Related topics: x rays

Scientists spy unstable semiconductors

Scientists from Cardiff University have, for the first time, spotted previously unseen "instabilities" on the surface of a common compound semiconductor material.

Deadline closing for names to fly on NASA's next Mars rover

It's the final boarding call for you to stow your name on NASA's Mars 2020 rover before it launches to the Red Planet. The Sept. 30 deadline for NASA's "Send Your Name to Mars" campaign gives the mission enough time to stencil ...

Slow electrons to combat cancer

Ion beams are often used today in cancer treatment: this involves electrically charged atoms being fired at the tumour to destroy cancer cells. Although, it's not actually the ions themselves that cause the decisive damage. ...

Stacked graphene layers act as a mirror for electron beams

Stacked layers of graphene can act like a mirror for beams of electrons. Physicists Daniël Geelen and colleagues discovered this using a new type of electron microscope. In an article in Physical Review Letters, they describe ...

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Cathode ray

Cathode rays (also called an electron beam or e-beam) are streams of electrons observed in vacuum tubes, i.e. evacuated glass tubes that are equipped with at least two metal electrodes to which a voltage is applied, a cathode or negative electrode and an anode or positive electrode. They were discovered by German scientist Johann Hittorf in 1869 and in 1876 named by Eugen Goldstein kathodenstrahlen (cathode rays). Electrons were first discovered as the constituents of cathode rays. In 1897 British physicist J. J. Thompson showed the rays were composed of a previously unknown negatively charged particle, which was named electron.

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