Difference between revisions of "Apr 5, 2018 Calorimeter"

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##* Has been studying the charged clusterizer.
 
##* Has been studying the charged clusterizer.
 
##* Lubomir and Sean have identified some J/Psi events that were eliminated when analyzed with the charged particle clusterizer.  This was due to some hits added to the cluster that had crazy z values, which affected the cluster parameters.
 
##* Lubomir and Sean have identified some J/Psi events that were eliminated when analyzed with the charged particle clusterizer.  This was due to some hits added to the cluster that had crazy z values, which affected the cluster parameters.
##* Will is working on a local branch that adds z position and timing criteria before including hits into the cluster. With these changes, all J/Psi events are recovered.
+
##* Will is working on a local branch that adds z position and timing criteria before including hits into the cluster. With these changes, all J/Psi events with this problem are recovered (about 5% of all J/Psi lost).
 
##* The present idea is to include these odd hits into the energy computation (as done for single-ended hits), but not to change other parameters of the cluster
 
##* The present idea is to include these odd hits into the energy computation (as done for single-ended hits), but not to change other parameters of the cluster
 
##* Checking the effects of the revised code affects cluster parameters in only 0.15% of the cases.
 
##* Checking the effects of the revised code affects cluster parameters in only 0.15% of the cases.

Revision as of 15:38, 5 April 2018

Video Conferencing Information

Meeting Time: 11:00 a.m.

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Participant Direct Lines

  • JLab Phone in CC L207 is 757-269-7084 (usual room)
  • JLab Phone: in CC F326 is 757-269-6460
  • 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

Homework from NIM paper

  1. Non-linearity correction of SiPMs (Elton)

Complete after new launch

  1. Report back on study of eta with in FCAL [Mark]
  2. From Mike's work: -cos(phi) type dependence in the data and a phi dependence at the downstream end of the bcal

References

  1. FCAL HDFCAL log book
  2. BCAL HDBCAL log book

Tentative Agenda

  1. Announcements
  2. Action Items
  3. FCAL Update
    1. Run related
    2. Other updates
  4. BCAL update
    1. Run related
      • Hot channel M25 L4 S4 Upstream introduced when FADC module replaced. Fixed with new FADC.
      • Incident on Monday evening (~5:30 pm) BCAL bias voltages did not hold. It appears this was due to poor coordination between Sasha and Counting Room. See Log Entry 3553711.
    2. Other updates
  5. Calibrations
    1. Spring 2018 Calibrations
  6. Monitoring
    1. BCAL LED monitoring update (Ahmed)
  7. Reconstruction and Simulation
    1. Charged Particle Clusterizer (Will)
    2. FCAL Shower and Split-offs
    3. BCAL Hadronic Efficiencies (Elton)
  8. NIM articles
    • BCAL NIM article accepted for publication!
  9. Any other business

Minutes

Attending: Mark, Elton (JLab); Will, Curtis (CMU); Ahmed, Tegan (UofR); Jon (IU); Lei, Rupesh, Tolga (FIU); Sean (FSU)

  1. Announcements
  2. Action Items
  3. FCAL Update
    1. Run related (Note from Colin)
      • Log Entry 3554271 Recent base replacement
      • One thing to bring up at the meeting that I mentioned last meeting was that bases drop HV/fail at a faster rate with beam on target than without. During the 3 wee shutdown, only 3 bases dropped HV. During the week we had beam, 6 bases dropped HV. Note that the LEDs were on the whole time the accelerator was down. We thought it was just coincidental at first, but since the failure rate has increased again I do not think it is coincidental. Some interesting questions:
        • Is this rate dependent? If this was so, we'd see more bases fail at the center of the FCAL than at the edges. Since we don't see this, it does not appear rate dependent. This hasn't been studied in detail, just general observations made.
        • Is it radiation (ie neutrons)? If it is radiation causing this, then we'd expect other components in the base to fail on a regular basis. Since replacing 2 damaged resistors fixes the HV issues, it's unlikely this as we'd expect other components to be damaged. Why don't other electronics on the FCAL platform die regularly? Are there radiation maps fo the hall, or sensors near the FCAL to check/test this?
        • PMTs drawing more current? Maybe the bases/PMTs are drawing more current and causing them to fail when we have beam.
        • Any other ideas? This isn't a major issue, just an observation that doesn't have a clear answer.
    2. Other updates
  4. BCAL update
    1. Run related
      • Hot channel M25 L4 S4 Upstream introduced when FADC module replaced. Fixed with new FADC.
      • Incident on Monday evening (~5:30 pm) BCAL bias voltages did not hold. It appears this was due to poor coordination between Sasha and Counting Room. See Log Entry 3553711.
    2. Other updates
  5. Calibrations
    1. Spring 2018 Calibrations
    2. BCAL (Mark)
      • New attenuation length and gain ratios completed.
      • z-position calibrations will be processed soon. So far 2017 and 2018 show similar trends so no major changes expected.
      • There was some discussion whether Tegan should wait for the z-calibration.
      • Sean: There have been many tracking changes. Mark: This will only affect which events are used in calibration.
      • Mark: Start iterating. Final iterations will be necessary after new calibrations are updated, but initial work will not be lost.
      • Sean has updated the ccdb with values from Tegans latest work.
  6. Monitoring
    1. BCAL LED monitoring update (Ahmed)
      • Run range used is 40660-51590 with latest skimmed files
      • Showed examples of good channels, that showed a very small slope (<1%) vs run number. This is attributed to the pulser system since both upstream and downstream show the same trend.
      • Mark : To see if there is a slope, fit the data and check statistical significance.
      • Three problematic channels (changes of >1% vs run number). These were seen last year (all upstream): M26 L3 S2, M29 L1 S1 and M29 L2 S2
      • Will: Suggestion to fit data vs run number and plot slope and offsets in a summary plot that incorporates all channels.
  7. Reconstruction and Simulation
    1. Charged Particle Clusterizer (Will)
      • Has been studying the charged clusterizer.
      • Lubomir and Sean have identified some J/Psi events that were eliminated when analyzed with the charged particle clusterizer. This was due to some hits added to the cluster that had crazy z values, which affected the cluster parameters.
      • Will is working on a local branch that adds z position and timing criteria before including hits into the cluster. With these changes, all J/Psi events with this problem are recovered (about 5% of all J/Psi lost).
      • The present idea is to include these odd hits into the energy computation (as done for single-ended hits), but not to change other parameters of the cluster
      • Checking the effects of the revised code affects cluster parameters in only 0.15% of the cases.
      • Elton: When will the work be completed? Will: Energy calculation will be added similar to the case of single-ended hits. Then checks need to be completed and this will take most of the time.
      • Curtis: Should one use neutral clusterizer for electrons? Sean: There has been some discussion of making electrons a special case of neutral clusterizer.
    2. FCAL Shower and Split-offs (Matt)
      • In Matt's absence, Sean summarized the work posted to the e-log.
      • Matt has been working with an undergraduate to use neural networks to identify clean showers. The result is a quality factor assigned to clusters < 1 GeV assessing the probability that they are a good cluster and not a split-off.
      • Based on this criteria for combinations of two photons can clean up the inclusive 2pi0 mass spectrum considerably.
      • There has been discussion on where to include this analysis and was decided to add the quality factors to the output REST file. (This is on Sean's to-do list). The factors can allow shower cleanliness selections after REST files are produced.
    3. BCAL Hadronic Efficiencies (Elton)
      • Showed the computed BCAL Hadronic Efficiencies vs run number for ver11 of the reconstruction.
      • The data show a trend toward lower efficiencies (~1%) for layers 2 and 3, comparing to previous ver07 runs.
      • Sean: Noted that ver11 is only for special runs of various kinds. Should check data from ver10. Elton: Did not see the ver10 files, but will check with Alex A.
  8. NIM articles
    • BCAL NIM article accepted for publication!
  9. Any other business