Electronic Conditioners
... and the collector. The base is very thin and contains fewer doping atoms than the emitter and collector. Thus a very small emitter-base current will cause a much larger emitter-collector current to flow. Transistors are built by stacking three different layers of semiconductor material together. Som ...
... and the collector. The base is very thin and contains fewer doping atoms than the emitter and collector. Thus a very small emitter-base current will cause a much larger emitter-collector current to flow. Transistors are built by stacking three different layers of semiconductor material together. Som ...
4BL exp 2 S17
... side and you will see the glowing filament. An anode biased a few hundred volts V positive relative to the cathode pulls electrons from the cathode and accelerates them in one direction. The electrons emerge from an aperture in the anode with a kinetic energy equal to eV or below. Electrons are not ...
... side and you will see the glowing filament. An anode biased a few hundred volts V positive relative to the cathode pulls electrons from the cathode and accelerates them in one direction. The electrons emerge from an aperture in the anode with a kinetic energy equal to eV or below. Electrons are not ...
Semiconductor Devices
... In September 2003 a new type of blue LED was demonstrated by the company Cree, Inc. to give 240 lm/W at 20 mA. This produced a commercially packaged white light giving 65 lumens per watt at 20 mA, becoming the brightest white LED commercially available at the time, and over four times more efficient ...
... In September 2003 a new type of blue LED was demonstrated by the company Cree, Inc. to give 240 lm/W at 20 mA. This produced a commercially packaged white light giving 65 lumens per watt at 20 mA, becoming the brightest white LED commercially available at the time, and over four times more efficient ...
Atomic Emission Spectrometry - San Diego Unified School District
... photon of just the right amount of energy to move it from one quantum shell to another. Second, when atoms are heated or energized with electricity their electrons can gain energy. This promotes them to the higher-energy shell. When an electron is in a higher-energy shell it is said to be in an exci ...
... photon of just the right amount of energy to move it from one quantum shell to another. Second, when atoms are heated or energized with electricity their electrons can gain energy. This promotes them to the higher-energy shell. When an electron is in a higher-energy shell it is said to be in an exci ...
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.