Ad
related to: beam detector definition chemistry example answer worksheetstudy.com has been visited by 100K+ users in the past month
Search results
Results From The WOW.Com Content Network
An optical beam smoke detector is a device that uses a projected beam of light to detect smoke across large areas, [1] typically as an indicator of fire. [2] They are used to detect fires in buildings where standard point smoke detectors would either be uneconomical [ 3 ] or restricted for use by the height of the building.
Once the ion beam has ionized target sample atoms, the sample ions are recoiled toward the detector. The beam ions are scattered at an angle that does not permit them to reach the detector. The sample ions pass through an entrance window of the detector, and depending on the type of detector used, the signal is converted into a spectrum.
Ion beam analysis works on the basis that ion-atom interactions are produced by the introduction of ions to the sample being tested. Major interactions result in the emission of products that enable information regarding the number, type, distribution and structural arrangement of atoms to be collected.
In this region, a beam of light crosses the column of analyte and the scattering of light is measured by a photodiode or photomultiplier tube. The detector's output is non-linear across more than one order of magnitude and proper calibration is required for quantitative analysis.
Within the machine the transducer that detects fluorescence created from the upper beam is located a distance away from the sample and at a 90-degree angle from the incident, upper beam. The machine is constructed like this to decrease the stray light from the upper beam that may strike the detector. The optimal angle is 90 degrees.
As the diagram on the right shows, the gallium (Ga+) primary ion beam hits the sample surface and sputters a small amount of material, which leaves the surface as either secondary ions (i+ or i−) or neutral atoms (n 0). The primary beam also produces secondary electrons (e −). As the primary beam rasters on the sample surface, the signal ...
For example, they are used in astronomy to analyze the radiation from objects and deduce their chemical composition. The spectrometer uses a prism or a grating to spread the light into a spectrum. This allows astronomers to detect many of the chemical elements by their characteristic spectral lines.
Cherenkov threshold detectors have been used for fast timing and time of flight measurements in particle detectors. More elaborate designs use the amount of light produced. Recording light from both primary and secondary particles, for a Cherenkov calorimeter the total light yield is proportional to the incident particle energy.