photomultiplier


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photomultiplier:

see photoelectric cellphotoelectric cell
or photocell,
device whose electrical characteristics (e.g., current, voltage, or resistance) vary when light is incident upon it. The most common type consists of two electrodes separated by a light-sensitive semiconductor material.
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photomultiplier

(foh-toh-mul -tă-plÿ-er) (photomultiplier tube; phototube) An electronic device used to convert a low-intensity light signal into an electrical signal and to amplify this signal very considerably. It contains a photocathode from which electrons are liberated by the incident light photons. The electrons are accelerated down an evacuated tube by a series of positively charged electrodes to which an increasingly high potential is applied. At each electrode a number of additional electrons are released by each impacting electron (by secondary emission). The electrons are all collected at the final electrode in the chain, which is held at a very high potential, and a large current pulse is produced.

photomultiplier

[¦fōd·ō′məl·tə‚plī·ər]
(electronics)
References in periodicals archive ?
This light is then detected by the photomultipliers.
We also investigated placing an external gamma-ray detector just outside the dewar next to the photomultiplier tube (PMT)s to both monitor external rates and hopefully use the data from this detector to normalize the trapping data to minimize these systematic shifts in the backgrounds.
To make the devices, "students taped short photomultiplier tubes to special plastic scintillator panels and carefully wrapped the whole apparatus in black electrical tape to keep out light," the Times reports.
The 85104 MCP photomultiplier offers high cathode sensitivity, a large cathode area, and photon-counting properties.
Using a solid state charge coupled device (CCD) instead of conventional photomultiplier detectors, the Assure desktop spectrometer provides many of the analytical operations of larger laboratory units with greater flexibility and lower cost.
Plasma emission is studied by a monochromator and a photomultiplier tube hooked up to a computer digitizing card, where Ar I lines are identified in the wavelength range from 300 - 500 nm.
The built-in microprocessor performed the data processing and printed out the final results in relative light units (RLU); one RLU corresponds to the count recorded at the anode of the photomultiplier, divided by 10 and multiplied by the RLU factor, which allows compensation for the inevitable individual fluctuations in the sensitivity of the photomultiplier cathode as determined by the Berthold Company.
In addition, the satellite carries a device called a photomultiplier tube, which allows the camera to take advantage of ultra-low-light conditions.
Our newest Low Light Level Detection Module, the LynX(TM) Silicon Photomultiplier (SiPM) Module for Analytical Instrumentation
They look at how new designs allow for the construction of more compact images with better performance that are not sensitive to magnetic fields as are designs utilizing conventional photomultiplier tubes, allowing for the construction of SPECT and PET systems combined with magnetic resonance scanners in multimodality systems.
No pre-processing or vacuum is required for samples, and the 16-bit photomultiplier and CCD in the system allow for SEM-quality images with true color.