MCP detector

Microchannel plate detectors (MCP) detect electrons, ions, or high-energy photons. They can be viewed as a further development of simple channeltrons (CEMs) and consist of a plate-shaped array of glass capillaries (between 10μm and 100μm inside diameter), which are provided with a semiconductor material on the inside. This layer on the capillary walls has electron-emitting properties, whereby the lead glass ensures a high electrical resistance between the capillaries. Each of the capillaries acts as an electron multiplier during detection: an accelerating voltage is applied between the two metalized plate sides and the capillary is arranged slightly tilted relative to the plate axis, so that incident electrons are certain to hit the wall of the respective capillary several times and generate secondary electrons again and again. These can then be recorded as measurable pulses with the help of fast TDCs or ADCs. Microchannel plates work with particularly low noise and, thanks to the matrix arrangement, also provide spatial information if required. This is beneficial for low-light imaging applications such as FLIM. Such multichannel plates are therefore also referred to as pixelated MCPs. MCP configurations with double or Z-stack MCP detectors are available for better resolution.

The following video shows an MCP detector receiving particles in a MALDI-TOF measurement: