General Meeting Summary 1/4/18

SUBSYSTEM UPDATES

MAGNET (Bogdan)

• Magnet main coil on the way from New Zealand - anticipated arrival at end of January

• Magnet yoke on schedule for delivery end of January or beginning of February

• Many parts are finished and will be going for painting. Still have to finish machine a few items, mostly the parts from the sawed plates. They are all ground and are not expected to take long to machine. A few of the rough machined items are out for heat treat. The painting is delayed because of the extreme cold right now.
• Pictures of the yoke parts: Pic1, Pic2, Pic3

• A sketch of the new test lab space for NPS

• same dimensions, just in a different location

HV DIVIDERS (Julie)

• Order was placed for 1200 dividers, anticipate 30 day delivery, assembly of a few hundred could be done by summer
• Need sockets for full assembly

• currently have ~200 PMTs and sockets at JLab (some have been machined from larger size, but all should be ok)
• option to procure all sockets this year to finalize full assemblies by next year fall

FRAME (Carlos)

• Planning to present design options at the collaboration meeting and to discuss possible optimizations. IPNO engineer/designer will also meet with Mike Fowler.

CRYSTALS (Carlos, Rong, Vladimir, TH)

• Granite table ready for dimension measurements at JLab

• IPNO setting up for crystal characterization measurements, carried out tests at Giessen U. for inter-laboratory comparison - data analysis ongoing

• Microscopy and chemical composition analysis were carried out for 12 crystals at CUA.

• chemical composition determined with XRF, statistical analysis suggests that both, stoichiometry and addition of other elements have an impact on optical properties, more detailed analysis ongoing

• Optical measurements continuing at CUA

PMTs (Vladimir, A. Somov)

• PMT characterization setup at JLab - fixed light leaks of dark box in the process

• 65 PMTs were tested, all with the same divider

• HV scan, measured amplitudes - looks good at first glance
• HV scan at fixed amplitude

• Planning to write report on all measurements and post in Wiki

TIMELIKE COMPTON SCATTERING WITH TRANSVERSE TARGET AND RUN GROUP IDEAS

• Discussion of analytical TCS rate estimate with CPS based on Jan2017 simulations with NPS only

• Looks promising and competitive with other experiments - need to check rates in more detail now

• Discussion of SSA in quasi-real photon production off transverse target

• Discussion of tests of reaction mechanism in exclusive pion production

• Action Item: Try to work out count estimate with NPS+CPS setup and what asymmetry can actually be achieved. Can keep the same generator for that

NEXT MEETING: TUESDAY 23 JANUARY 2018 AT JLAB