August 15, 2019 FCAL Insert Design Meeting

Meeting Time and Place

Thursday August 15 3pm At Jefferson Lab, room TED 2504

Discuss 40x40 crystal assembly
- 40x40 crystal matrix layout Media:40x40_crystal_matrix_layout.pdf
- Decision to pre-measure stacks of crystals and the existing FCAL to determine bottom row offsets
- Shimming of row above crystals may be needed
Discuss installing Rohacel US of crystals to fill hole and support the lead glass blocks
- Rohacel properties Media:Rohacel cut sheet.pdf
- Radiation Hardness https://p25ext.lanl.gov/phenix/mvd/notes/1997/PHENIX-MVD-97-5/radiation.html
- http://www.phenix.bnl.gov/WWW/publish/bosze/phenixnote272/radiation.html (same data)
Discuss Tungsten absorber
- How many crystals does it cover?
- How to support it and the blocks above
Monitoring System
- Is acrylic sheet good enough for crystals?
How were original FCAL lead glass modules stacked?
- Matt Shepherd stated that they were rotated 90 degrees every other one and bottom row was shimmed as required.
- What should the shim material be
3D Screenshots
- Overall Iso View Sept 2018 Media:Iso.png
- Cooling Iso View Sept 2018 Media:Cooling Iso.jpg
- Cooling-compression Plate Iso View Sept 2018 Media:Cooling-compression Iso.jpg

Discussed overall geometry and decided 40x40 crystal plus 19 lead glass block layers surrounding the crystals covered a wide enough area. The attached layout shows the trajectory of the particles grazing the BCAL Media:Particle trajectory through BCAL.pdf

We will go with the 40x40 matrix for the design, we will have to shim if the install changes to 32x32
Need to define rohacell
Need to define monitoring system
Need to define tungsten absorber geometry
Need to perform heat load calcs
Need to define cable management system
Need to define shim material