“photomultiplier”的概念、定义、翻译、参考文献-科学参考

photomultiplier

Physics

A sensitive type of photoelectric cell in which electrons emitted from a photocathode are accelerated to a second electrode where several electrons are liberated by each original photoelectron, as a result of secondary emission. The whole process is repeated as many times as necessary to produce a useful electric current by secondary emission from the last electrode. A photomultiplier is thus a photocathode with the output amplified by an electron multiplier. The initial photocurrent can be amplified by a factor of 10⁸. Photomultipliers are thus useful when it is necessary to detect low intensities of light, as in stellar photometry, star and planet tracking in guidance systems, and more mundanely in process control.

Astronomy

An evacuated electronic tube which converts light into a measurable electric current. Light falling on a photocathode releases electrons, which are accelerated by an electric field and attracted to the first dynode (positive electrode), where they liberate more electrons which are attracted to the second dynode, and so on. A common type of photomultiplier in astronomical use has ten dynodes, each at an increasingly positive electric potential. The flow of electrons arriving at the final anode is proportional to the amount of light falling on the photocathode. Photomultipliers are widely used for photometric measurements in astronomy, such as of variable stars.

Electronics and Electrical Engineering

An electron multiplier that contains a photocathode. Primary electrons, emitted from the photocathode as a result of the photoelectric effect, initiate the cascade. A suitable scintillation crystal is often used as the source of illumination for the photocathode in order to provide a sensitive radiation detector or counter.

单词	photomultiplier
释义	photomultiplier Physics A sensitive type of photoelectric cell in which electrons emitted from a photocathode are accelerated to a second electrode where several electrons are liberated by each original photoelectron, as a result of secondary emission. The whole process is repeated as many times as necessary to produce a useful electric current by secondary emission from the last electrode. A photomultiplier is thus a photocathode with the output amplified by an electron multiplier. The initial photocurrent can be amplified by a factor of 10⁸. Photomultipliers are thus useful when it is necessary to detect low intensities of light, as in stellar photometry, star and planet tracking in guidance systems, and more mundanely in process control. Astronomy An evacuated electronic tube which converts light into a measurable electric current. Light falling on a photocathode releases electrons, which are accelerated by an electric field and attracted to the first dynode (positive electrode), where they liberate more electrons which are attracted to the second dynode, and so on. A common type of photomultiplier in astronomical use has ten dynodes, each at an increasingly positive electric potential. The flow of electrons arriving at the final anode is proportional to the amount of light falling on the photocathode. Photomultipliers are widely used for photometric measurements in astronomy, such as of variable stars. Electronics and Electrical Engineering An electron multiplier that contains a photocathode. Primary electrons, emitted from the photocathode as a result of the photoelectric effect, initiate the cascade. A suitable scintillation crystal is often used as the source of illumination for the photocathode in order to provide a sensitive radiation detector or counter.
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