WDX Wavelength dispersive x-ray

TGA/DTA combined thermogravimetry / differential thermal analysis WDX wavelength-dispersive X-ray diffraction... 

Within this technique, we include EDX (energy dispersive x-ray analysis), WDX (wavelength dispersive x-ray analysis), and XRF (x-ray fluorescence analysis). In all of these, x-rays emitted from a sample are analyzed. In one case, they are created by bombarding the sample with x-rays (XRF), and in the others, they are created by high energy electron beam as in an SEM (EDX, WDX). 

WDX (Wavelength dispersive x-ray) Output data presented as the emitted x-ray wavelength vs. its intensities. ... 

Besides total concentration of multielements, their spatial distribution in samples is also very important in understanding their bioavailability, trophic transfer, and environmental risk. A number of complementary analytical techniques exist for the mapping of elemental distributions in biological tissues including SRXRF (synchrotron radiation X-ray fluorescence) with microbeam (SR-pXRF), microscopic EDX (energy-dispersive X-ray fluorescence), microscopic WDX (wavelength-dispersive X-ray fluorescence), microscopic PIXE (particle-induced X-ray emission), laser ablation ICP-MS, microscopic SIMS (secondary ion mass spectrometry). 

Before the development of semiconductor detectors opened the field of energy-dispersive X-ray spectroscopy in the late nineteen-sixties crystal-spectrometer arrangements were widely used to measure the intensity of emitted X-rays as a function of their wavelength. Such wavelength-dispersive X-ray spectrometers (WDXS) use the reflections of X-rays from a known crystal, which can be described by Bragg s law (see also Sect. 4.3.1.3)... 

Elemental analysis can also be performed on SEM samples using x-ray spectrometer attachments [55], The techniques are known as energy dispersive x-ray (EDX) analysis and wavelength dispersive x-ray (WDX) analysis and require installation of a detector in the sample chamber. 

The wavelength dispersive x-ray (WDX) spectrometer is based on the Bragg law and employs curved crystals that can be rotated so as to reflect the x-rays emitted by the specimen and focus them, one wavelength at a time, onto a detector. Although this technique allows high resolution of one wavelength from another, it has a number of practical disadvantages ... 

In order to individually analyze the fluorescent X-rays from each element, the spectral separation of the X-rays is required. There are two types of spectrographic methods for XRF. They are wavelength dispersive X-ray spectrometry (WDS, WDX) and energy dispersive X-ray spectrometry (EDS, EDX). The characteristics of WDS and EDS are shown in Table 1. Please refer to the following reference for more detailed explanations of XRF [1]. 

The scanning electron microscope (SEM) (XL30 PHILIPS) was used to characterize the surface morphology of deposits. The wavelength-dispersive X-ray (WDX) analysis( 3PC, Microspec Ltd., USA) was used to exist metallic particles over surface Cu-Ni-P alloy plated fabrics. 

If local materials analysis or concentration profiles are necessary, EDX analysis can be carried out as dot, line, or area analysis. In some cases, wavelength-dispersive X-ray (WDX) analysis can also be conducted, for example, to verify whether a phase consists of minimal amounts of Cr, or whether the Cr Kai Hne overlaps with the La L/32 line from the cathode material. 

Fig. 4.21. Schematic diagram of spectrometer arrangements for wavelength-dispersive and energy-dispersive X-ray spectroscopy (WDXS/EDXS) in electron microscopy.

Fig. 7.17. Basic components of the apparatus used for the measurement of X-ray fluorescence by the wavelength and energy dispersive methods.WDX X-rays from the source (A) are allowed to impinge on the sample (B) the resulting XRF is discriminated by the crystal (C), and finally measured by the detector (D). EDX X-rays from the source (A) are allowed to impinge on the sample (B), and the resulting XRF is measured by the detector (D).

Other analytical methods can also be applied for the detection of F in archaeological artefacts, especially when it is possible to take a sample or to perform microdestructive analysis. These are namely the electron microprobe with a wavelength-dispersive detector (WDX), secondary ion mass spectrometry (SIMS), X-ray fluorescence analysis under vacuum (XRF), transmission electron or scanning electron microscopy coupled with an energy-dispersive detector equipped with an ultrathin window (TEM/SEM-EDX). Fluorine can also be measured by means of classical potentiometry using an ion-selective electrode or ion chromatography. 

Electron probe microanalysis (EPMA), X-ray analysis (energy dispersive, EDX, or wavelength dispersive, WDX), and X-ray fluorescence spectroscopy (XRF) are... 

An SEM is usually equipped with an X-ray detector (allowing energy dispersive analysis of X-rays, EDX or wavelength dispersive analysis, WDX). Thus, the characteristic signal X-ray emission of a particular element can be displayed on the imaging screen, and the distribution of different elements on a surface can be readily obtained. Figure 1.26 reveals the origin of particles on a polymer surface with the help of EDX. 

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