JEF meeting, March 25, 2022
Meeting time and location
- 9:30 am EST (JLab time) remote only
- Zoom meeting ID: 161 050 9142 Passcode: 004965
- Preparation for mass production of FCAL2 modules -- Sasha
- PMT selection
- Olga checked PMT diameter of 360 newly received PMTs. Many PMTs from the last shipment (210 pcs) are tight (about 40%)
- These PMTs were exchanged with NPS. 40 more PMTs were selected with Vlad and are ready for exchange when purchase spares.
- Total number of PMTs: ordered and received: 1510, 140 installed on CCAL.
- Need to order about 100 (?) spare modules.
- These PMTs are also used in different test setups
- Production of Silicon cookies
- DSG group: continue preshaping ESR reflectors (18 a day), and wrapping crystals (about 6 a day)
- Chris A. is brazing brass straps, Bobby is honing PMT housings.
- Igal is cutting Tedlar and ESR foils
- PMT selection
- Module fabrication -- Sasha
- Light Monitoring System March 25 LMS update -- Arshak
- COMCAL tests, TAC running, etc. -- Sasha
- Discussion at the CPP engineering meeting regarding using assembled modules (an array of 3x3) as a TAC) during the CPP run
- Data analysis
Attendees: Bill, Zisis, Arshak, Tegan, Igal, Jon, Liping, Olga, Phil, Jane, Sasha, S.T.
- Arshak gave an update on the LMS
- Illuminated a small plexiglas plate with light from 2 blue LEDs from 10 fibers injected on one side and looked at the light uniformity across the plate
- Saw noticeable gradient in the measured light the further the probe was from the fibers, as expected, but relatively uniform in a column near the center, and an increase in the column furthest from the source due to reflection
- Plan to illuminate the plate with additional fibers on the opposite side of the current set of fibers
- Plan to build a larger scale prototype
- Sasha reported plan to purchase 100 PMT spares -- plan to ask Hamamatsu to pre-select for diameter given the relatively large fraction of tubes from a recent batch that were too wide
- Trades with NPS to get their smaller diameter PMTs
- Also plan to order 200 new sockets
- Fabrication of modules continues -- now up to 209
- Plan to build 28(?) new PMT dividers by summer, all dividers for FCAL-II ordered by fall?
- We had some discussion about the state of the single-block TAC and the possibility of building a 3x3 array using lead tungstate crystals
- Test setup downstream of FCAL?
- Lab has switched to MedCon-3: Sasha will check what this means for students in the summer (Phil potentially has students he could send but needs to know soon)
- Sasha to meet with Tim regarding cables/patch panels for FCAL-II