Nuclear_Chapter 6
... atoms are excited and emit photons, which are directed at the photomultiplier tube's photocathode which is connected to the negative of a high voltage source. Each incident photon releases an electron. A number of accelerating electrodes called dynodes are arranged in the tube at increasing positive ...
... atoms are excited and emit photons, which are directed at the photomultiplier tube's photocathode which is connected to the negative of a high voltage source. Each incident photon releases an electron. A number of accelerating electrodes called dynodes are arranged in the tube at increasing positive ...
34.1 Flow of Charge
... • Flow of electric charge through wire = amperes • Solids – electrons carry charge because they are free to move • Protons are fixed inside nucleus • Measured in amperes – SI unit = I • One coulomb of charge per second • One coulomb = 6.24 billion electrons • Current carrying wire normally has a cha ...
... • Flow of electric charge through wire = amperes • Solids – electrons carry charge because they are free to move • Protons are fixed inside nucleus • Measured in amperes – SI unit = I • One coulomb of charge per second • One coulomb = 6.24 billion electrons • Current carrying wire normally has a cha ...
File - The Physics Doctor
... Gold-Leaf Experiment 1) In this experiment, the metal cap (and as such, the stem and gold leaf) were given a negative charge 2) This caused the gold leaf to ______ because _________________ 3) Different colours of light were then shone onto the metal cap 4) Red light had no effect, but ultraviolet ...
... Gold-Leaf Experiment 1) In this experiment, the metal cap (and as such, the stem and gold leaf) were given a negative charge 2) This caused the gold leaf to ______ because _________________ 3) Different colours of light were then shone onto the metal cap 4) Red light had no effect, but ultraviolet ...
Photomultiplier
Photomultiplier tubes (photomultipliers or PMTs for short), members of the class of vacuum tubes, and more specifically vacuum phototubes, are extremely sensitive detectors of light in the ultraviolet, visible, and near-infrared ranges of the electromagnetic spectrum. These detectors multiply the current produced by incident light by as much as 100 million times (i.e., 160 dB), in multiple dynode stages, enabling (for example) individual photons to be detected when the incident flux of light is very low. Unlike most vacuum tubes, they are not obsolete.The combination of high gain, low noise, high frequency response or, equivalently, ultra-fast response, and large area of collection has maintained photomultipliers an essential place in nuclear and particle physics, astronomy, medical diagnostics including blood tests, medical imaging, motion picture film scanning (telecine), radar jamming, and high-end image scanners known as drum scanners. Elements of photomultiplier technology, when integrated differently, are the basis of night vision devices.Semiconductor devices, particularly avalanche photodiodes, are alternatives to photomultipliers; however, photomultipliers are uniquely well-suited for applications requiring low-noise, high-sensitivity detection of light that is imperfectly collimated.