Revision:X-Rays

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Wavelength: 10^-11m to 10^-9m

Sources

The bombardment of targets of heavy atoms (typically tungsten) by fast moving electrons causes energy levels in the target to change. When the target atoms' excited electrons drop back to their original level, they release fixed quanta of electromagnetic energy. (This is called the photoelectric effect). Basically, X-rays are produced whenever electrons are rapidly brought to rest by matter, however only < 0.5% of the electron's kinetic energy gets converted into these X-rays.

Detection

Photographic plates, fluorescence of certain chemicals (eg, barium platnocyanide), ionization chambers (similar to Geiger counters but at a higher pressure).

Uses

The most well known use of X-rays is for medical scans. These are commonly known as “x-rays”, this, of course, is incorrect since this is the name of the wave not the method. The method is really called radiography or X-ray photography. This form of detection uses it's fluorescence property.

Another use of X-rays in the medical profession is the use of short wavelength X-rays in a fashion similar to gamma rays for the killing of cancerous cells.

Radiography is also used in industry for the examining of potentially damaged machinery to ascertain the cause of any difficulties, or to verify castings or welded joints prior to distribution.

X-Rays are also used with Bragg diffraction.

Notes

There is no difference between the longest wavelength gamma rays and shortest wavelength X- rays (10^-11m). Which name is used usually depends on source and use. X-rays were so called because at first their nature was unknown, for some reason the name stuck once it's nature had been discovered. Short wavelength X-rays are called hard X-rays, long wavelength X-rays are called soft X-rays. X-rays -- just like all electromagnetic rays -- are not deflected by electric or magnetic fields, and it can thus be deduced that they do not carry a charge.

When X-rays come into contact with atoms they may ionize them (this is cause by the electromagnetic wave's strong electric field). This is why X-rays can be detected in ionization chambers.

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