Status of ALD 33 mm MCP Development at Argonne Jeffrey Elam, Qing Peng, Anil Mane, Joseph Libera Argonne National Laboratory

Atomic Layer Deposition for Micro channel Plates MCP Structure pore resistive coating (ALD) emissive coating (ALD) conductive coating (evaporation)

Flow Chart of ALD Resistive (RES) and Secondary Electron Emissive (SEE) Layers ALD Group Feedback for optimizing, composition, thickness etc Feedback for optimizing RES, SEE on Si or glass Feed back Completed MCP SEE on silicon SEE Material testing group (Slade) RES testing by ALD group (Qing) Gain Testing Group (Matt) Need faster feedback for optimizing coatings Need vacuum testing setup for high voltage resistant testing Need e-beam evaporation system for end spoiling Need faster feedback for optimizing coatings Major bottleneck is feedback from testing

Flow Chart for MCP Fabrication Incom Glass Plates Acetone sonication clean Air dry at 200C >2h Vacuum dry in ALD system (1 Torr flowing UHP N2) Electrode coating Baking at 400C under N2 ALD RES, SEE coatings in situ Ozone clean Test resistance Deliver for testing

Status of ALD Materials Development RES layer: Many candidates being developed and tested uniformity (SEM, ellipsometry), composition (EDAX, XRF), electrical resistance (Hg probe) 3 new materials ready for gain testing waiting for feedback before applying to Incom glass Resistive coating need substantial characterization directly on MCPs. (need vacuum testing setup – parts being ordered) SEE layer: SEE candidates delivered waiting for feedback

Status of Endspoiling Current procedure Opportunities for E-beam NiCr Au film by thermal evaporator (Hau Wang group) >2 hr one side Dewetting and adhesion problems, poor control over incident angle Need e-beam evaporation of NiCr with rotation, 45 incident angle Opportunities for E-beam NiCr Center of Nanoscale Materials at ANL Proposal accepted, but e-beam is down… Orlando Auciello, MSD, (not operational - requires significant time and money) Beihai Ma, ES, (not operational - requires significant time and money) Robert Erck, MSD, (busy, not available) John Pearson, MSD, (busy, not available) Kwok, Wai-Kwong, (busy, not available) Eileen Hahn, Fermilab – contacted, available, arranging to meet

Sample holder for electrode coating Fab will be completed this week.

Resistance testing setup

2 ¾ in flange for electrical feed through 3 3/8 in flange for adding future parts 3 3/8 in flange for thermal couple feed through 6.44” 2 ¾ in flange to connect to rough pump and Turbo. Cross from Kj lesker, ID of tube is: 1.8445” Length of tube: 6.44” 3-3/8" CF 3.22 2.71 2-3/4" 2" 1-1/2" 4-1/2 (2.04) C-0337-275 $335.00

MCP holder for resistive layer coating PEEK + Metal o-ring MCP Metal o-ring - PEEK

Conclusions The Status of ALD developing for MCPs Multiple ALD material system are waiting for testing Optimizing process is limited by testing feedback. Urgent problems need to be solve for speeding up process Resistivity Layer: Electrode coating equipment In-situ vacuum, high voltage testing tool Gain testing feed back SEE layer: SEE coefficient feedback for ALD film