How does a photomultiplier tube detector work?
A photomultiplier tube, useful for light detection of very weak signals, is a photoemissive device in which the absorption of a photon results in the emission of an electron. These detectors work by amplifying the electrons generated by a photocathode exposed to a photon flux.
Which detector is used in photomultiplier?
Photomultipliers are used in research laboratories to measure the intensity and spectrum of light-emitting materials such as compound semiconductors and quantum dots. Photomultipliers are used as the detector in many spectrophotometers.
How do you test a photomultiplier tube?
The PMTs are to be tested by flashing a very dim LED light in the dark box with them. The LED is activated using the lowest possible voltage to emit the smallest number of photons possible. The light flashes very quickly (at roughly 10 Hz) and remains lit for only 11ns at a time.
How is PMT used?
Photomultiplier tubes (often abbreviated as PMT) make use of this external photoelectric effect and are superior in response speed and sensitivity (low-light-level detection). They are widely used in medical equipment, analytical instruments and industrial measurement systems.
How does a photomultiplier tube detect visible electromagnetic radiation?
Photomultiplier tubes (PMT’s) utilize the photoelectric effect and the secondary emission of electrons to provide high current gains upon initial detection of a photon. Briefly, incident photons are directed towards a photocathode made up of a low work-function metal or semiconductor material.
Why is photomultiplier tube used?
photomultiplier tube, electron multiplier tube that utilizes the multiplication of electrons by secondary emission to measure low light intensities. It is useful in television camera tubes, in astronomy to measure intensity of faint stars, and in nuclear studies to detect and measure minute flashes of light.
What is in a photomultiplier tube?
A photomultiplier tube (PMT) consists of a photocathode followed by an electron multiplier. A single photon ejects an electron from the photocathode. Electric fields in the PMT accelerate the electron into another surface called a dinode.