Single electron amplification in a 'single-MCP plus Micromegas plus pads' detector

摘要

We have tested a new gaseous detector structure based on a tandem of two parts, the first one is a single MCP plate(1) (sometimes called the Microchannel plate or Capillary plate), and the second one is a Micromegas with pad readout. The new detector responds very well to a single electron signal, both in Helium- and Argon-based gases, and it can reach a very large gain. We also measure the ion backflow. Our overall aim is to couple the proposed electrode structure to a Bialkali photocathode. The main advantage of this avenue of research is that such a detector would operate easily in a very large magnetic field, and it could achieve excellent position resolution and large pixelization, compared to existing vacuum-based MCP-PMT detectors, and that the glass-based MCP structure is compatible with the Bialkali photocathode. We propose a new concept of angled MCP holes for the gaseous detectors to reduce the ion backflow towards the photocathode material. (C) 2004 Elsevier B.V. All rights reserved.