MCP — Microchannel Plate

A microchannel plate takes the electron-multiplier idea and makes it massively parallel. The plate is riddled with millions of tiny channels, and each channel is a miniature electron multiplier. Ions arriving at different positions enter different channels, so many are detected at once — and because the channels are short, the response is extremely fast, which suits TOF's nanosecond timing.

How it works

Ions strike many channels across the face at the same time. Plates are usually stacked in a "chevron" (two plates at opposing angles) to boost the gain.

The parallelism also means an MCP can preserve where an ion hit, so it works as a position-sensitive detector too. That combination of speed and spatial information is why MCPs are the standard detector on TOF instruments.