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Как работает XRF — рентгеновская флуоресцентная спектроскопия

How XRF Works – X-Ray Fluorescence Spectroscopy

X-ray fluorescence (XRF) is a non-destructive analytical method used to determine elemental concentrations in various materials.

How XRF Works – X-Ray Fluorescence Spectroscopy

X-ray fluorescence (XRF) is a non-destructive analytical method used to determine elemental concentrations in various materials.

LIBS operates by using a pulsed, focused laser that is fired at a sample with sufficient pulse energy as to create a plasma around the area struck. Bound atomic electrons are striped from the atoms comprising the material. As the plasma cools, atoms recombine with electrons and in the process emit light in the UV, optical and IR regimes.

LIBS has been used for more than 30 years as a laboratory technique, capable of analyzing any element in the periodic table. Recently, the technique has been miniaturized into a handheld device (HH LIBS) capable of analyzer any element, depending on the spectrometer range chosen for the device.

Измеряет каждый элемент Периодической таблицы от H to U

 

Атомный уровень

Atom-Basic-Configuration

ONE – All atoms have a fixed number of electrons. These electrons are arranged in orbitals around the nucleus. Energy Dispersive XRF (EDXRF) typically captures activity in the first three electron orbitals, the K, L, and M lines.

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TWO – All atoms have a fixed number of electrons. These electrons are arranged in orbitals around the nucleus. Energy Dispersive XRF (EDXRF) typically captures activity in the first three electron orbitals, the K, L, and M lines.

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THREE – All atoms have a fixed number of electrons. These electrons are arranged in orbitals around the nucleus. Energy Dispersive XRF (EDXRF) typically captures activity in the first three electron orbitals, the K, L, and M lines.

image 27

FOUR – All atoms have a fixed number of electrons. These electrons are arranged in orbitals around the nucleus. Energy Dispersive XRF (EDXRF) typically captures activity in the first three electron orbitals, the K, L, and M lines.

 

The Atomic Level

ONE – All atoms have a fixed number of electrons. These electrons are arranged in orbitals around the nucleus. Energy Dispersive XRF (EDXRF) typically captures activity in the first three electron orbitals, the K, L, and M lines.

ONE – All atoms have a fixed number of electrons. These electrons are arranged in orbitals around the nucleus. Energy Dispersive XRF (EDXRF) typically captures activity in the first three electron orbitals, the K, L, and M lines.

Результаты можно просматривать в виде процентов или в виде спектра. XRF будет обрабатывать (оцифровывать, считать) около 200 000 или более рентгеновских снимков каждую секунду. Эти обнаруженные рентгеновские лучи формируют спектр. Каждый пик в спектре взят из характерного рентгеновского излучения, испускаемого конкретным элементом, таким как Cr или Ni и т. Д. Высота пика пропорциональна концентрации элемента. Высота пика преобразуется в процент или ppm этого элемента с помощью метода калибровки — либо фундаментальных параметров, либо заводских или пользовательских эмпирических калибровок

Interference

Elemental analysis techniques experience interferences that must be corrected or compensated for in order to achieve adequate analytical results. In XRF Spectrometry, the primary interference is from other specific elements in a substance that can influence (matrix effects) the analysis of the element(s) of interest. However, these interferences are well known and documented; and, instrumentation advancements and mathematical corrections in the system’s software easily and quickly correct for them. In certain cases, the geometry of the sample can affect XRF analysis, but this is easily compensated for by selecting the optimum sampling area, grinding or polishing the sample, or by pressing a pellet.

Interference

Elemental analysis techniques experience interferences that must be corrected or compensated for in order to achieve adequate analytical results. In XRF Spectrometry, the primary interference is from other specific elements in a substance that can influence (matrix effects) the analysis of the element(s) of interest. However, these interferences are well known and documented; and, instrumentation advancements and mathematical corrections in the system’s software easily and quickly correct for them. In certain cases, the geometry of the sample can affect XRF analysis, but this is easily compensated for by selecting the optimum sampling area, grinding or polishing the sample, or by pressing a pellet.

1
The x-ray tube irradiates a solid or a liquid sample.
2
An electron in a higher shell fills the K or L level vacancy by emitting energy and “jumping down” to that lower energy level.
3
Atoms in the sample are struck with X-rays of sufficient energy, i.e. greater than the atom’s K or L shell binding energy, causing an electron to be ejected from the K or L shell level of the atom.