November 19, 2014 Calibration

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GlueX Calibration Meeting
Wednesday, October 22, 2014
11:00 am, EDT
JLab: CEBAF Center, F326

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  1. Announcements
  2. Status Update
  3. Calibration status/updates
    1. FCAL
    2. BCAL - email from Zisis
    3. CDC
    4. FDC
    5. TOF
    6. Start Counter - ST CCDB Update
  4. Fall 2014 Commissioning Simulations updates
  5. Data Monitoring
    1. Commissioning Software
    2. Run Browser, Plot Browser, and Time Series webpages
    3. Discussion of results (Kei)
  6. AOB


Attending: Sean (NU); Kei, Simon, Lubomir, Mark I., Justin, Nathan S., Will McG., Naomi, Mike S. (JLab); Paul (CMU); Eric (FIU)

Status Updates

The target conditions are being tracked as a function of run, and in the process a problem where the run number wasn't always being saved in the EVIO files was found and fixed.

We then reviewed the status of various subdetectors.


We reviewed an email from Zisis. Mark D. extracted the attenuation lengths. Will M. is working on pi0 reconstruction. Tegan is looking at the thresholds in various runs. Andrei is extracting the fADC to physical unit calibration using cosmic data.

No pi0 peaks are found yet. The beam data studies are statistically limited.


Lubomir reported that last night they took several hours of data with the solenoid turned off. The data looked to be of good quality, with many reconstructed tracks. This data is allowing him to take a preliminary look at the alignment, e.g. the rotations of the different packages. Vlad has been looking at the cathode strip calibration using cosmic data, and he is starting to use the same technique with the new beam data. Preliminary results are encouraging.

The TDC readout for the wires is still a problem, which is limiting the obtainable time resultion, and hindering the calibration of the time-to-distance functions.

Simon has been analyzing the data and has posted several plots to the logbook. He is looking at matching tracks to other detectors. Matching to the start counter and FCAL is working well, and he has been able to image the start counter. For the FCAL, right now he can only match to hits not clusters. He is not able to match to the TOF hit positions.

Having a BCAL trigger would be useful for getting tracks that illuminate more of the FDC. Having tracks from the active target is useful as well. Simon's made several plots of track vertex location, and sees what looks like some tracks coming from active target.

10-20% of the tracks look like they come from the beam halo or interactions in the air.


Naomi and Mike said that they have taken data at three high voltage settings as part of a scan to find the best high voltage set point.

Simon has found that the quality of the reconstructed tracks with the field off is problematic and this is leading to problems matching to BCAL hits. The matching with the field on is fine. He is looking into this.

  1. Calibration status/updates
    1. FCAL
    2. BCAL - email from Zisis
    3. CDC
    4. FDC
    5. TOF
    6. Start Counter - ST CCDB Update
  2. Fall 2014 Commissioning Simulations updates
  3. Data Monitoring