A microchannel plate (MCP) is used to detect single particles (electrons, ions and neutrons[1]) and photons (ultraviolet radiation and X-rays).

The microchannels are typically 5-20 micrometers in diameter, parallel to each other and enter the plate at a small angle to the surface (8-13° from normal).

The impact starts a cascade of electrons that propagates through the channel, amplifying the original signal by several orders of magnitude, depending on the electric field strength and the geometry of the microchannel plate.

Some anodes are designed to allow spatially resolved ion collection, producing an image of the particles or photons incident on the plate.

The gain of an MCP is very noisy, meaning that two identical particles detected in succession will often produce wildly different signal magnitudes.

Thusly employed, MCPs are capable of measuring particle arrival times with high resolution, making them ideal detectors for mass spectrometers.

Most modern MCP detectors consist of two microchannel plates with angled channels, rotated 180° from each other - producing a shallow chevron (v-like) shape.

The two MCPs can either be pressed together to preserve spatial resolution, or have a small gap between them to spread the charge across multiple channels, which further increases the gain.

A torus is the optimum compromise between low capacitance and short path and for similar reasons, usually no dielectric (Markor) is placed into this region.

To save space and make the impedance match less critical, the taper is often reduced to a small 45° cone on the backside of the anode plate.

The typical 500 volts between the backside of the last MCP and the anode cannot be fed directly into the preamplifier; the inner or the outer conductor needs a DC block, that is, a capacitor.

A pulse of varying length, but stable height and a low jitter leading edge is sent to the time to digital converter.

With high count rates or slow detectors (MCPs with phosphor screen or discrete photomultipliers), pulses overlap.

Each element has a diameter of 1 mm and consists of an electrostatic lens focusing arriving electrons through a 30 μm hole of a grounded sheet of aluminium.

A 1 GHz real-time display CRT for an analog oscilloscope (the Tektronix 7104) used a microchannel plate placed behind the phosphor screen to intensify the image.