The FP (fundamental parameters) algorithm is an effective method for X-ray fluorescence spectrometry analysis. It can perform qualitative and quantitative analysis on the elemental composition of the sample with little or no standard sample and can also analyze the thickness of the plating or coating.

       It is well known that the biggest problem in X-ray fluorescence analysis is that elemental fluorescence intensity is affected by coexisting elements (matrix absorption and enhancement effects) and is not usually linear with the content. In the calculation of the spectrum, the fundamental parameters algorithm has taken into account the matrix effect, and the linear relationship between the calculated content and the known content can be obtained. A small number of known samples are used to correct the algorithm to remove systematic errors, which can achieve accurate quantitative purposes.

 

1, through the X-ray tube structural parameters, tube flow, tube pressure, etc., to calculate the X-ray tube exit of the original spectrum;
 

2. Based on the structure of the crystal diffraction monochromator (or filter) used, calculate the distribution of the X-ray spectrum incident on the sample;
 

3. The X-rays incident on the sample interact with the elements contained in the sample to calculate the fluorescent X-rays generated when the elements are excited;
 

4. The fluorescent X-ray emitted from the sample enters the detector and the energy spectrum of the final output of the detector is calculated according to the corresponding function of the medium of the detector and the detector.

1. Test the unknown sample to obtain the distribution of the fluorescence intensity of the elements in the sample. Calculate the X-ray energy spectrum according to the solution algorithm and the initial values of the initial elements.
 

2. Calculate the amount of adjustment based on the difference between calculated and measured intensities to obtain the adjusted values for each element, and then calculate a new X-ray energy spectrum.
 

3. Repeat step 2 until the difference between the calculated intensity of the characteristic X-rays of each element and the measured intensity is less than a certain set value, and the iteration ends;
 

4. At the end of the iteration, the calculated spectrum and the measured spectrum are basically coincident, and the quantitative results of the element content in the unknown sample are obtained;