X-rays are used in many ways to image and analyze objects. A very important property of X-rays is their ability to penetrate matter, a fact that allows X-rays to be used to analyze also the interior of objects. Compared to visible light, the much shorter wavelength of X-rays fundamentally allows imaging and analysis at a much better resolution, even down to the atomic length scale.
Here, we briefly introduce some X-ray techniques, describe their potentials and the requirements on the equipment. The techniques have been divided in three categories, Imaging, Spectroscopy & Fluorescence and Scattering & Diffraction.
Imaging is the first historic application using X-rays, as demonstrated already by W. C. Röntgen, and remains the most common application especially due to its wide use for medical imaging. Since the first X-ray image in 1895, an enormous development of X-ray equipment has taken place. Even though most imaging done today uses the same method as Röntgen did, the image quality has become far better thanks to the improved sources and detectors. Nowadays, X-ray imaging is also widely used in various other fields, from industrial inspection & metrology to academic research.
Methods based on scattering and diffraction utilize the radiation that changes direction when interacting with the object. This typically provides information on length scales smaller than what can be directly imaged. In small angle X-ray scattering, bulk samples are analyzed to obtain information about sizes, shapes and orientations of internal structures. The analyzed features are mostly in the size range 1-200 nm. For structures down to the atomic scale, X-ray diffraction is a very powerful technique to analyze crystalline samples. For example, the atomic structures of entire proteins can be resolved.
Spectroscopic X-ray methods build on the dependence on X-ray energy. This dependence can be used to identify elements since every element has its unique absorption edges and fluorescence lines.This provides a way to detect most elements in the periodic table even inside an object and at very low concentrations. X-ray spectroscopy and fluorescence is used in many fields, such as material science, biology, forensics, environmental science and industrial applications.
The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept", you are consenting to this.