Difference between revisions of "September 9, 2019 FCAL Insert Design Meeting"

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(Created page with "== Meeting Time and Place == Thursday August 15 3pm At Jefferson Lab, room TED 2504 * Present - Sasha Somov, Josh Crafts, Vlad, Eugene, Stephanie, Keith Harding, Tim == Age...")
 
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== Agenda ==
 
== Agenda ==
−
* Discuss 40x40 crystal assembly
+
* Discuss 40x40 crystal assembly with 19 Lead glass modules around
−
** 40x40 crystal matrix layout  [[Media:40x40_crystal_matrix_layout.pdf]]
+
** Crystals move to 12.5 cm from US face of lead glass
 +
** 40x40 crystal matrix starts with shim to be able to go to 32x32 fairly easy.
 
** Decision to pre-measure stacks of crystals and the existing FCAL to determine bottom row offsets
 
** 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
 
* Discuss installing Rohacel US of crystals to fill hole and support the lead glass blocks
 
** Rohacel properties  [[Media:Rohacel cut sheet.pdf]]
 
** Rohacel properties  [[Media:Rohacel cut sheet.pdf]]
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** http://www.phenix.bnl.gov/WWW/publish/bosze/phenixnote272/radiation.html  (same data)
 
** http://www.phenix.bnl.gov/WWW/publish/bosze/phenixnote272/radiation.html  (same data)
 
* Discuss Tungsten absorber
 
* Discuss Tungsten absorber
−
** How many crystals does it cover?
+
** Cover 1.5 crystals ok?
−
** How to support it and the blocks above
+
** Rohacell supported
 
* Monitoring System
 
* Monitoring System
−
** Is acrylic sheet good enough for crystals?
+
** Use Acrylic sheet, how thick?
−
* How were original FCAL lead glass modules stacked?
+
** How to attach fibers?
−
** Matt Shepherd stated that they were rotated 90 degrees every other one and bottom row was shimmed as required.
+
* Cooling of blocks - 2.1 KW needed
−
** What should the shim material be
+
** 2 Chillers like those used for BCAL ($16K ea)
−
* 3D Screenshots
+
** 4 water to air Heat exchangers around crystal area
−
** Overall Iso View Sept 2018 [[Media:Iso.png]]
+
** potted copper tube into aluminum blocks
−
** Cooling Iso View Sept 2018 [[Media:Cooling Iso.jpg]]
+
** Cooling of inner tube - removeable plate
−
** Cooling-compression Plate Iso View Sept 2018 [[Media:Cooling-compression Iso.jpg]]
+
* electronics patch panels DS of crystal pmts
 +
* Brass strap soldering progress
  
 
== Minutes ==
 
== Minutes ==
−
* 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]] . Adding additional layers around the this would mean we would have to buils a new support structure to accommodate. The 40x40 crystal stack requires the 1st lead glass stack to be shimmed 3-4mm to ensure we can easily convert to 32x32 if we do not have enough crystals or pmts.
 
−
* Discussed the cabling and patch panel requirements for the crystal modules. A type similar to the ComCal was discussed but with smaller SHV connectors. It was decided to take a field trip into the FCAL darkroom to discuss.
 
−
* Tungesten absorber can be supported by the rohacell and be 6 cm thick. Sasha will need to look at the total coverage or the absorber.
 
−
* the IG110 Rohacell appears to be radiation hard (enough) and stiff enough. The density of 110 Kg/cubic meter should have a low impact on the physics.
 
−
* The crystals should be moved back 2.5 cm (to 12.5 cm from US face)to be centered on the lead glass
 
−
* We discussed the crystal modules and the mag shielding. We need to make the steel shield 6mm longer (if 2mm cookie used) to fit properly. We want to look at using silicone cookies instead of optical grease. Josh also would like to test this joint as well as the soldering of the brass straps to eliminate heat stress and failures.
 
−
* We decided we should use aluminum shims for the stacking of the blocks.
 
−
* Discussed cooling system using copper tubing brazed to the aluminum blocks vs. holes through the aluminum blocks with pipe thread connections. We will have to look at the heat transfer characteristics and the pros and cons of each including fabrication, installation and repairs. It was pointed out that the BCAL has 192 pipe thread fittings that have not leaked to date.
 
−
* It was decided that the acryllic sheet monitoring system should be sufficient for the crystals.
 
  
 
== Action items ==
 
== Action items ==
−
* Continue with 40x40 crystal design and 19 lead glass blocks surrounding them. Move the crystals down stream 2.5cm. (Keith)
 
−
* Develop cooling design using those similar to BCAL. Keith to get with Josh Foyles to discuss pros and cons of each.
 
−
* Develop monitoring system layout (Keith/Tim)
 
−
* Go into the FCAL dark room to see layout and discuss cabling design for crystals (All)
 
−
* Perform heat load calculations to define best cooling system (Tim)
 
−
* Layout cabling system concept in 3D (Keith)
 
−
* Cut down long steel shield for Josh to perform strap/cookie tests (Tim)
 
−
* Get cookie samples for Josh to use (Tim)
 
−
* Determine tungsten absorber coverage (Sasha)
 
−
* Work on brass strap soldering techniques and cookie transmission tests (Josh)
 
−
* Invite Fernando to next meeting (Tim)
 

Revision as of 11:07, 9 September 2019

Meeting Time and Place

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

  • Present - Sasha Somov, Josh Crafts, Vlad, Eugene, Stephanie, Keith Harding, Tim

Agenda

  • Discuss 40x40 crystal assembly with 19 Lead glass modules around
    • Crystals move to 12.5 cm from US face of lead glass
    • 40x40 crystal matrix starts with shim to be able to go to 32x32 fairly easy.
    • Decision to pre-measure stacks of crystals and the existing FCAL to determine bottom row offsets
  • Discuss installing Rohacel US of crystals to fill hole and support the lead glass blocks
  • Discuss Tungsten absorber
    • Cover 1.5 crystals ok?
    • Rohacell supported
  • Monitoring System
    • Use Acrylic sheet, how thick?
    • How to attach fibers?
  • Cooling of blocks - 2.1 KW needed
    • 2 Chillers like those used for BCAL ($16K ea)
    • 4 water to air Heat exchangers around crystal area
    • potted copper tube into aluminum blocks
    • Cooling of inner tube - removeable plate
  • electronics patch panels DS of crystal pmts
  • Brass strap soldering progress

Minutes

Action items

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