Search results
Results from the WOW.Com Content Network
An important application of caesium iodide crystals, which are scintillators, is electromagnetic calorimetry in experimental particle physics.Pure CsI is a fast and dense scintillating material with relatively low light yield that increases significantly with cooling, [11] and a fairly small Molière radius is 3.5 cm.
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 scintillation process is the same as described for organic crystals (above); what differs is the mechanism of energy absorption: energy is first absorbed by the solvent, then passed onto the scintillation solute (the details of the transfer are not clearly understood). [36]
This is another mechanism of phosphor degradation. The scintillation process in inorganic materials is due to the electronic band structure found in the crystals . An incoming particle can excite an electron from the valence band to either the conduction band or the exciton band (located just below the conduction band and separated from the ...
Another application of thallium doping is the sodium iodide and cesium iodide crystals in gamma radiation detection devices. In these, the sodium iodide crystals are doped with a small amount of thallium to improve their efficiency as scintillation generators. [53] Some of the electrodes in dissolved oxygen analyzers contain thallium. [9]
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.
There are two main disadvantages to this scintillator; one being the hexagonal crystal structure, which emits only optical translucency and low external light collection at the photodiode. The other disadvantage is the high X-ray damage to the sample. [2] Terbium-activated gadolinium oxysulfide is frequently used as a scintillator for x-ray ...
Researchers can combine information from several layers of this tracker to determine the path of the particles. After passing through the tracker, the particles enter the calorimeter, which consists of a stack of caesium iodide scintillator crystals to measure the total energy of the particles. The LAT's field of view is large, about 20% of the ...