
      • Sasha has added a Log Entry 3421770 with a list of new configuration files for Fcal and Bcal
      • We will try to take data with the stand alone systems.
      • Sean: took a quick look at the new files with the updated format. He believes the decoding needs some work, but it appears there are some missing fields in the data also.
      • Mark: Example? Sean: The field with the event number in the block is zero but should have a value between 1-255. Also the number of samples in the pedestal is absent. These may be due to poor initialization (?)
  6. BCAL update
    1. Status (Elton)
      • BCAL has been on for a couple of weeks and recycled through the power outages
      • All LV and biases are on.
      • LED LV and bias were also turned on, but one bias input trips. Chris is diagnosing the problem; it appears to be a break in the voltage sense circuit.
    2. BCAL LED plugin [3]
  7. Calibrations
    1. Sean
      • Draft updates have been made to the calibration hit factories.
      • Ready to take a look at the files with the updated firmware to check that everything is ok
      • Bcal has a well-defined procedure for looking at the LED data. Question: Is there a procedure for Fcal?
      • Adesh: The plan is to increase the bias on the LEDs so that the input pulses are increased (at the moment they are a about 20 counts above pedestal). They will check that all inputs are operational and take a look at different LEDs.
    2. Fcal
      • Testing calibration plugging with ROOT 6 to verify there are no problems.
      • Work continues on timing offsets
    3. omega->pi0->3g (Mike)
      • After reconstruction, the analysis picks the "bachelor" photon. The time of this photon is compared to the expected time from other information in the event. The time difference (expected - measured?) depends on the energy of the photon.
      • Matt: What is the sign of the difference? Mike: Need to confirm the meaning
      • There are at least to mechanisms that could contribute: 1) time walk 2) systematic time differences for light to arrive at the pmt depending on the shower development and Cherenkov light propagation in the glass. This is related to the z correction.
      • Elton: Should check time dependence on geometry (e.g. radius) to see if the dependence on energy is indirect
      • Mark: Could be due to incorrect z correction in the code. However, the scale is 1 ns ~ 18 cm in the glass, which is the depth of the shower.
    4. Track matching (Sean)
      • Sean showed some improvement in the track matching to the Bcal yesterday. There has been improvement with the new software. The efficiency is uniformely about 85%till the end where it drops down to about 50%. The drop may be due to tracking in the FDC.
      • Mark: What is the algorithm for the matching? Sean: will need to report back.
    5. Error matrices (Mark)
      • Has computed variances and covariances for the BCAL and FCAL using thrown photons with E,theta.
      • Still need to test the matrices with the kinematic fitter. Is waiting for Paul to have time to help
      • Paul wants to solve the tracking issues first before tackling the calorimeters
      • Document has been written and will be posted on DOCdb later today. Comments and feedback are welcome.
      • Matt: Took a quick look at the variances and covariances for the FCAL and they looked reasonable at fist glance.
    6. FCAL Timing Vs Energy File:FCALTimingSlope.pdf
      • Plots monitor signal for each configuration divided by the average for that run.
      • These ratios are tracked for each configuration as a function of run number.
      • There are some changes (jumps) in calibrations throughout the run period, which are not quite understood. Many of them are changes in an entire quadrant.
      • The mechanism for implementing the monitoring online and offline has not been decided. One option would be to store reference values in CCDB. For online, Mark mentioned that "standard" histogram files could be used as references in ROOTSPY
      • Elton: Suggests that the system be made to work reliably offline before trying to integrate into the online system. Ahmed and Zisis will work on specific proposal for implementation, which can be circulated by e-mail for comments.
    7. veff calibrations (George)
      • Verifying that the veff calibration is compatible with ROOT6
      • Checking that the upgrades to the tracking (and any other analysis changes) do not affect the veff procedure.
  8. Reconstruction and Simulation
  9. Any other business
    • Christina: George's masters thesis is due in to weeks on omega->3pi/eta->3pi