Microchannel Plate (MCP)

From Night Vision Wiki
Diagram of a microchannel plate
Diagram of a microchannel plate

The microchannel plate (MCP) is a core technology used in image intensifiers. An MCP is a secondary electron multiplier consisting of an array of millions of very thin glass channels (glass pipes) bundled in parallel and sliced in the form of a disk. Each channel works as an independent electron multiplier. Electrons entering an MCP are repeatedly multiplied by secondary emission within each channel and are released from the output end of the MCP. An MCP can accelerate and multiply a spatial stream of electrons passing through it, resulting in a stronger signal on the emitting end. The dynamic range (linearity) of an image intensifier depends on the so-called strip current which flows through the MCP during operation. When a higher dynamic range is required, a low-resistance MCP is preferable.

A MCP features small holes cut in an angle (usually between 30° and 40°). Common hole sizes are 12, 10 and 6 microns. 4 micron holes were tested on separate occasions by L3 and Photonis, but weren't developed into a production line due to the low yield during the production compared to the gains in performance.