General Meeting Summary 8/23/17

DETECTORS AT JLAB (Arthur, Richard)

• SHMS Aerogel detector

• broken bolts on top fixed with help of Walter's team - uses same holes as before, drilled/tapped and installed new hex bolt, anticipate this to be a recurring issue due to materials difference (stainless steel bolt and aluminum box)
• still need to take cosmic data to check if light leak fixed - ideally would like scintillators and drift chambers on during this test
• Trays SP-20, SP-15 and SP-11 are stored in ESB building in roped off area near HKS equipment

• Neutral Particle Spectrometer

• 100 PMTs arrived (Pic1, Pic2, Pic3, Pic4)

• Diameter is less than 19.2 mm as requested, result from 4 randomly selected PMTs: 19.0 +-0.2 mm - see this picture
• Labels (est. thickness 50-100 um) are not glued to PMT body as requested to maximize space for shielding - see picture

• Crystal arrival - latest update: delivery of all 460 by end of September

• Magnet main coil shipment delayed until end of November (A few pictures: Pic1, Pic2)

• HMS Aerogel Detector

• Testing method to remove Bates PMTs without breaking them
• Working on PMT scanning setup to test Bates PMTs once installed in the cylinders

PBWO4 STUDIES AT CUA (Richard, Andres)

• Crystal drawing prototype

• design drawings including thermal design complete

• indicate existing holes on furnace sides
• add additional holes needed on furnace top and sides
• indicate furnace heating elements for interference checks

• mechanical setup ready and calibrated - link the results

• heating elements have been installed

• thermal profile simulation - initial results available

• Crystal testing

• all systems ready for crystal testing

• commissioning of new pulse generator ongoing

• possible incompatibility between TTL output and electronics - check out manual for input pulse requirements

• reflector optimization studies ongoing

DATA ANALYSES AND SIMULATIONS (Salina, Dannie)

• Progress with DVCS-3 deadtime studies

• need to resolve issue of current dependence of DVCS coda events vs. DIS events

• investigate calo part (bottom circuit on page 2) vs. HRS singles (top part of same diagram)

• Note that HRS has delay of ~1 usec to form trigger, while ARS (calo) takes about 600 ns for signal

• Pion and Kaon Structure functions

• Resolved several issues in uncertainty calculation, e.g. dependence of mean on specific binning and unit inconsistencies

• Results look reasonable and encouraging for structure function studies!

• may want to check consistency with Kijun's calculation of uncertainties

• Work on detector simulations ongoing

OTHER

• Vladimir still waiting for visa - hopefully after 1 Sept

NEXT MEETING: WED 30 AUGUST at 10:00 AM (EDT)