The x-ray fluorescence, also called the XRF, is a process which involves the displacement of electrons from their atomic orbital positions. This, in turn, releases a burst of energy which is characteristic of a particular element. After that, the release of energy is registered by a detector in the XRF instrument, leading to the grouping of energies by element. To understand the workings of an XRF device in detail, here’s what you need to know.
A beam of x-ray with sufficient energy to hamper the electrons in the atom’s inner shell is created by a tube of the x-ray inside the analyzer. As a result, a beam of x-ray is emitted from the front section of the XRF analyzer.
The second step involves the interaction of the x-ray beam with the sample atoms. During this process, the electrons from the atom’s inner orbital shells are displaced due to the energy difference between the binding energy holding the electrons in place and the primary x-ray beam coming from the analyzer. This displacement occurs when the energy from the x-ray beam is stronger than the electrons’ binding energy. Usually, electrons are fixed at particular energies which determine their orbits. It should also be noted that that the spacing between an atom’s orbital shells is unique to each element’s atoms. Therefore, a potassium atom has a different spacing between its shells as opposed to silver or gold atom.
When using an XRF analyzer, it is also important to understand how electron vacancy is filled. Once electrons have been knocked from their orbit, they create vacancies, causing instability. The atom then corrects this instability by filling the vacancies left behind by the displaced electrons. The vacancies are filled when higher orbits move downwards to the lower orbit in the area where the vacancy exists. For instance, if the innermost electron is displaced, an electron from its next shell up moved down to take up the space left behind. This is fluorescence.
The further the electrons are from the nucleus, the higher the binding energies. As a result, an electron loses energy when it falls from higher to a lower electron shell. The energy that is lost during this process is equivalent to the energy difference between the two shells, and this is obtained by the distance between these two shells. For each element, the distance between any two orbital shells is usually unique for every element.
The energy lost in step two can be used in recognizing the element from which it comes from since, as mentioned, the amount of energy that is lost during fluorescence is unique for every element. The quantity in which the individual energies appear is calculated by the instrument to determine the quantity of the present element.
These process usually takes place within a fraction of a second and for that reason, a measurement the XRF handheld gun occurs within seconds as well. However, the actual time needed to measure varies depending on the levels of interest and the nature of the sample. Knowing about the above steps will give you an idea of how a modern XRF handheld gun operates.