ALD 20m Microchannel Plates Latest batch 161 166

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 Surface photo for a 20 µm pore #168 ALD MCP with Ni. Cr electrode.

Imaging Performance of ALD MCPs, 33 mm Early 2010 1 MCP, Phosphor readout 20µm borosilicate MCP substrates, 60: 1 L/d, 8 degree pore bias. ~1000 v applied to each MCP. Single MCP tests in DC amplification mode show imaging and gain very similar to conventional MCPs. UV 184 nm illumination 2 MCPs, Photon counting July 2011 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.

33 mm 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. 106 1000 sec background, 496 counts, at 2. 5 x gain, 2600 v total, with 400 v on anode. Background rate is 0. 095 events cm-2 sec-1. Improved to 0. 08 events cm-2 sec-1 with vacuum. Pulse amplitude distributions for UV 145 nm, and for background events, There may be excess background due to detection of ion pump events.

33 mm ALD-MCP #164 Imaging MCP gapped pair (164 -163), 20µm pores, 8° bias, 60: 1 L/d, Image of 185 nm 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 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. Pulse amplitude distributions for UV 145 nm, and for background events, here may be excess background due to detection of tank ion events.

33 mm ALD-MCP #163 Imaging MCP gapped pair (163 -164), 20µm pores, 8° bias, 60: 1 L/d, Image of 185 nm 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 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. Pulse amplitude distributions for UV 145 nm, and for background events, here may be excess background due to detection of tank ion events.

Older 33 mm ALD-MCP #140 Imaging MCP gapped pair (140 -164), 20µm pores, 8° bias, 60: 1 L/d, Image of 185 nm 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 33 mm 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 33 mm 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