Aug 29, 2019

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Agenda:

Systematics Discussion: Don [1]

Connection details:

Meeting URL https://bluejeans.com/388466836

Meeting ID 388 466 836

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Minutes Attendees: Paul S., Bill H., Don J., Eric K., Dave G, Simona M., Sanghwa P.

We went over some of the recent results discussing the two main issues: IN/OUT difference and 4 micron vs 10 micron foil difference

• Is the IN/OUT difference real? Dave G. said he has never before seen a persistent IN/OUT difference like we are seeing. It seems wise to request a precision Mott measurement at the 0.3% level which will take about 3 hours. Sanghwa suggested that we might be able to fit it in without too much argument from Hall B after the next Wein flip.

• Don proposed the plan below (with suggested revisions) for the next measurement. There was no opposition although Simona proposed a few changes. She believes the measurements can be done in less time than allotted and requests 1. that we do a saturation measurement on both 4 and 10 micron regardless 2. proposes turning up the current on the 10 micron foil to 1.5 muA in the rate scan (step 5) 3. Add a polarization measurement on 4 micron foil at a new position like 2mm off center. 4. Add a measurement with 8 PMTs on the 10 micron foil. Don and Dave supported the 8 PMT idea in principle but there was rather strong pushback from Paul since he does not think it will be interpretable especially without a special Q1 and dipole scan.

Run plan

1. Setup = 3 hr
2. Quad and dipole scans = 2.5 hr
3. PREX polarization measurements @ 4T = 6.5 hr
   • In and Out on Cu = 1.7 hours
   • In and Out on 4 micron = 2.5 hours
   • Quick Q1 rate scan = 1 hour
   • In and Out on 10 micron = 1.8 hours
4. Saturation verification @ 3.5 T = 2.5 - 5 hr
   • In and Out on 4 micron = 2.5 hours
   • Consistent? = Move to step 5.
   • Inconsistent? In and Out on 10 micron @3.5T= 1.8 hours OR In and Out on 4 micron @ 3T = 2
5. Rate scan = 1 hr (optional if haven't already diagnosed 4/10 foil difference to rule out rate dependence)
   • 2 extra points at 1 1.5 muA and 0.3 muA on 10 micron = 1 hour
6. Additional measurements time permitting
   • In and Out on 4 micron at different position (2mm offset)
   • 8 PMT measurement on 10 micron = 1hr
7. Backout = 1.2 hours