{"id":26654,"date":"2020-03-04T09:18:33","date_gmt":"2020-03-04T09:18:33","guid":{"rendered":"http:\/\/sitepourvtc.com\/?page_id=26654"},"modified":"2023-07-14T07:32:52","modified_gmt":"2023-07-14T07:32:52","slug":"detection-of-x-rays-detector-of-x-rays","status":"publish","type":"page","link":"https:\/\/sitepourvtc.com\/nuclear-engineering\/radiation-detection\/detectors-of-ionization-radiation\/detection-of-x-rays-detector-of-x-rays\/","title":{"rendered":"Detection of X-Rays – Detector of X-Rays"},"content":{"rendered":"
Detection of X-rays<\/strong> is very specific because high-energy photons interact differently with the matter. High-energy photons can travel thousands of feet in the air and easily pass through various materials. Moreover, high-energy photons can ionize atoms indirectly and directly (despite they are electrically neutral) through the photoelectric effect <\/strong>and the Compton effect<\/strong>. But secondary (indirect) ionization is much more significant.<\/p>\n To describe the principles of detecting high-energy photons, we must understand the interaction of radiation with matter<\/a>. Each type of particle interacts differently; therefore, we must describe interactions of high-energy photons (radiation as a flow of these rays) separately.<\/p>\n See also: X-Rays<\/a><\/p>\n Although many possible interactions are known, there are three key interaction mechanisms with the matter. The strength of these interactions depends on the X-rays’ energy <\/b>and the material’s elemental composition. Still, not much on chemical properties, since the X-ray photon energy is much higher than chemical binding energies. The photoelectric absorption dominates at low-energies of X-rays,\u00a0<\/strong>while Compton scattering dominates at higher energies.<\/p>\n The photon is completely absorbed in the photoelectric effect, while only partial energy is deposited in any given Compton scattering. The probability of photoelectric absorption (dominates at lower X-rays energies) per unit mass is approximately proportional to:<\/p>\n \u03c4<\/strong>(photoelectric)<\/strong> = constant x Z<\/strong>N<\/sup><\/strong>\/E<\/strong>3.5<\/sup><\/strong><\/p>\n where Z<\/strong> is the atomic number, and the exponent n<\/strong> varies between 4 and 5. E<\/strong> is the energy of the incident photon. The probability of Compton scattering per one interaction with an atom increases linearly with atomic number Z because it depends on the number of electrons available for scattering in the target atom.<\/p>\n Detectors<\/strong> may also be categorized according to sensitive materials and methods that can be utilized to make a measurement:<\/p>\nInteraction of X-rays with Matter<\/h2>\n
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Detectors of X-Rays<\/h2>\n