Using The Obtained Values A Programming Language Such As Labview 71 Is Used To Design Report

1. Calibration carried out for EXDRF and WDXRF
XRF measurement is based on the concept that different elements have characteristic x-rays. The integrity of the XRF measurement is thus tied on the ability to accurately determine the energies of these X-rays. The process of calibration is thus used in assigning distinct energy values for each channel in the panalytical EDXRF and panalytical WDXRF.
We thus do calibration by sending x-rays of known energy values to the detector. Knowledge of the channels where these known values are sorted is then used in assigning values to channels. However, this manual method is not practical. Calibration is thus done by applying curve fitting techniques to six or so channel data points available. Calibration methods include:
i. Linear and Quadratic Approximations

ii. Linear and Cubic Spline Interpolation

iii. Optimization Method

A large number of samples are used for the calibration sample so as to have enough number of peaks for calibration.
2. Interferents and how they can be dealt with.

Interferents are inter-element interactions and wavelength spectral interference.

Spectral interference refers to conditions in which radiations from different analytes hit the detector simultaneously. Use of the less than 300μm filter minimizes wavelength spectral interference.
4. Significance of Compton scatter in XRF Analysis.
The concept behind XRF analysis is that different elements have their different characteristic X-rays. Compton scatter is important in the sense that though some energy is lost by incident X-ray due to scattering of electrons, the total momentum of the electron is preserved. Due to this the wavelength scattered photon rises by this equation Δλ=0.0423(1-cosθ)

Thus the bigger the angle of scatter (θ approaching 90), the bigger the wavelength thus the stronger the detected value and vice-versa.

Reference

Brian, L.F., 2008, X-Ray Fluorescence Instrument Calibration: Theory and Application
Frank, R.F. et al, 1999, Spectral Interference in X-Ray Fluorescence Analysis of Common Materials