X-Energo is intended to suite the needs of the students and specialists investigating X-ray propagation and interaction with the substance.
The software consists of three main parts:
- programs for simulation of processes in X-ray spectrometers;
- programs for development of methods of analyses.
Version1.0 of software includes the following programs:
- calculation of the X-ray tubes spectra.
- calculation of filtration of X-ray spectra.( FILTER)
- calculation of the intensity of the main characteristic lines of the fluorescent X-ray spectra of homogeneous samples of an arbitrary sample.(SAMPLE)
- calculation of the output of the detector on the spectra (DETECTOR)
- numerical determination of the spectrometer main analytical characteristics ( ANALYTE)
- spectrometer simulation
- determination of the theoretical coefficient of influence.
- program illustrating the character of analytical line intensity variation depending on analytical element concentration and matrix composition.
X-ray spectra visualization and processing (SPECTRUM EDITOR).
Atomic Constants Reference Data
- 35 most intensive characteristic lines.
- Electron binding energies for K - Q shells.
- Fluorescence yields for K - M levels.
- Relative intensities of main characteristic lines
Cross sections reference in the range of energies 1 - 150 keV.
This program enables to get information on the mass cross sections of the coherent and incoherent scattering and photoabsorption for a sample of an arbitrary composition in the range of energies from 1 to 150 keV.
Using Mendeleev's Periodic Chart, presented on the screen user can build samples, used by other X-Energo simulation programs as well.
After the wanted sample composition is set it is possible to determine the values of integral mass cross sections for this sample. Calculations are possible as in Angstroms, so in keV and user can swap between units during operation.
Four reference regimes are possible:
- Building a table of cross sections for an arbitrary set of wave engths /energies, determined by the user.
- Building table of cross sections for the range of wavelengths / energies with uniform increment.
- Determination of cross sections on the wavelengths of characteristic lines of an element selected by user.
- Determination of cross sections for the wavelengths of emission lines of some isotopes, most commonly used inXRFA.
Chemical Formula Calculator
Chemical Formula Calculator enables to set sample composition not setting it element by element but setting the stuff by chemical formulas in notations commonly used in chemistry. You may input formulas of complicated substances, set concentration of these substances in the sample and in the result will receive elements percentages in the sample. Up to five substances may be set in one sample.
Characteristic lines order reference
̉his reference gives a possibility to analyse the presence of characteristic lines in the neighbourhood of the analytical line. The program provides a set of characteristic lines wavelengths near the analytical and some estimation of these lines relative intensities.
User by different filters may tune the program environment excluding unnecessary lines, elements, orders of diffraction.
The search of a wanted line is possible by its wavelength (energy) or by elements name and line name.
All simulation programs have one common feature - they realise some transformation of X-ray spectra. So X-ray spectra is natural unit of information with which all operations in simulation part of X-Energo are
Spectra in X-Energo are saved in special format *.spc, saving location and the form of the absorption edges. It provides a flexibility of operation with spectra and excludes the loss of qualitative and quantitative information in the result of spectra transformations. *.spc format provides a wide range of different possibilities of spectra presentation in all reasonable forms.
Tube - program for generation of the spectra of an arbitrary X-ray tube. It provides a lot of possibilities of investigation of the X-ray tube spectra and the effect of its form on the final result.
user may vary amount of anode material characteristic lines taken into concideration, select only some portion of continuum.
- four different mathematical models for tube spectra are realised;
- an arbitarary material for anode may be selected;
- variable voltage, window thicknes and other
parameters effecting tube spectra;
X-ray tubes with bulck and thin end anodes may be simulated.
A possibility to simulate a situation when not a full spectra of tube is used for analysis enables to analyse the input of different spectra components into resulting analytical signal.
Filter - is the program for determination of the filtering of the X-ray
spectra by a filter of an arbitrary composition. Determination of the
filter fluorescence characteristic emission due to excitation by the filtered radiation is possible.
Just select spectra to filter, set filter material and thickness, determine where you want to save results and press the start button.
Sample - is the program for simulation of the fluorescence of the sample characteristic radiation under excitation by an arbitrary X-ray spectra. The estimation of the scattered radiation spectra, forming a significant part of the background in the result spectra is realised. Processing of a group of samples is possible.
Several options of calculation regime are introduced which are:
- Secondary excitation - when Off secondary subexcitation of elements by fluorescence radiation is not taken into account.
- Scattering inputs - when On the input into excitation by scattered in the sample radiation is taken into account.
Background determination - when Off only fluorescence of the sample elements are analysed, but when On spectra scattered by sample is determined.
Detector - program for determination of the form of the detector output
on the X-ray spectra.
By means of this program it is possible to simulate the output of the detectors of different types on the incoming spectra and analyse the effect of variation of detector parameters on the form of the output spectra. It also provides a possibility to determine detector efficiency curve.
Three groups of detectors are taken for consideration:
- Gas discharge
For each type of detector it is possible to vary its main design parameters
( thickness, density, material) and manually to set its resolution. It
is also possible to analyse the effect of analyser characteristics (amount
of channels, for example) on the output spectra form.
Each spectra line forms the peak, corresponding to its energy,
peaks of departure and a shelf of continuum. A form of the resulting
spectra of a single characteristic line is presented.
Analyte - is the program for numerical determination of spectrometer main analytical characteristics.
It provides a possibility to make an express estimation of the possibility of solution of the certain analytical problem by means of analytical characteristics on the base of which is made conclusion on the possibility of determination of some element with the required accuracy in a sample of certain composition by means of spectrometer of this or that type.
To begin operation in the program it is necessary to load data on spectrometer characteristics, most of which may be taken from spectrometer Technical Specification or obtained from spectrometer manufacture. They are:
Main Apparatus Error - relative r.m.s. deviation of the indications of a spectrometer (set of pulses or count rate) from average value minus statistical component.
- Contrast - relation of integral sensitivity to a background.
- Integral Sensitivity - analytical signal (count rate) for a sample with unit concentration of the element under determination. The integral sensitivity can be found directly by measurement of a sample composed of a pure element, or can be calculated on the base of the results of measurement of a sample of known composition.
In the result of the operation of the Analyte the following data are determined:
Dr. S.Savelyev and B.Sc. I.Tormina
- Absorption Factor (P) - relation of absorption properties of a matrix for X-ray radiation to absorption properties of a determined element (in view of additional excitation);
- Instrumental reproducibility of the analysis (Reprod.) - component of a random error of the analysis caused by instability of operation of the analytical device (instability of electronic circuits, mechanical motion, etc.);
- Differential Sensitivity (Diff.Sens.) - first derivative from a count rate of an analytical line of a determined element (analytical signal) on its concentration;
- The background count rate (Background) - count rate in the channel of the analysed element in a sample, in which this element is absent;
- Background concentration (Backgr.Conc.) - concentration of a determined element, for which the analytical signal numerically is equal to a background;
- Detection limit (Det. limit) - concentration of the analysed element, which can be determined with the certain confidential probability.
This program enables to carry on numerical investigation of spectrometers of different types. It is possible to get information on spectrometer analytical characteristics and to analyse the influence of variation of some design or operation parameters on analytical characteristics. The program enables to carry on simulation of energy dispersion spectrometers, spectrometers with crystal dispersion elements and spectrometers of special types (with excitation by polarised radiation for example). The program realises determination of spectrometer detector output on the set sample fluorescence under certain excitation. Simultaneously the background is calculated in the same way as the "experimental" background is determined for the set of reference samples in analytical practice. On the base of the calculated background the contrast is determined.
The only parameter that is necessary to be determined in experiment is the value of the Main Apparatus Error, which accumulates the information on spectrometers stability, that is totally determined by device design and manufacturing.
Theoretical Coefficients program is calculating theoretical influence coefficients as in the standard, well known form, so also is possible by means of this program to determine wide range of different relation equations determining the ratio between element concentration and intensity.
This program was developed for the educational purposes and enables analysis of the character of variation of the analytical line intensity via concentration of the analytical element in an arbitrary matrix.
Results are presented in a form of a diagram. Up to five different samples may be presented simultaneously. The main screen of the program is presented.
Last modified April 13, 2000