Related topics: black holes · radiation · wavelength · protein · laser

A fast and precise look into fiber-reinforced composites

Researchers at the Paul Scherrer Institute PSI have improved a method for small angle X-ray scattering (SAXS) to such an extent that it can now be used in the development or quality control of novel fiber-reinforced composites. ...

NICER catches record-setting X-ray burst

NASA's Neutron star Interior Composition Explorer (NICER) telescope on the International Space Station detected a sudden spike of X-rays at about 10:04 p.m. EDT on Aug. 20. The burst was caused by a massive thermonuclear ...

X-rays of human skull to improve military helmets

Scientists often use complex computer models of the skull and brain when designing helmets to prevent or minimize injury to the head due to impact. These models require intricate knowledge of the behavior of the skull and ...

Malaria pathogen under the X-ray microscope

Malaria is one of the most threatening infectious diseases in the world. An international team has now been able to investigate malaria pathogens in red blood cells in vivo using the BESSY II X-ray microscope and the ALBA ...

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X-ray

X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 10 to 0.01 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3 × 1016 Hz to 3 × 1019 Hz) and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays. In many languages, X-radiation is called Röntgen radiation after Wilhelm Conrad Röntgen, who is generally credited as their discoverer, and who had called them X-rays to signify an unknown type of radiation.:1-2

X-rays are primarily used for diagnostic radiography and crystallography. As a result, the term X-ray is metonymically used to refer to a radiographic image produced using this method, in addition to the method itself. X-rays are a form of ionizing radiation and as such can be dangerous.

X-rays from about 0.12 to 12 keV are classified as soft X-rays, and from about 12 to 120 keV as hard X-rays, due to their penetrating abilities.

The distinction between X-rays and gamma rays has changed in recent decades. Originally, the electromagnetic radiation emitted by X-ray tubes had a longer wavelength than the radiation emitted by radioactive nuclei (gamma rays). So older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10−11 m, defined as gamma rays. However, as shorter wavelength continuous spectrum "X-ray" sources such as linear accelerators and longer wavelength "gamma ray" emitters were discovered, the wavelength bands largely overlapped. The two types of radiation are now usually defined by their origin: X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus.

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