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In condensed matter physics, scintillation (/ ˈ s ɪ n t ɪ l eɪ ʃ ən / SIN-til-ay-shun) is the physical process where a material, called a scintillator, emits ultraviolet or visible light under excitation from high energy photons (X-rays or gamma rays) or energetic particles (such as electrons, alpha particles, neutrons, or ions).
CsI(Tl) is only slightly hygroscopic and does not usually require an airtight enclosure. GaAs or gallium arsenide (suitably doped with silicon and boron impurities) is a cryogenic n-type semiconductor scintillator with a low cryogenic bandgap (1.52 eV) and high light output (100 photons/keV) in the infra-red (930 nm). The absence of thermally ...
The scintillator consists of a transparent crystal, usually a phosphor, plastic (usually containing anthracene) or organic liquid (see liquid scintillation counting) that fluoresces when struck by ionizing radiation. Cesium iodide (CsI) in crystalline form is used as the scintillator for the detection of protons and alpha particles.
The relation is: = +. where L is the light yield, S is the scintillation efficiency, dE/dx is the specific energy loss of the particle per path length, k is the probability of quenching, [1] and B is a constant of proportionality linking the local density of ionized molecules at a point along the particle's path to the specific energy loss; [1] "Since k and B appear only as a product, they act ...
Liquid scintillation counter. Samples are dissolved or suspended in a "cocktail" containing a solvent (historically aromatic organics such as xylene or toluene, but more recently less hazardous solvents are used), typically some form of a surfactant, and "fluors" or scintillators which produce the light measured by the detector.
A time-of-flight (TOF) detector is a particle detector which can discriminate between a lighter and a heavier elementary particle of same momentum using their time of flight between two scintillators [1].
Indirect detectors contain a layer of scintillator material, typically either gadolinium oxysulfide or cesium iodide, which converts the x-rays into light.Directly behind the scintillator layer is an amorphous silicon detector array manufactured using a process very similar to that used to make LCD televisions and computer monitors.
The detector consists primarily of a scintillator inside a Faraday cage inside the specimen chamber of the microscope. A low positive voltage is applied to the Faraday cage to attract the relatively low energy (less than 50 eV by definition) secondary electrons. Other electrons within the specimen chamber are not attracted by this low voltage ...