Incoming photons strike a photocathode to emit primary electrons, which are then accelerated into a series of dynodes. Each dynode collision knocks loose secondary electrons, multiplying the signal by factors of up to a hundred million. They are used in medical imaging, particle physics, and astronomy where detecting single photons is necessary.
Heard on the job
The photomultiplier tube in the spectrometer is saturated, so turn down the laser intensity before you burn it out.
Insider tip
Never expose a powered PMT to ambient room light, as the massive electron cascade will permanently destroy the dynodes.
Also heard as
- PMT