Meeting time and location

Agenda

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
  - Received three fixtures to prepare silicon cookies (42 dishes in each fixture); Olga will take two fixtures to the GWU.
  - Olga produced three sets of silicon cookies during her visit to Jlab. She will take equipment to the GWU today.
  - Contract with the GWU is under preparation.
- 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
Module fabrication -- Sasha
- Modules fabricated by Arshak and Sasha (list on Google Drive) (grand total 209)
- Fabricated modules in TEDF
- Status of fabrication
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
Simulations

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