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.
CsI(Na) or cesium iodide doped with sodium: the crystal is less bright than CsI(Tl), but comparable in light output to NaI(Tl). The wavelength of maximum emission is at 420 nm, well matched to the photocathode sensitivity of bi‑alkali PMTs. It has a slightly shorter decay time than CsI(Tl) (630 ns versus 1000 ns for CsI(Tl)).
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 ...
In plant immunology, the hypersensitive response (HR) is a mechanism used by plants to prevent the spread of infection by microbial pathogens.HR is characterized by the rapid death of cells in the local region surrounding an infection and it serves to restrict the growth and spread of pathogens to other parts of the plant.
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.
Carbon on Earth naturally occurs in two stable isotopes, with 98.9% in the form of 12 C and 1.1% in 13 C. [1] [8] The ratio between these isotopes varies in biological organisms due to metabolic processes that selectively use one carbon isotope over the other, or "fractionate" carbon through kinetic or thermodynamic effects. [1]
The scintillator is the primary radiation sensor that emits light when struck by high energy photons. Gd 2 O 2 S based ceramics exhibit final densities of 99.7% to 99.99% of the theoretical density (7.32 g/cm 3 ) and an average grain size ranging from 5 micrometers to 50 micrometers in dependence with the fabrication procedure. [ 1 ]