May 21, 2014 Calibration

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GlueX Calibration Meeting
Wednesday, May 21, 2014
11:00 am, EDT
JLab: CEBAF Center, F326

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  1. Announcements
  2. Status Update
  3. Tracking CDC_B_field
  4. Calorimetry
  5. Other systems
  6. Simulations and Calibrations


Attending: Sean, Amiran (NU); Beni, Simon, Lubomir, Eugene, Mark, Mike S. (Jlab); Curtis, Naomi (CMU)

  1. Status Update
    • As discussed in the Collaboration Meeting, Sean has started to go through the reconstruction code to implement the loading of tables that have already been defined and to identify other hardcoded values that need to be updated or changed to parameters that can be optionally set on the command line. He has finished the first pass through the FCAL and SC, and has done the digi-level constants for the FDC and CDC. He is currently working on the BCAL and TOF. These changes will be committed to SVN as soon as a potential change to the CCDB C++ API is finalized.
    • For the purposes of planning to implement the alignment constants, Sean asked about how the nominal geometry information is currently stored. In the reconstruction code, each of the subdetectors has its own class that handles accessing this information. Some of this information is loaded from HDDS, but a lot of it is hardcoded in, partially because HDDS doesn't contain all the information that is needed for reconstruction. This is not necessarily bad, but best practices for this are something that needs to be discussed in the future.
    • Sean has started keeping a list of the constants that need to be updated in one way or another. He linked to a wiki page with some results-in-progress, which will be updated and organized into a plan.
  2. Tracking
    • Simon has been working on adding in constants to the tracking code, primarily the time-to-distance relation. The form in the CCDB is different than the parameterizations that are currently used, and putting it in the code in a consistent way is an ongoing project.
    • Naomi gave a brief update on her investigations into correcting for the magnetic field. She showed some results from her logbook wiki page, and is almost done looking into the r-dependence of the magnetic field, as suggested by Richard at the Collaboration Meeting. She plans to communicate an appropriate correction function to Simon and put together a brief note documenting this investigation by the next meeting.
    • David L. recently added magnetic field maps for the 1200A and 1500A configurations, for use in the Solenoid_Current_Studies.
    • Lubomir plans to present some results from the FDC cosmic data taken at the EEL at the next calibration meeting.