Extended lifetime MCP-PMTs: Characterisation and lifetime measurements of ALD coated microchannel plates, in a sealed photomultiplier tube
Extended lifetime MCP-PMTs: Characterisation and lifetime measurements of ALD coated microchannel plates, in a sealed photomultiplier tube
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DOI：
10.1016/j.nima.2013.07.023
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发表时间：
2013-12-21
影响因子：
1.4
通讯作者：
Howorth, Joh
中科院分区：
文献类型：
--
作者：
Conneely, Thomas M.;Milnes, James S.;Howorth, Joh
微通道板（MCP）的原子层沉积（ALD）涂层已被证明在MCP-PMT（MCP光电倍增管）中提供显着的性能优势。ALD是用于在衬底上存款原子单层的化学气相工艺。已经开发了一种工艺以将具有改进的二次发射产率（SEY）的表面存款到MCP衬底上。更高SEY的主要优点是能够在单个MCP上以相同的工作电压实现显著更高的增益。除此之外，怀疑通过ALD涂覆沉积的原子单层防止MCP玻璃中的气态污染物的解吸。在解吸过程中产生的离子被广泛认为是导致MCP-PMT中光阴极老化的直接原因，从而导致ALD涂层可以提高MCP-PMT寿命的希望。为了充分验证ALD涂覆的MCP的性能，制造了两个MCP-PMT，一个ALD涂覆的，另一个未涂覆的用作参考。测量了每个探测器的增益、DQE、脉冲形状和定时抖动，然后对管进行了寿命测试。发现ALD涂覆的管在相同的操作电压下具有更高的增益，同时在其他性能特性上等同于标准MCP。ALD涂层给出了显著改善的寿命，在5.16 C cm（-2）总电荷提取后，对光阴极QE没有可测量的影响，尽管MCP增益下降了约35%。(C)2013爱思唯尔有限公司版权所有。
Atomic layer deposition (ALD) coating of microchannel plates (MCP) has been shown to offer significant performance advantages in MCP-PMTs (MCP Photomultiplier Tube). ALD is a chemical vapour process used to deposit atomic mono-layers on a substrate. A process has been developed to deposit a surface with improved secondary emission yield (SEY) on to an 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 prevent desorption of gaseous contaminants in the MCP glass. The ions produced during desorption are widely believed to be a direct cause of photocathode ageing in MCP-PMTs, leading to the hope that ALD coating can improve the MCP-PMT lifetime. To fully characterise the performance of ALD coated MCPs, two MCP-PMTs were manufactured, one ALD coated and the other uncoated to be used as a reference. 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 cm(-2) total charge extracted, there was no measurable effect on the photocathode QE, although the MCP gain dropped by approximately 35%. (C) 2013 Elsevier B.V. All rights reserved.