General Meeting Summary 10/5/17

NPS SUBSYSTEM UPDATES

• PMTs and HV Dividers

• New PMTs were delivered with slightly different sockets - requires machining (or, if doesn't work get back to Hamamatsu)

• 100 of the new PMTs were given to Hall D for assembly and tests

• 1-2 new PMTs ready to be shipped to IPN-Orsay for assembly and tests

• Assembly drawings of PMT+crystal module from HyCal are being collected - action item: get the original drawings from designers

• similar to HMS calorimeter, but dimensions different and PbWO4 more fragile
• found that in actual HyCal PMTs were NOT glued to crystal (that was only done for prototype modules)

• OU got a quote for HV divider components - checking the details, if all looks ok, will go ahead with the full procurement

• PbWO4 Crystals

• Discussion of visual inspection and dimension measurements with caliper of box#3 (10 crystals) of the first set of 160 SICCAS crystals

• Visual inspection shows that about half of these crystals have bubbles and/or chipped edges - according to data the company sent, this does not affect optical properties
• Action item: post the data the company sent

• Discussion about alternative measurement methods to make nondestructive measurement of crystal dimensions that is safer (and potentially faster) than measuring with caliper

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