General Meeting Summary 11/2/16

PION PROJECTIONS FOR KAON EXPERIMENT

• Discussion of Salina's presentation - overall looks very promising for early pion form factor extractions

• Clarify what high and low sigma means - this requires the cross section formula on page 5. It shows that one needs knowledge of the epsilon dependence of the cross section to isolate the longitudinal contribution. The latter is the piece that will give us the pion form factor. Simple solution to address this: exchange order of slides 4/5
• Correct the estimated uncertainty on Fpi. It's currently overestimated as the normalization error in the cross section is amplified by delta epsilon (see the formula on the slide). Normalization error is the same at both low and high energies, so no amplification needed
• Investigate how much additional beam time would be needed to achieve full coverage in the azimuthal (phi) angle at low beam energies

DETECTOR UPDATES

• Discussion about APD readout for PWO (Andres)

• Borrowing 2 APDs and 5 pre-amplifiers from JLAB Hall B HPS experiment. Contact person is Stepan Stepanyan.
• APDs are from Hamamatsu and about 1cm x 1cm
• HV setting: 383 V at 18 deg C
• LV setting: 5 V - positive or negative?
• output of pre-amplifier goes directly to ADC
• Action Item: setup APDs in CUA lab and test

• Discussion about PbWO4 crystal characterization plans (Richard, Rishabh)

• 'Action Item: resolve issue with different light yields measured before and during summer 2016

• PMT magnetic shielding (Arthur)

• Discussion about fiber/LED attachment to setup - at least two options:

• fiber connector attached to small square in picture
• gluing fiber into fitted hole in small square

• General procedure: Start with mu-metal (100 um) 3 layers around PMT and check influence of magnetic field for different orientations of PMT with respect to field
• Action Items:

• Signal test
• Magnetic field test - aim for results by next NPS meeting (Thur. 10 November)

• Aerogel Detector

• First layer of SP-11 aerogel was installed in tray - no tiles broken! Tile sizes vary just enough that cutting may be required for the next layers
• Action Items:

• Continue with SP-11 aerogel installation
• Check on SP-15 tray in SHMS in Hall C - work on detectors surrounding ours should be done now

OTHER

• Data for pion experiment in 2018? - checking available beam energies

• Travel plans for January/February (Hall A/C meetings, NPS collaboration meeting, High-Intensity Photon sources workshop)