Analytical instrument and principle of XRF-WDX

Principle

X-rays fluorescence which generated from a sample are parallelized by a slit and are entered to the crystal at a fixed angle. The angle of the crystal is changed continuously, and X-ray diffraction intensity is measured by a detector. In X-ray fluorescence spectrum, the vertical axis corresponds to the unit of diffraction angle θ and horizontal axis corresponds to the unit of X-ray intensity._The spectrum suggests the kind and the rough content of element.

Lower limit of detection is about 0.01 % to 0.1 % and detectable elements are ₉F – ₉₂ U.

The principle of XRF-WDX

When an atom is exposed to X-rays, an electron is flipped off from an inner orbital.

Then an outer shell electron falls to a lower orbital.

The X-rays (X-ray fluorescence) corresponding to the energy difference of the two orbitals are released.

Because it is characteristic in the element, the kind of element identified by these characteristic X-rays.

                                 Fig. 1　Overall outline of XRF-WDX                                        Fig.2　Sample holder

The irradiated area of X-rays are limited by the size of sample holder (10 mmφ, 20 mmφ, and 30 mmφ)

Maximum sample size : 45 mm in diameter, 40 mm in height

Fig.3　XRF-WDX  (ZSX Primus Ⅱ (RIGAKU))

Applications

• Analysis of the major element in a substance
• Quantitative analysis of SiO₂ and Al₂O₃ ceramics  (A glass bead is prepared and measured.)
• Analysis of the element of granular materials  (A press mold is prepared and measured.)