Scintillator

A scintillator is a material that exhibits scintillation — the property of luminescence when excited by ionizing radiation. Luminescent materials, when struck by an incoming particle, absorb its energy and scintillate, i.e., re-emit the absorbed energy in the form of light. Sometimes, the excited state is metastable, so the relaxation back out of the excited state is delayed (necessitating anywhere from a few microseconds to hours depending on the material): the process then corresponds to either one of two phenomena, depending on the type of transition and hence the wavelength of the emitted optical photon: delayed fluorescence or phosphorescence, also called after-glow.

A scintillation detector or scintillation counter is obtained when a scintillator is coupled to an electronic light sensor such as a photomultiplier tube (PMT) or a photodiode. PMTs absorb the light emitted by the scintillator and reemit it in the form of electrons via the photoelectric effect. The subsequent multiplication of those electrons (sometimes called photo-electrons) results in an electrical pulse which can then be analyzed and yield meaningful information about the particle that originally struck the scintillator. Vacuum photodiodes are similar but do not amplify the signal while silicon photodiodes accomplish the same thing directly in the silicon.

The first device which used a scintillator was built in 1903 by Sir William Crookes and used a ZnS screen. The scintillations produced by the screen were visible to the naked eye if viewed by a microscope in a darkened room; the device was known as a spinthariscope. The technique led to a number of important discoveries but was obviously tedious. Scintillators gained additional attention in 1944, when Curran and Baker replaced the naked eye measurement with the newly developed PMT. This was the birth of the modern scintillation detector.

Read more about Scintillator:  Applications For Scintillators, Implications For Scintillator Development, Properties of Scintillators, List of Inorganic Scintillators

Other articles related to "scintillator, scintillators":

Shashlik (physics)
... lead) and scintillator materials (crystal or plastic) used in calorimetry ... The scintillator material produces visible light when transversed by the particle's radiated energy ... the particle may be then measured by the intensity of scintillation light produced by the various scintillator slices ...
Scintillation Counter - Detection Materials
... The scintillator consists of a transparent crystal, usually a phosphor, plastic (usually containing anthracene) or organic liquid (see liquid scintillation ... Cesium iodide (CsI) in crystalline form is used as the scintillator for the detection of protons and alpha particles ... sodium iodide (NaI) containing a small amount of thallium is used as a scintillator for the detection of gamma waves and Zinc Sulphide is widely used as ...
List of Inorganic Scintillators
... in the UV band (220 nm) and has a 0.7 ns decay time (smallest decay time for any scintillator), while the slow scintillation light is emitted at ... CdWO4 or cadmium tungstate a high density, high atomic number scintillator with a very long decay time (14 μs), and relatively high light output (about 1/3 of ... these crystals are one of the brightest scintillators ...
Telescope Array Project - Surface Detector
... When these particles pass through the plastic scintillator within the detector, it induces photo electrons which are then gathered by wavelength-shifting fibers ... Each scintillation detector layer is made of extruded plastic scintillator that is 1.2 cm thick and has an area of 3m2 ... photo multiplier tube is connected to the scintillator via 96 wavelength-shifting fibers ...
Telescope Array Project - TALE
... The TALE project also has a graded infill array of scintillator stations spaced 400m and 600m apart ... It then connects to the main Telescope Array scintillator array where the scintillator detectors are 1200m apart ...