File Name: continuous and characteristic x ray spectrum .zip
Bremsstrahlung, for example, accounts for continuous X-ray spectra— i. In generating bremsstrahlung, some electrons beamed at a metal target in an X-ray tube are brought to rest by one head-on collision with a nucleus and thereby have all their energy of motion converted at once into radiation of maximum energy.
Characteristic X-rays are emitted when outer- shell electrons fill a vacancy in the inner shell of an atom , releasing X-rays in a pattern that is "characteristic" to each element.
X-rays , also known as X-radiation , refers to electromagnetic radiation no rest mass, no charge of high energies. X-rays are high-energy photons with short wavelengths and thus very high frequency. The radiation frequency is key parameter of all photons, because it determines the energy of a photon.
X-ray spectra - continuous and characteristic X-ray spectra. The spectrum from an X-ray tube contains two distinct parts :. It consists of radiations of all possible wavelengths, from a certain lower limit to higher values continuously, as in the case of visible light. Origin - Continuous X-ray spectra. X-rays are produced, when high velocity electrons strike the target material of high atomic number. It has also been mentioned in the production of X-rays, that most of the energy of the electrons goes into the heating of the target material. A few fast moving electrons penetrate deep into the interior of the atoms of the target material and are attracted towards the nuclei by the attractive forces of their nuclei.
It has long been known that the x-rays emitted from an x-ray tube contain radiation characteristic of the material of the x-ray target superimposed upon a continuous spectrum. As early as Winkelmann and Straubel had noticed a scattered radiation which was characteristic of fluor spar; and later the characteristic x-rays scattered by different elements were studied systematically in a series of classic researches by Barkla. However, the actual separation of different wave-lengths into a spectrum was not possible until Friedrich , Knipping and Laue showed that crystals act as three dimensional diffraction gratings. Proceeding rapidly on the basis of this discovery W. Bragg and W.
Each type of atom or element has its own characteristic electromagnetic spectrum. In this section, we explore characteristic x rays and some of their important applications. We have previously discussed x rays as a part of the electromagnetic spectrum in Photon Energies and the Electromagnetic Spectrum. That module illustrated how an x-ray tube a specialized CRT produces x rays. Electrons emitted from a hot filament are accelerated with a high voltage, gaining significant kinetic energy and striking the anode.
X-Ray Spectrum – Characteristic and Continuous
Under the assumption that the target of an x-ray tube is a plane mirror which completely reflects the electron waves, the characteristics of the continuous x-ray spectrum are deduced from the principles of wave-mechanics. It is also assumed that the velocity of the electrons is so small that its square may be neglected in comparison to c 2. The radiation due to a single transition is practically unidirectional, the direction of the beam Nadelstrahl being determined by the conservation laws of energy and momentum.
Table of Contents. X-radiation is created by taking energy from electrons and converting it into photons with appropriate energies. This energy conversion takes place within the x-ray tube. The quantity exposure and quality spectrum of the x-radiation produced can be controlled by adjusting the electrical quantities KV , MA and exposure time, S , applied to the tube.
Пока рано, - сказал Стратмор. - Если служба безопасности обнаружит затянувшуюся надолго работу ТРАНСТЕКСТА, перед нами возникнет целый ряд новых проблем. Я хочу уничтожить все следы Цифровой крепости до того, как мы откроем двери. Сьюзан неохотно кивнула.