ALD 20µm Microchannel Plates Latest batch, #161-166, 167, 168 20 µm pores (8° bias). New substrate batch. All from INCOM 11863, job # 518627. All show comparable visual features – so same material batch. Visible light transmission for a 20 µm pore #168 ALD MCP . Surface photo for a 20 µm pore #168 ALD MCP with NiCr electrode .

Imaging Performance of ALD MCPs, 33mm Early 2010 July 2011 20µm borosilicate MCP substrates, 60:1 L/d, 8 degree pore bias. ~1000v applied to each MCP. Single MCP tests in DC amplification mode show imaging and gain very similar to conventional MCPs. MCP pairs operated in photon counting mode also show imaging and gain very similar to conventional MCPs. Sample performance has improved dramatically over the last 12 months due to process improvements. 1 MCP, Phosphor readout UV 184nm illumination 2 MCPs, Photon counting

33mm ALD-MCP #164 Background Rate MCP gapped pair (164-163), 20µm pores, 8° bias, 60:1 L/d, achieves <0.08 events cm-2 sec-1. Pulse amplitude distributions for UV 145nm, and for background events, There may be excess background due to detection of ion pump events. 1000 sec background, 496 counts, at 2.5 x 106 gain, 2600v total, with 400v on anode. Background rate is 0.095 events cm-2 sec-1. Improved to 0.08 events cm-2 sec-1 with vacuum.

33mm ALD-MCP #164 Imaging MCP gapped pair (164-163), 20µm pores, 8° bias, 60:1 L/d, Image of 185nm UV light, shows top MCP hex modulation (sharp) and faint MCP hex modulation from bottom MCP. Several triple corner crush defects, but generally very good Gain map (average gain), shows top MCP hex modulation (sharp) and couple of spots where the gain is low. Only a little multi to multi differences.

ANL ALD-MCP #163 Background Rate MCP gapped pair (163-164), 20µm pores, 8° bias, 60:1 L/d Pulse amplitude distributions for UV 145nm, and for background events, here may be excess background due to detection of tank ion events. 3000 sec background, 0.120 events cm-2 sec-1. Uniform background rate is 0.120 events cm-2 sec-1. Not pumped very long, has some tank ion input flux.

33mm ALD-MCP #163 Imaging MCP gapped pair (163-164), 20µm pores, 8° bias, 60:1 L/d, Image of 185nm UV light, shows top MCP hex modulation (sharp) and faint MCP hex modulation from bottom MCP. Several triple corner crush defects, but generally very good Gain map (average gain), shows top MCP hex modulation (sharp) and spots where the gain is low. One characteristic set of multi rows with high gain.

ANL ALD-MCP #161 Background Rate MCP gapped pair (161-164), 20µm pores, 8° bias, 60:1 L/d Pulse amplitude distributions for UV 145nm, and for background events, here may be excess background due to detection of tank ion events. 1000 sec background, 0.145 events cm-2 sec-1. Uniform background rate is 0.129 events cm-2 sec-1. Couple of warm spots, not pumped very long, has some tank ion input flux.

Older 33mm ALD-MCP #140 Imaging MCP gapped pair (140-164), 20µm pores, 8° bias, 60:1 L/d, Image of 185nm UV light, shows top MCP hex modulation (big) and small MCP hex size modulation from bottom MCP. Gain map (average gain), shows top MCP hex modulation. Old MCP substrate shows significant gain variations at boundaries and within multis.

MCP Test Observations New substrates/coatings are much better for imaging and background No triple point voids, and little debris to cause hotspots New substrates/coatings give 0.12 to 0.08 events cm-2 sec-1 background Glass pitting has nothing to do with the background behavior Looks good for use in LAPP tubes, but need to get more timing, lifetest data NEXT STEPS Ready to begin next lifetest:- bake, and scrub with a pair of the new MCPs hope to show better overall stability for gain and background. Have computer controlled bake and scrub data logging now up and running Will need more new 20µm 33mm MCPs for tests – resistance matched!! Other Issues 4 ea 8” 40µm MCPs electroded for Anil ALD tests NEED 8” MCPS for our TESTBED imaging detector!! Electroding 2 ea 40µm 33mm MCPs cut from 8” substrate, ALD done by Anil beforehand. To check 8” 40µm MCP quality. New 8” MCP ship containers sent to ANL with INCOM ship test substrates