KPP November 30, 2014

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Meeting Time and Place

The meeting will be on Sunday November 30, 2014 at 4:00pm EDT. No room at Jefferson Lab has been reserved.

Meeting Connections

  1. To join via a Web Browser, go to the page [1]
  2. To join via Polycom room system go to the IP Address: ( and enter the meeting ID: 660743227.
  3. To join via phone, use one of the following numbers and the Conference ID: 660743227.
    • US or Canada: +1 408 740 7256 or
    • US or Canada: +1 888 240 2560
  4. Upon connection all microphones are automatically muted. To unmute your mike on a Polycom or equivalent unit, enter *4. Unmuting on a computer is trivial as there is a microphone button than can be clicked.
  5. More information on connecting to bluejeans is available.


Proposed Key Performance Parameters from November 21, 2014

This section was updated after the meeting on Nov 30

Hall D: “Detector operational: events recorded with a > 2 nA electron beam at > 10 GeV beam energy (5.5 pass)”

Done: all data taking happened with >40 nA 10 GeV electron beam

Expected photon beam rate: Tagger: ~ 620Hz/MeV at the endpoint, at 50nA, 0.2e-4 RL. About 20% should pass through the 5mm collimator hole. Very preliminary PS measurements are about 50% off.

  1. Detector running for ~one shift recording data from all subsystems.
    • ~8h data taking on Nov 23 20:00 - Nov 24 8:00 at 50 nA, 0.2e-4 RL, FCAL trigger, solenoid at 1200A
    • ~8h data taking on Nov 25 22:00 - Nov 24 6:00 at 100 nA, 1e-4 RL, BCAL trigger, solenoid at 1200A
    • Done
  2. Snapshots of beam status screens and accelerator Elog entries demonstrating the electron beam current and energy.
    • Log Entry 3309351 Snapshot with 100nA, 1e-4 RL. Show
    • Log Entry 3307724 Snapshot with 45nA. 0.2e-4 RL
    • Done The beam energy can be derived from the tagger magnet field (1.5T for 12 GeV): 1.26T/1.50T*12GeV=10.08GeV
  3. Plots showing relative timing (coincidence) of the signals in TAGx, TOF, BCAL, FCAL, ST, PS (with TAGx).
    • Log Entry 3309600 TDC timing of FDC, BCAL, ST, TOF, TAGH, TAGM and the FADC timing of TAGH, TAGM for the FCAL-triggered data at low luminosity and the BCAL-triggered data at high (x30) luminosity. The TAGH/M FADC signals are in the readout window, while the TDC signals are not (further trigger/latency tuning required)
    • Log Entry 3308810 Similar to Log 3309600 for the FCAL trigger, in log scale
    • Log Entry 3308027 TAGH/M timing with the PS trigger
    • Done - TAGx TDC signals are out of the readout window yet
  4. Event displays showing correlations of particle hits in the CDC, FDC, ST, TOF, BCAL, FCAL.
  5. Plots of reconstructed particle trajectories showing target position.
  6. Particle identification plots using signals from calorimetry and timing detectors (e.g. FCAL, BCAL, TOF).
    • GlueX-Doc-2609 Local copy. p/π identification by dE/dx in CDC and FDC.
    • GlueX-Doc-2612 Local copy. p/π identification by TOF
    • GlueX-Doc-2610 Local copy π0 reconstruction in FCAL. The initial calibration was off by a factor of 2, indicated both by the π0 bump and by the E/p ratio for electrons/positrons
    • GlueX-Doc-2611 Local copy More details on π0 reconstruction in FCAL.
    • Local copy. π0 reconstruction in FCAL - another analysis. The MIP signal in FCAL is more pronounced. The energy scale is different from the first analysis (this is due to an HV factor that Matt applied by hand that David didn't know about, so different overall calibrations).
    • Local copy. π0 reconstruction in FCAL/BCAL from Will
    • Done? There are several PID signals: p/π in both drift chamber packages, electrons in the Forward Calorimeter and π0 reconstruction in the FCAL. Detector calibration will be needed to improve all of these signals.

Path forward and goals for running in December 2014

  1. Trigger/DAQ time adjustment to readout the tagger TDCs
  2. Reduce the background in the PS (secondary collimator installation?)
  3. TAGH/M time calibration with the PS trigger (4h data taking), PS calibration, measuring the beam flux
  4. Trigger setting for BCAL+FCAL, FCAL*ST and other combinations, mix the PS trigger with the others (2 shifts)
  5. DAQ: improve the speed to at least 1kHz with <20% of dead time (full readout of compressed readout)
  6. Data taking for FCAL calibration with pi0s (at least 4 shifts)