X-Ray is penetrating electromagnetic radiation, having a shorter wavelength than light, and produced by bombarding a target, usually made of tungsten, with high-speed electrons. X-rays were discovered accidentally in 1895 by the German physicist Wilhelm Conrad Roentgen while he was studying cathode rays in a high-voltage, gaseous-discharge tube. Despite the fact that the tube was encased in a black cardboard box, Roentgen noticed that a barium-platinocyanide screen, inadvertently lying nearby, emitted fluorescent light whenever the tube was in operation. After conducting further experiments, he determined that the fluorescence was caused by invisible radiation of a more penetrating nature than ultraviolet rays. He named the invisible radiation “X ray” because of its unknown nature. Subsequently, X-rays were known also as Roentgen rays in his honor (Joseph, 2003).
The main use of X-rays is in medicine. A common application is in the form of X-ray machines, which take photos of a patient’s body (Joseph, 2003). If an arm or leg were broken for example, then this limb would be put in front of the X-ray with a piece of photographic film behind. The X –ray is turned on briefly and goes through to the film. The rays go through the skin and flesh easily, showing up as dark areas on the film, but with more difficulty through bone. They are slowed down and so these areas are much lighter. X-rays can also be used to kill cancer cells, but also kill healthy cells, so must be used with much care (Suryanarayana, 1998).
Uses in Medicine
X-ray photographs, called radiographs and fluoroscopy are used extensively in medicine as diagnostic tools. In radiotherapy, X-rays are used to treat certain diseases, notably cancer, by exposing tumors to X-radiation.
The use of radiographs for diagnostic purposes was inherent in the penetrating properties of X-rays.
