1. First Mock Tile: Resistive ALD and construction
LAPD group meeting : 04/05/2011
Anil Mane, Bob Wagner, Qing Peng, Jeffrey Elam

2. Mock tile parameters: Assumptions: 1) Average R of MCP's = 115 MOhms
2) V across first grid (A) after photocathode = V (acceptable range)
3) E field across gap = 200 V/mm
4) Thicknesses of grids A = 1.1 and D=3.1 mm
5) R George spacer=100* R of MCP1, MCP2
First Grid –A
George xMCPs Second Grid –A
George-2+ 4 *MCPs
Grid-D
RGeorge >>>RMCP
R of Grid spacer D  2* R of Grid spacer A
11/14/2018

3. Coating of carious spacers by ALD:
Coated grid spacers as received grid and George spacers Coated George
George spacer Type A grid spacer Type D grid spacer
Grid spacer coated in batch
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4. Resistance measurement:
Depend on the load
on electrode (contact)
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5. Change in resistance due to geometry:
R=l / A X 
Depend on the load on electrode (contact)
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6. Individual component Rs (M) Stack Rs after each component
Mock tile component Rs
Items
Individual component Rs (M)
Actual Rs when stacked
(M)
Stack Rs after each component
Single MCP
115 NA
Grid spacer D
1.66 13
Bottom 4xMCPs 29 28 41
Top
4xMCPs 27 75
Top grid
spacer A
1.4 15 90
Total Rs =
61.52
90-100
Total Rs After sealing & evacuation =
????
So far we are closed
to target value
11/14/2018

7. Construction of first mock tile:
a) Grid D b) a + George 1 c) b + bottom 4xMCPs d) c + Middle grid A + George 2
Courtesy: Joe & Dean
e) d + top 4xMCPs + Top grid A
g) Anil & Bob Holding mock tile
h) Mock tile after sealing & evacuation
f) full stack in mock tile
11/14/2018

8. Attention needed for mock tile:
Lose contact can cause by insufficient pressure on stack
Short contact due to sealing (side lugs)
Grid space resistance
Current/voltage distribution across the stack (cause only 2 contact top and bottom)
-What potential we need to apply to mock tile?
Heating of the components (Film thickness currently 400A?)
Al photocathode efficiency
Oxidation during firing
Electrode on Grids
Individual contact for each item
Sealing
High efficiency photocathode
Back-up plan (few more mock tile)
Start with 8”x8” sooner (simple integration scheme)
How do we improve:
Nevertheless first mock tile prototype is ready to test 
11/14/2018