Imaging Laboratory Exercise Scanning Electron Microscope
... of the illuminating light. As a result of this limitation, the optical microscope's resolution is roughly 0.1 m - too large to let us see even viruses, let alone atoms. To read more about this limitation, visit the pages on Limiting Vision. This limit is roughly the size of the wavelength of the pro ...
... of the illuminating light. As a result of this limitation, the optical microscope's resolution is roughly 0.1 m - too large to let us see even viruses, let alone atoms. To read more about this limitation, visit the pages on Limiting Vision. This limit is roughly the size of the wavelength of the pro ...
Semiconductors_TG.ver3
... for electron conduction. These ideas are then used to describe the operation of a p-n junction (diode) in forward and reverse bias. The quantum-mechanical nature of semiconductors is also explored. ...
... for electron conduction. These ideas are then used to describe the operation of a p-n junction (diode) in forward and reverse bias. The quantum-mechanical nature of semiconductors is also explored. ...
lecture 4 sem probe top down
... literature and various EM reference books (see for example. Reimer - Scanning Electron Microscopy Springer- Verlag 1985) The first thing to make clear is that the accelerating voltage of the microscope (HV) does not have a great deal to do with electron emission per se. There is an interaction of th ...
... literature and various EM reference books (see for example. Reimer - Scanning Electron Microscopy Springer- Verlag 1985) The first thing to make clear is that the accelerating voltage of the microscope (HV) does not have a great deal to do with electron emission per se. There is an interaction of th ...
Molecular Luminescence Spectroscopy
... from molecules that have been excited to higher energy levels by absorption of electromagnetic radiation. ...
... from molecules that have been excited to higher energy levels by absorption of electromagnetic radiation. ...
Conversion of heat and light simultaneously using a vacuum
... ejection of electrons [1]. This ‘‘Photoelectric Effect’’ produces a voltage and current when light of the proper wavelength shines on a cleaned surface [2]. For most metals, the wavelengths of light that stimulate this effect are in the ultraviolet region, and the photocurrents are feeble. Later, it ...
... ejection of electrons [1]. This ‘‘Photoelectric Effect’’ produces a voltage and current when light of the proper wavelength shines on a cleaned surface [2]. For most metals, the wavelengths of light that stimulate this effect are in the ultraviolet region, and the photocurrents are feeble. Later, it ...
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.