General Meeting Summary 6/7/17

DETECTORS AT JLAB (Arthur, Vardan, TH)

• SHMS Aerogel Cherenkov - exchanged aerogel tray from aerogel with refractive index n=1.015 (SP-15) to n=1.011 (SP-11) - a few pictures of the procedure.

• Discussion of procedure - small modifications from nominal - need to update the manual

• SP-11 tray was covered and lifted into the SHMS detector enclosure with the overhead crane
• Plastic cover was installed on the Heavy Gas Cherenkov window
• SP-15 tray was removed - some trouble with O-ring and tape being stuck on the tray, placed on the SHMS floor and covered with a plastic cover
• O-ring and new tape were installed on the diffusion box
• Aluminum cover from SP-11 tray was installed on SP-15 tray (plastic cover was installed on SP-11) and tray was moved out of the enclosure with overhead crane
• SP-11 tray was lifted to 18 degree angle, lifted up to and bolted onto diffusion box

• Discussion of (time) requirements to exchange aerogel trays - about 1 day

• Removal of SHMS top concrete blocks takes about 2 hours (re-installation takes also 2 hours)
• Tray exchange takes 2-3 hours
• Safety: only trained/qualified personnel are allowed in the SHMS enclosure during tray exchange

• Extra aerogel trays (SP-15, SP-20, SP-30) are now stored in the ESB
• Gas flow system discussion - Hall C agrees to provide

• input port on bottom, output on top (see this picture for location of hole)
• in addition, Hall C has been installing a He monitoring system in the SHMS hut

• Action items:

• Final check on detector, e.g. for light leaks (protect PMTs!)
• Take cosmic data

• HMS Aerogel Cherenkov - no success removing dead PMTs from cylinders so far

• Signal from PMTs do not show after pulsing - just noise
• Taking one of the PMTs with cylinder to CUA to try to remove

PION AND KAON STRUCTURE FUNCTIONS (Richard, Andres, TH)

• Discussion of PIEIC2017 Workshop at Argonne National Lab

• Much progress in theory towards origin of mass and role of pions and kaons in it, experimental tools are available and work is ongoing to demonstrate feasibility of studies with EIC - a few slides of theory and simulations
• Based on initial simulations looks like measurements can be done - good kinematic coverage and reasonable statistics allow for fine binning - a few slides by Andres on the simulation procedure
• Measurements have high potential, will have a substantial impact on requirements of forward EIC detector design
• Future simulation work: include detector resolutions - start with those from DESY

PBWO4 STUDIES AT CUA (Marco, Richard)

• Characterized the 5th cycle CRYTURII crystal (results)

• transmittance and radiation resistance look good, light yield is on the low side

• to check consistency of setup, all measurements are checked against the reference crystal J24

• Next: check systematics, crystal-to-crystal variation

DETECTORS AT CERN (Rishabh, Rachel)

• Comparison of CMS tracker material budget (eta vs fractional Radiation length) of 2015 Geometry( phase 0) and 2017 (phase 1) ongoing - a few plots of the current status

• Also work ongoing on timing of detector, have stable beams and working on optimization of data taking

NEXT MEETING: WEDNESDAY 14 JUNE at 10:00 AM (EDT)