March 12, 2014 Calibration

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Meeting Time and Place

Wednesday March 12, 2013 at 11:00 AM. At Jefferson Lab, the meeting will be held in F326


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


Attending: Sean, Amiran (NU); Mark, Simon, Eugene, Beni, David L. (JLab); Eric (FIU)

  1. Tracking
    • Sean and Naomi are working on getting various Garfield tables into the CCDB with useful metadata for use in calibrations.
    • Simon mentioned that valgrind has a module called "helgrind" that is useful for debugging problems with threads.
  2. Other systems
    • Eric has been working on the simulation code for the start counter, and is developing methods to extract the attenuation coefficients and timewalk corrections. He hopes to have initial results at the next meeting.
  3. Simulations and Calibrations
    • Sean showed some updated generator level rates for various decay channels, assuming a rate of 10^6 photons/second and electron beam energies of 6 and 10 GeV. The main effect of the different beam energy is to change the overall interaction rate.
    • These results were calculated with the standard hydrogen target. Eugene mentioned that the current plan for the commissioning target is a 2 mm plastic target (CH2?) that can be moved around in order to have a more well-defined vertex for calibrating the drift chambers. The protons generated by this target will make it difficult to accurately reconstruct full events, and we will have to rely on inclusively reconstructed particles, like the omega.
    • Eugene said that a rate of 10^7 photons/s is possible during commissioning. We will also be able to try different amorphous radiators.
    • An (arbitrary) cut on the momentum of the decay particles of >500 MeV was made. This affects the event rates with the lower beam energy more, but is too strict and should be loosened.
    • Sean will revise these results and he and Amiran will start looking at reconstructed events.