GC: n
CT: X-rays are a form of electromagnetic radiation, similar to visible light. Unlike light, however, x-rays have higher energy and can pass through most objects, including the body. Medical x-rays are used to generate images of tissues and structures inside the body. If x-rays travelling through the body also pass through an x-ray detector on the other side of the patient, an image will be formed that represents the “shadows” formed by the objects inside the body.
S: NIH – https://bit.ly/2jhVI5o (last access: 23 December 2018).
N: 1. Translation of German X-strahl. From X (algebraic symbol for an ‘unknown quantity’) + Strahl (‘beam’, ‘ray’). Coined in 1895 by German scientist Wilhelm Conrad Röntgen (1845-1923), who discovered them.
2. A photon of electromagnetic radiation of very short wavelength, ranging from about 10 down to 0.01 nanometers, and very high energy, ranging from about 100 up to 100,000 electron volts.
3. X-rays are produced by accelerating (or decelerating) charged particles; examples include:
- a beam of electrons striking a metal plate in an X-ray tube, or
- a circulating beam of electrons in a synchrotron particle accelerator or storage ring.
Highly excited atoms can emit X-rays with discrete wavelengths characteristic of the energy level spacings in the atoms.
4. X-rays are a form of ionizing radiation. When interacting with matter, they are energetic enough to cause neutral atoms to eject electrons. Through this ionization process the energy of the X-rays is deposited in the matter. When passing through living tissue, X-rays can cause harmful biochemical changes in genes, chromosomes, and other cell components.
5. X-rays (astronomy). Celestial sources of X-rays include close binary systems containing black holes or neutron stars. Additionally, supermassive black holes at the centers of spiral galaxies can emit X-rays as they absorb stars and gas clouds that fall within their gravitational reach.
X-ray telescopes use low-angle reflections to focus these high-energy photons (light) that would otherwise pass through normal telescope mirrors. Because Earth’s atmosphere blocks most X-rays, observations are typically conducted using high-altitude balloons or orbiting telescopes.
6. X-rays (therapy and diagnose).
- Radiation therapy uses high-energy radiation to kill cancer cells by damaging their DNA. The radiation dose used for treating cancer is much higher than the radiation dose used for diagnostic imaging.
- X-ray radiography detects bone fractures, certain tumors and other abnormal masses, pneumonia, some types of injuries, calcifications, foreign objects, dental problems. Examples:
- Mammography
- CT (computed tomography)
- Fluoroscopy
7. Cultural Interrelation: We can mention The Man with the X-ray Eyes (1963), a science-fiction horror film written by Ray Russell and Robert Dillon and directed by Roger Corman.
S: 1. DICTIONARY.com – https://bit.ly/2Fky5HB (last access: 23 December 2018). 2. AHD – https://bit.ly/2QrpEMt (last access: 23 December 2018). 3 & 4. EncBrit – https://bit.ly/2GXy6U9 (last access: 23 December 2018). 5. LIVESCIENCE – https://bit.ly/2qBsnId (last access: 23 December 2018). 6. NIH – https://bit.ly/2jhVI5o (last access: 23 December 2018). 7. BBC – https://bbc.in/2Rfxf5U (last access: 10 January 2019).
SYN: X-radiation, roentgen rays, Röntgen rays.
S: TERMIUM PLUS – https://bit.ly/2QvPtL5 (last access: 8 January 2019).
CR: atom, electricity, electromagnetic wave, electron , gamma radiation, ion , linear accelerator, muon , neutrino , nuclear energy, particle, photonics, radioactive contamination, radioactivity, synchrotron.
