Photomultiplier Tubes (PMT)
Did You Know?
The history of photomultiplier dates back to 1934 when it was first documented by RCA group based in Harrison, NJ. Harley Iams and Bernard Salzberg were the first to integrate a photoelectric-effect cathode and single secondary emission amplification stage in a single vacuum envelope and the first to characterize its performance as a photomultiplier with electron amplification gain. Photomultiplier tubes are extensively used as photodetectors in situations where high sensitivity is important. In addition to high sensitivity to a wide spectrum of light from UV to near IR they feature a low noise level, high frequency response and large collection area. These advantages have meant that despite all the advances in photodiode technology, photomultipliers are still used in virtually all cases when low levels of light need to be detected.
Related Resources
Frequently Asked Questions
Photomultiplier Tubes (PMTs) are highly sensitive detectors used to measure low levels of light across a wide range of wavelengths. They consist of a photocathode, a series of dynodes, and an anode. When photons strike the photocathode, electrons are emitted and amplified through the dynode stages, resulting in an output signal proportional to the incident light.
Photomultiplier Tubes (PMTs) operate based on the photoelectric effect and electron multiplication. Incident photons strike the photocathode, causing the emission of photoelectrons. These electrons are then accelerated and amplified through a series of dynodes, resulting in a significant gain in the output signal, allowing for the detection of extremely low levels of light.
Photomultiplier Tubes offer several advantages, including high sensitivity, wide dynamic range, fast response times, low noise, and excellent linearity. They are well-suited for applications requiring low-light detection, such as spectroscopy, fluorescence, scintillation counting, particle physics, and astronomical observations.
Photomultiplier Tubes are available in various models designed for specific wavelength ranges. Depending on the photocathode material used, PMTs can cover a wide spectral range, from ultraviolet (UV) to near-infrared (NIR). It's important to select a PMT with a suitable photocathode for the desired wavelength range of your application.
When choosing a Photomultiplier Tube, consider factors such as the desired wavelength range, quantum efficiency, gain, dark count rate, and dynamic range. Additionally, consider the physical and electrical characteristics, such as size, cooling requirements, and voltage supply, to ensure compatibility with your experimental setup or application requirements.