11-15 February 2013
Vienna University of Technology
Europe/Vienna timezone

Extended lifetime MCP-PMTs: Characterisation and Lifetime measurements of ALD coated Microchannel Plates, in a sealed photomultiplier tube

Not scheduled
50m
Vienna University of Technology

Vienna University of Technology

Gußhausstraße 25-29, 1040 Wien (Vienna), Austria
Board: 74
Poster Electronics

Speaker

Mr Thomas Conneely (Photek LTD)

Description

Atomic Layer Deposition (ALD) coating of Microchannel Plates (MCP) has been shown to offer significant performance advantages MCP-PMTs. ALD is a chemical process used to deposit atomic mono-layers on a substrate. A process has been developed to deposit a surface with improved secondary emission yield on to a MCP substrate. The principal advantage of a higher SEY is the ability to achieve significantly higher gain at the same operating voltage across a single MCP. Further to this, it is suspected the atomic mono-layers deposited by ALD coating prevents desorption of gaseous contaminants in the MCP glass. The ions produced during desorption are widely believed to be a direct cause of photocathode aging in MCP-PMTs, leading to the hope that ALD coating can improve MCP-PMT lifetime. To fully characterise the performance of ALD coated MCPs two MCP-PMTs were manufactured, one ALD coated and the other used as a control. Each detector’s gain, DQE, pulse shape and timing jitter were measured followed by a life test of the tubes. The ALD coated tube was found to have a higher gain at the same operating voltage, whilst being equivalent to a standard MCP in other performance characteristics. ALD coating gave a dramatically improved life time, after 5.16 C/cm2 total charge extracted, there was no measurable effect on photocathode QE, although MCP gain dropped by approximately 35%.
quote your primary experiment MCP detector development

Primary authors

Dr James Milnes (Photek LTD) Mr Thomas Conneely (Photek LTD)

Presentation Materials