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

Mock tile parameters: Assumptions: 1) Average R of MCP's = 115 MOhms 2) V across first grid (A) after photocathode = 300-700 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 -1 + 4xMCPs 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

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 11/14/2018

Resistance measurement: Depend on the load on electrode (contact) 11/14/2018

Change in resistance due to geometry:  R=l / A X  Depend on the load on electrode (contact) 11/14/2018

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

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

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