Difference between revisions of "September 24, 2014 Calibration"

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* Mark I. pointed out that changing the DAC values on the fADC's is not the same as calibrating the pedestals.  There was much discussion on this point.  Eugene pointed out that its reasonable to call it a pedestal "adjustment".
 
* Mark I. pointed out that changing the DAC values on the fADC's is not the same as calibrating the pedestals.  There was much discussion on this point.  Eugene pointed out that its reasonable to call it a pedestal "adjustment".
 +
 +
'''Trigger'''
 +
 +
* We then looked at the wiki page for the trigger commissioning plan.  This was discussed in the trigger meeting on Monday, substantial changes were suggested, but it hasn't been updated since then.
 +
* Probably we will start with just an FCAL trigger before bringing in the BCAL
 +
** One big question is if we need to exclude the inner rings of the FCAL from the trigger.  This will require seeing the actual beam.
 +
* Another outstanding question is if we can read out the whole detector.  So far, nearly all ROCs have been read out at once, but not all of them.  There have been problems reading out over VME. 
 +
 +
'''TDCs'''
 +
 +
* Elton brought up the topic of how to treat the TDCs for discussion.  The problem is that normally we would use the RF times as a reference for the times reported from the TDCs, but we will not have that this fall.
 +
* There was much discussion on how to handle this.  The best suggestions seemed to be to use the Start Counter, Pair Spectrometer, or Tagger times as reference, if possible.  The trigger time has too much jitter and is not precise enough to use as a reference.
 +
* The fADCs do have good timing capabilities, but we would like to be able to commission the TDCs this fall.
 +
* Elton will gather opinions for a discussion during the Collaboration Meeting.,
 +
 +
===Simulations===
 +
 +
* Simon has updated the commissioning simulations with an extended model of the beamline geometry and an extended target region, including the plastic beampipe cap and the air the photon beam will have to pass through. 
 +
* Simon and Sean have been looking at detector rates.
 +
 +
===Data Monitoring===

Revision as of 00:20, 25 September 2014

GlueX Calibration Meeting
Wednesday, September 24, 2014
11:00 am, EDT
JLab: CEBAF Center, F326

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Agenda

  1. Announcements
  2. Collaboration Meeting
  3. Commissioning Planning updates
    1. CDC
    2. FDC
    3. FCAL
    4. BCAL
    5. TOF
    6. Start Counter
    7. Trigger
  4. Fall 2014 Commissioning Simulations updates
  5. Data Monitoring
    1. Commissioning Plan
    2. Data Monitoring Database & Histograms
  6. AOB


Minutes

Attending: Sean, Amiran (NU); Mark I., Simon, Beni, Eric, Andrei S., Mike S., Mark D., Eugene, Elton, David L., Sergey F. (JLab); Curtis, Paul, Naomi (CMU); Matt (IU); Ahmed, Noemi, Tegan, Zisis (Regina); Justin (MIT); Brenden P. (UConn); Kei (ASU)

Announcements

  • The latest accelerator schedule has the machine starting around Oct. 9
  • David L. has written up new documentation about Online Monitoring plugins
  • David also mentioned that Sergey F. has a new system for loading the DAC values onto the readout boards. It will be discussed in more detail in the online meeting in the afternoon.

Commissioning Planning updates

CDC/FDC

  • Beni reported that there have been problems with the CDC DAQ since the new fADC125 firmware was installed, with a variety of problems showing up on different boards. It's unclear at this point if it's a problem with the boards or the firmware.
  • The new fADC125 firmware does report pedestals - modes 1,2,3,4, and 8 are supposedly supported.

FCAL'

  • John Z. is working on integrating the pi0 calibration code into a DANA plugin.
  • Matt asked about the documentation for the Online_Monitoring_plugins.

BCAL

  • Incremental progress is being made at Regina. Andrei and Noemi are looking at low-level calibration values, mainly with cosmic data. A long-standing confusion about cosmic rates has been lately understood.
  • Will McGinley is looking at BCAL calibrations using pi0's and making progress estimating rates.

TOF

  • FSU has collected 2M cosmic events. Sasha O. is working to understand these data and refine his calibration programs. There are some difficult parts to understand in the data, but this is mostly because the cosmic tracks are more vertically oriented than tracks from photon beam reactions. Photon beam data is expected to be much easier to understand. There should be enough information by now to make a good-enough global alignment of the TOF, and Sasha is pursuing this.

Start Counter

  • The first version of the fADC250 DAC adjustment has been made. The characteristics of the polished paddles are different than those of the prototypes used to study calibration procedures before, so they will have to be looked at afresh, probably with photon beam data.

Interlude

  • Mark I. pointed out that changing the DAC values on the fADC's is not the same as calibrating the pedestals. There was much discussion on this point. Eugene pointed out that its reasonable to call it a pedestal "adjustment".

Trigger

  • We then looked at the wiki page for the trigger commissioning plan. This was discussed in the trigger meeting on Monday, substantial changes were suggested, but it hasn't been updated since then.
  • Probably we will start with just an FCAL trigger before bringing in the BCAL
    • One big question is if we need to exclude the inner rings of the FCAL from the trigger. This will require seeing the actual beam.
  • Another outstanding question is if we can read out the whole detector. So far, nearly all ROCs have been read out at once, but not all of them. There have been problems reading out over VME.

TDCs

  • Elton brought up the topic of how to treat the TDCs for discussion. The problem is that normally we would use the RF times as a reference for the times reported from the TDCs, but we will not have that this fall.
  • There was much discussion on how to handle this. The best suggestions seemed to be to use the Start Counter, Pair Spectrometer, or Tagger times as reference, if possible. The trigger time has too much jitter and is not precise enough to use as a reference.
  • The fADCs do have good timing capabilities, but we would like to be able to commission the TDCs this fall.
  • Elton will gather opinions for a discussion during the Collaboration Meeting.,

Simulations

  • Simon has updated the commissioning simulations with an extended model of the beamline geometry and an extended target region, including the plastic beampipe cap and the air the photon beam will have to pass through.
  • Simon and Sean have been looking at detector rates.

Data Monitoring

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