Fall 2019 Commissioning Meetings

Meeting Information

GlueX DIRC Meeting
Tuesdays and Thursdays, December 3-19 + January 14
10:00 am, EDT
Hall D Counting House

Connection Using Bluejeans

1. To join via Polycom room system go to the IP Address: 199.48.152.152 (bjn.vc) and enter the meeting ID: 846453895.
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Useful Links:

• Run Coordination Meetings:Fall2019 Run
• DIRC Fall 2019 Run Plan

Tuesday, January 14

• Spring 2019 DIRC Commissioning Analysis
• Fall 2019 Commissioning Analysis
• Initial production of Fall 2019 data available:
  • dirc_tree files: /cache/halld/detectors/DIRC/RunPeriod-2019-11/dirc_monitoring/ver01/hists/merged/
  • DIRC LED skims: /cache/halld/RunPeriod-2019-11/calib/ver01/DIRC-LED/
  • REST files: /cache/halld/detectors/DIRC/RunPeriod-2019-11/dirc_monitoring/ver01/REST/
• New simulation samples (50M ρ and φ events each):
  • Spring 2019 (previous commissioning, South Box only): producing dirc_tree files now ... slowly
  • Fall 2019 (new mirror box geometry): running hdgeant4, etc. today... dirc_tree files later this week
• Current analysis updates
  • FastDIRC (Yunjie)
• Upcoming analysis plans

Thursday, December 19

• Reconstruction of runs 70817-71073 almost complete (~8 billion of the 10 billion triggers collected so far):
  • REST, histogram and tree files appearing at: /volatile/halld/home/gxproj7/RunPeriod-2019-11/dirc_monitoring/ver00
  • Plan for data production over downtime
• Summary of production datasets
• LED analysis:
  • Time over threshold analysis - Gain_eq (Andrew)
  • Correlations between fibers and hit times (Bill)
  • LED analyses [2] (Ahmed)

• GEM update and analysis plans discussion
• High rate studies:
  • DAQ performance sufficient at 400 nA (nominal GlueX-II conditions)
  • Plan to continue this overnight for more experience before January startup
• Plans for shutdown:
  • LED runs for HV/threshold scans on Friday after beam down
  • LV and HV off over break, but no mechanical changes planned
• Investigation of North OB in January:
  • Proposal to drain North OB, inspect Bar Box 0 optical coupling to mirror box (misalignment?), inspect mirrors
  • Beam could be back as early as January 7, so we can likely only observe the situation and seal things back up.

Tuesday, December 17

• Initial data analyses (early runs 70817-70849):
  • Standard halld_recon LUT: [3]
  • FastDIRC: [4]
  • LED analyses north box [5]
• Total statistics around ~6 billion triggers so far, should get close to statistics we had last Spring (~10 billion total)
• Upcoming plans:
  • Remaining GEM data with focused FCAL trigger
  • Additional DIRC threshold/gain/HV settings:
  • High rate tests: paths to eliminate DIRC as bottleneck

Thursday, December 12

• Initial data (70817-70849) reconstruction complete:
  • REST, histogram and tree files appearing at: /volatile/halld/home/gxproj7/RunPeriod-2019-11/dirc_monitoring/ver00
• Waiting for runs 70937+ to be transferred to the /cache/ disk
• VERY preliminary first look with FastDIRC
• Upcoming plans:
  • More GEM data with focused FCAL trigger
  • High rate trigger/DAQ tests, including DIRC (Sasha)
  • CPP test, 1 hr (David)

Tuesday, December 10

• First field-on data Friday evening: Run 70817+
  • Initial issues with timing now resolved and data processing some plots
  • Initial data reconstruction underway:
    • REST, histogram and tree files appearing at: /volatile/halld/home/gxproj7/RunPeriod-2019-11/dirc_monitoring/ver00
• Unfortunate data loss before accelerator vacuum issue: Run 70850-70895: https://logbooks.jlab.org/entry/3750309
• LED Analysis: (Ahmed/Bill/Andrew)
• Upcoming plans:
  • When beam is back continue with nominal conditions: Threshold = pedestal + 100, equalized gains, HV = 1000 V
  • Dedicated runs with GEM detector included with low trigger rate

Thursday, December 5

• Collected straight track data in "beam left" position: see correlations with TRD wire chamber and GEM SRS (APV) modules
  • A couple runs with DIRC included for initial tests (70720 and 70721)
• LED Analysis: (Ahmed/Bill)
• Upcoming plans:
  • Today/tonight: Straight track data in center and right positions by Friday morning.
  • Friday: Ramp solenoid and setup for DIRC commissioning
  • Weekend: DIRC commissioning with full solenoid field!

Tuesday, December 3

• Status update from the Hall
• Plans for straight track data