April 20, 2016 Calibration

From GlueXWiki
Jump to: navigation, search

GlueX Calibration Meeting
Wednesday, April 20, 2016
11:00 am, EST
JLab: CEBAF Center, F326

Communication Information

Remote Connection

You can connect using BlueJeans using the meeting number 630 804 895 .       (Click "Expand" to the right for more details -->):

  1. Make sure you have created a BlueJeans account via your JLab CUE account using this link:

  2. Meeting ID: 630804895
    • (you may need to type this in, depending how you connect)

  3. If connecting via Web Browser: click this link (no passcode is needed):

  4. If connecting via iOS or Android App:
    • Use your JLab e-mail address to log in and then enter the meeting ID given above to join the meeting

  5. If connecting via Phone: Dial one of the following numbers and then enter the meeting ID above and hit "#" or "##"

  6. If connecting via Polycom unit:
    • Dial or bjn.vc
    • Enter meeting ID above
    • Use *4 to unmute


Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2016 on the JLab CUE. This directory is accessible from the web at https://halldweb.jlab.org/talks/2016/ .


  1. Announcements
  2. Collaboration Meeting
  3. Data Production Planning
  4. Subdetector Reports
    • Resolution & Efficiency updates
  5. Calibration Tasks
  6. Simulations
  7. AOB


Attending: Sean (NU); Simon, Alex B., Paul, Beni, Nathan, Mark I., Eugene, Elton, Justin (JLab); Curtis, Naomi, Mike S. (CMU)

  1. Announcements
    • Online occupancy plots are being regularly generated and are viewable from the offline web page as well. A convenient daily reminder email list has been set up as well.
    • Paul has produced a detailed reference document about Locking in JANA. Summer homework is to improve plugin lock behavior, especially in regard to loading JANA objects inside of locks. Sean rearranged some of Mahmoud's code which yielded a factor ~2 speedup.
    • The last set of calibration jobs, from last week, is nearly finished. Sean will refrain from submitting more jobs to yield more time to the current monitoring run.
  2. The Collaboration Meeting is coming up in a few weeks.
  3. Sean, Paul, and Justin had discussed plans for doing a full reconstruction run over all the data taken this running period. Sean put together a list of to-do items for this processing, and it was discussed. It is expected to take roughly a month to process on the farm. The aim is to produce physics results for DNP in Sept., so a preliminary deadline for these items was set for May 31st.
    • Requirements for flux calculations were also discussed. One solution would be to have standard per-run fluxes calculated by an expert and stored in the RCDB. These results could be checked by analyzers by looking at PS trigger skims or by looking at reconstructed objects. The flux could also be calculated using rates of reconstructed physics objects. Sean suggested that the discussion could continue more offline and concrete proposals be presented at the next meeting.
  4. Subdetector Reports
    • FCAL - Adesh is busy replacing bases in the hall. He has been updating the CCDB with new gain calibrations.
    • BCAL - The updated clusterizer has been added to sim-recon and is being used in the current monitoring launch. Updating the timing calibrations is the next task.
    • Tracking - Mike is working on the problem of the larger CDC residuals. The tracking FOM distribution peaks near 1, so something fishy is going on, but the cause is not obvious. Could it be issues with the multiple scattering? Alignment? Kalman filter weirdness? He is working on a more detailed plugin to look at these issues on a per-straw basis. Mike and Simon both see similar issues with FDC tracking as well, so these need to be understood. Simon is also finalizing his CDC shifts based on vertex imaging.
    • TOF - Beni is ironing out the final fixes to his calibration procedures. Running all the calibration jobs on the farm will take ~3 days. He's also changing the procedure to require a constant effective speed for each paddle, instead of a run-dependent value.
    • SC - Sean has been working with Mahmoud on various tasks. The updated propagation time corrections were added to sim-recon and CCDB on Friday. Next is efficiencies and matching in the nose region. The time resolutions in simulation are still larger than expected (~350 ps compared to 300 ps expected).
    • TAGH - Nathan's todo list: Update timewalks, implement merging of hits where one electron hits multiple counters.
    • TPOL - Sascha added new PS energy calibrations to CCDB last week. Nathan looked at the effect of these new calibrations in the collimator scan data. The tagger vs. PS energies have a ~40 MeV offset with a ~60 MeV width, which is ~an order of magnitude smaller energy width than was previously seen, so a big improvement. He is now reanalyzing the TPOL data.
    • PS - Alex showed some slides on his PS studies with these new calibrations. The results look much better, with no asymmetry corrections between the arms needed.
    • TAGM - Alex's todo list: Update timewalks, determine software thresholds.
  5. Calibration Tasks
    • Sean is coordinating the update of mcsmear parameters with the various detector groups.
  6. AOB