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

Search for axions from nearby star Betelgeuse comes up empty

The elusive axion particle is many times lighter than an electron, with properties that barely make an impression on ordinary matter. As such, the ghost-like particle is a leading contender as a component of dark matter—a ...

Hard to crack research reveals how crop roots penetrate hard soils

Scientists have discovered a signal that causes roots to stop growing in hard soils which can be 'switched off' to allow them to punch through compacted soil—a discovery that could help plants to grow in even the most damaged ...

Galaxies hit single, doubles, and triple (growing black holes)

When three galaxies collide, what happens to the huge black holes at the centers of each? A new study using NASA's Chandra X-ray Observatory and several other telescopes reveals new information about how many black holes ...

Using neural networks for faster X-ray imaging

A team of scientists from Argonne is using artificial intelligence to decode X-ray images faster, which could aid innovations in medicine, materials and energy.

Image: Cosmic neon lights

This image shows a new type of star that has never been seen before in X-ray light. This strange star formed after two white dwarfs—remnants of stars like our sun—collided and merged. But instead of destroying each other ...

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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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