1. Space Sciences Laboratory, University of California, Berkeley SSL-UCB, ALD MCP Test Progress ML201-B-2 12nm ALD After cleaning ML201-B-1 6nm ALD

2. Space Sciences Laboratory, University of California, Berkeley Initial Imaging Results on Standard MCPs with 6nm ALD coating, single MCP, phosphor 1150v MCP, 2800v Screen, UV flood Photonis ML201-B-1 MCP, 86MΩ 1050v MCP, 2900v Screen, UV flood Photonis ML201-B-1 MCP, 86MΩ Shows definite enhancement of brightness in ALD area, due to GAIN increase! No degradation of image quality, except at the boundary zone for coating ALD No ALD

3. Space Sciences Laboratory, University of California, Berkeley 1100v MCP, 2700v Screen, UV flood Photonis ML201-B-2 MCP, 90MΩ Shows definite suppression of brightness in ALD area, UV QE reduction! No degradation of image quality, except at the boundary zone for coating ALD No ALD Initial Photon Counting Results with 12nm ALD coating, single MCP, phosphor

4. Space Sciences Laboratory, University of California, Berkeley Initial Photon Counting on Standard MCPs Stacked as a pair with 6nm/12nm ALD coating 2400v MCPs, UV flood, MCP pair, Photonis ML201-B-1 (6nm) top, ML201-B-2 bottom (12nm) 2400v MCPs, UV flood, MCP pair, Photonis ML201-B-1 (6nm) top, ML201-B-2 bottom (12nm) GAIN MAP IMAGE 6 nm/12 nm 6 nm/0 nm 0 nm/0 nm 0 nm/12 nm 6 nm/12 nm 6 nm/0 nm 0 nm/0 nm 0 nm/12 nm Using our photon counting imaging detector (25mm cross delay line) we stacked the ALD coated MCPs in a pair, 6nm on top, 12nm underneath, with the ALD layers rotated to give four combinations of MCP configurations. Legend:- ?? nm/ ?? nm Top MCP / bottom MCP

5. Space Sciences Laboratory, University of California, Berkeley Initial Photon Counting Results on Standard MCPs Normal uncoated MCP area, BUT - low UV response due to small events being electronically rejected! 6 nm/12 nm 6 nm/0 nm 0 nm/0 nm 0 nm/12 nm 12 nm coated MCP area under uncoated MCP, higher UV response due to higher gain - no rejected events. 6nm coated MCP over uncoated MCP, - low UV response due to ALD coating suppressing nichrome photoemission! 6nm coated MCP over 12nm coated MCP, - low UV response due to ALD coating suppressing the nichrome photoemission! IMAGING

6. Space Sciences Laboratory, University of California, Berkeley Initial Photon Counting Results on Standard MCPs 6 nm/12 nm 6 nm/0 nm 0 nm/0 nm 0 nm/12 nm 12 nm MCP under uncoated MCP is 3.5x higher UV QE than 6nm coated on top of 12nm MCP uncoated MCPs are 1.5x higher UV QE than 6nm coated MCP on top of uncoated MCP Image MAP Histograms

7. Space Sciences Laboratory, University of California, Berkeley 6 nm/12 nm 6 nm/0 nm 0 nm/0 nm 0 nm/12 nm Initial Photon Counting Results on Standard MCPs Normal uncoated MCP area, Lowest gain! 12 nm coated MCP area under uncoated MCP, - moderate gain increase. 6nm coated MCP over uncoated MCP, - moderate gain increase! 6nm coated MCP over 12nm coated MCP, - big gain increase! GAIN MAP Average gain is about 5 x 10 6

8. Space Sciences Laboratory, University of California, Berkeley Initial Photon Counting Results on Standard MCPs 6 nm/12 nm 0 nm/0 nm 0 nm/12 nm 6 nm/0 nm GAIN MAP Histograms 6nm on top or 12 nm under Gives similar gain enhancement 6nm on top gives x2 gain enhancement 6nm on top of 12nm gives x2 gain enhancement 6nm on top plus 12 nm under gives >4x gain enhancement

9. Space Sciences Laboratory, University of California, Berkeley Initial Photon Counting Results on Standard MCPs Stacked as a pair with 6nm/12nm ALD coating Summary ALD Al 2 O 3 coatings decrease the UV efficiency significantly Need to put ALD under the electrode if we want UV QE ALD Al 2 O 3 coatings increase the MCP gain significantly Both top and bottom MCP coatings are beneficial ALD Al 2 O 3 coatings don’t seem to affect the imaging quality Still to do Consequences for background rates? Wider range of applied voltages/gains More detailed imaging performance issues Scrubbing and thermal ramifications