General Meeting Summary 12/21/16

GLUEX (Greg)

• Transmittance measurements of cookies completed at CUA - consistent with previous measurements at JLab. Conclusion is that making cookies at a company is more efficient than making them at the university
• Next test for feedback to company is radiation hardness with Xrays
• DIRC focal plane measurements (addressing lens aberratiopns) ongoing at ODU - more on this next time
• Transportation of BaBar boxes: test of a transportation concept will happen in mid-January

NPS: ALTERNATIVE PBWO4 CRYSTAL READOUT (Andres)

• Adapted HPS prototype for measuring light yield with APD - got signals, but interpretation difficult without further information on light source (e.g., stability of LED, optimal voltage range).
• Next: construct a setup based on the one from HPS, but with flexibility to have: 1) no crystal, 2) option to exchange APD/PMT for readout

• Calibration of setup requires a calibrated light source and SEP range (if noise level too high, it will not be visible).
• to find SEP, reduce the light intensity step-by-step by installing a filter after LED - if the peak observed is the SEP, it will first change only in amplitude as intensity is increased, and then as get more photoelectrons move to higher ADC channels
• for checking capability of setup and assuming Gaussian distributions, ~1000 events are sufficient

CUA DETECTORS AT JLAB (Arthur, Hamlet, Vardan)

• Aerogel detector:

• cover for SP-11 tray likely done this week
• tray exchange in early 2017
• SHMS software and electronics development/installation in progress - not yet ready
• Action Item: develop commissioning plan for scheduled beam tests in March 2017 ff (two major components: 1) same techniques as for cosmic tests already done (trigger 3/4, different momenta, scintillator all or subset), 2) measurement with full tracking for studies of: effective area, position/momentum dependence, thresholds, impact of backgrounds

• NPS PMT shielding concept

• investigating tests with additional mu metal shielding
• studies of if axial shielding is needed ongoing - if needed, this would be a major design change. Check the magnetic field maps - see NPS meeting agenda/summaries in Wiki
• Action Item: repeat all measurements in January 2017

NEXT MEETING: WED 4 JANUARY 10 AM( (EST)