December 2, 2015 Calibration

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GlueX Calibration Meeting
Wednesday, December 2, 2015
11:00 am, EST
JLab: CEBAF Center, F326

Communication Information

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Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2015 on the JLab CUE. This directory is accessible from the web at .

Calibration Tasks


  1. Announcements
  2. Calibration Tasks
    • Calibration Challenge update:
      • Current status: jobs run through pass 2 (of 3)
      • New additions: BCAL gains, PS timing, PSC timewalks, SC timewalks, TAGH timewalks
      • Upcoming: TAGM timewalk, FCAL gains & pedestals, PS energy calibration
      • Documentation: RF Calibration, PSC TW Calibration
      • More validation needed
  3. Subdetector Reports
  4. Future Simulations
    • Future Run Numbers & Magnetic Fields
  5. AOB


Attending: Sean (NU); Simon, Beni, Mark I., Adesh, Alex B., Nathan, Justin (JLab); Curtis, Mike S., WIll M., Naomi (CMU); Mahmoud (FIU)

  1. Announcements
    • Beam is expected to be delivered to Hall D next week.
  2. Calibration Tasks
    • Sean gave an update on the calibration challenge. He has been debugging batch jobs, and has made it through pass 2 out of 3 without jobs failing. There have been some obscure errors that have shown up, but so far only 1 job has had an error that he has been unable to reproduce. First results are planned to be reported next week.
    • The list of recently added plugins is given in the agenda - a few more are planned to be included.
    • Sean requested that all calibration plugins have at least some wiki documentation added by the end of the year, and showed two examples.
    • He is working on some reporting tools enabled by a lower-level API explained to him by Dmitry. Some other CCDB issues are being addressed.
      • Mark said that he is working with Dmitry to get more extensive CCDB documentation on the wiki hosted in the github repository for CCDB. The python interface to this lower level API is explained here. Dmitry, Sean, and Mark have been using the issue tracking feature of github to tackle the bugs/features that have come up. There was some discussion about how these could be used for other Hall D software projects.
      • Beni has written some C++ code using these APIs, and will provide some examples for others that are interested.
  3. Subdetector Reports
    • FCAL - Adesh has put in updated pedestals (same values for mode 7+8 data) and gains (different for mode 7,8) for Spring 2015 data. The difference between the gains for mode 7 and 8 data is understood to be due to a mismatch between the algorithm used by the firmware in mode 7 and the emulation in sim-recon for mode 8. Addressing this difference requires the major rewrite of the emulation code that is in progress. Adesh tried modifying the configuration of the emulation in a private version of sim-recon, but did not find an improvement in the resolution, so the larger FCAL resolution is still not understood. The hardware gain balancing has been done, default software gains of 1 will be uploaded to the CCDB for the current run period.
    • BCAL - No news.
    • CDC - Constants to correct for wire sag have been added to the CCDB. Mike is still checking his new drift time constants before adding these to CCDB/sim-recon. He has derived these from beam data, so the calibration codes can be incorporated to the calibration challenge.
    • FDC - Simon mentioned that Lubomir has found improvement in strip/wire resolutions by improving the fitting procedure. Simon is still working on incorporating this code into sim-recon tracking. He thinks this work can be done by the Feb. 2016 run.
    • TOF - Beni wrote some code to perform a fine-tuning on the time offsets between different TDC channels on the same chip. This involves looking at the least-significant bits of the times, and takes several thousands of hits - this is slow with cosmic data. Currently his code is doing a brute-force calibration of the different parameters - there is a most sophisticated algorithm which is supposed to work, but he wasn't able to get it to work yet.
    • Start Counter - Mahmoud is in the process of converting the propogation time corrections to work in the calibration challenge framework.
    • TAGH - Nathan cleaned up his timewalk calibration code and added it to sim-recon. He is doing some final checks to see if there are any lingering time offset issues before committing the new constants.
    • TAGM - Alex is finishing off his PS energy calibration code, and testing it with Nathan's PS time calibration code. He is running some final checks before adding in his code.
  4. Future Simulations
    • Mark reported that 3 out of 10 jobs that he ran over the weekend failed, but were fine after rerunning. He is currently running 90 jobs. He will review emails, etc. to figure out what else needs to be fixed before we do a full production. The only known outstanding problem is that there appears to be a timing shift in the BCAL - the beta of high momentum tracks seems to not quite reach 1. Sean will take a closer look at this.
    • Sean suggested that we fix the run number for the beginning of the Feb. 2016 to a particular value. Since calibrations in simulation are supposed to track those of data, that would allow us to set simulation conditions ahead of time, without using some "special" run numbers. This would be a one-time change. There was a general feeling that this was not a bad idea, and we would discuss the details in next week's Offline Software meeting.