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MCP from Glass Substrates. Jeffrey Elam Argonne National Laboratory April 14, 2009. MCP Structure. pore. resistive coating (ALD) emissive coating (ALD) conductive coating (thermal evaporation). What ALD Film for Resistive Coating?. ZnO: conductor Al 2 O 3 : insulator
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MCP from Glass Substrates Jeffrey Elam Argonne National Laboratory April 14, 2009
MCP Structure pore • resistive coating (ALD) • emissive coating (ALD) • conductive coating (thermal evaporation)
What ALD Film for Resistive Coating? • ZnO: conductor • Al2O3: insulator • ZnO/ Al2O3 alloy – tunable resistivity
What Composition ALD Film for Resistive Coating? number of pores in MCP : # pores = Aplate/Apore*(open area ratio) = 4.4x105 pores Aplate = area of MCP, Apore = area of one pore resistance of one pore: Rpore = Rtot * # pores = 4.4x1013Ω Rtot = resistance of MCP (Target: 100 MΩ) cross sectional area of film: Afilm =πr2- π(r-t)2 ~ πtd = 0.012t cm r = pore radius, t = film thickness resistivity of film: ρ = Rpore Afilm/L = (3.3x1012) t Ω cm ρ = resistivity of film (Ω cm), L=pore length (0.16 cm) Convenient thickness: t=100 nm = 10-5 cm, ρ = 3.2x107Ω cm ~70% Zn
Emissive Coating • Arradiance identified MgO and Al2O3 (Zeke Isepov) • Al2O3 is easiest for first try • What thickness?
Conducting Coating • Thermal evaporation (building 200, Schlueter) • Material? Thickness?