GC: n

CT: Gamma radiation is one of the three types of natural radioactivity. Gamma rays are electromagnetic radiation, like X-rays. The other two types of natural radioactivity are alpha and beta radiation, which are in the form of particles. Gamma rays are the most energetic form of electromagnetic radiation, with a very short wavelength of less than one-tenth of a nanometer.
Gamma radiation is the product of radioactive atoms. Depending upon the ratio of neutrons to protons within its nucleus, an isotope of a particular element may be stable or unstable. When the binding energy is not strong enough to hold the nucleus of an atom together, the atom is said to be unstable. Atoms with unstable nuclei are constantly changing as a result of the imbalance of energy within the nucleus. Over time, the nuclei of unstable isotopes spontaneously disintegrate, or transform, in a process known as radioactive decay. Various types of penetrating radiation may be emitted from the nucleus and/or its surrounding electrons. Nuclides which undergo radioactive decay are called radionuclides. Any material which contains measurable amounts of one or more radionuclides is a radioactive material.

S: NDT – https://bit.ly/1WA5wXU (last access: 12 December 2018)

N: 1. – gamma (n): third letter of the Greek alphabet, c. 1400, from Greek gamma, from Phoenician gimel, said to mean literally “camel” and to be so called for a fancied resemblance of its shape to some part of a camel. Gamma rays (1903) originally were thought to be a third type of radiation, but later were found to be very short X-rays.
– radiation (n): mid-15c., “act or process of radiating,” from Middle French radiation and directly from Latin radiationem (nominative radiatio) “a shining, radiation,” noun of action from past participle stem of radiare “to beam, shine, gleam; make beaming,” from radius “beam of light; spoke of a wheel”. Meaning “rays or beams emitted” is from 1560s. Meaning “divergence from a center” is 1650s.
2. As a noun:

• the 3rd letter of the Greek alphabet;
• the degree of contrast of a developed photographic image or of a video image;
• a unit of magnetic flux density equal to one nanotesla;
• GAMMA RAY;
• MICROGRAM.

As an adjective:

• of, relating to, or being one of three or more closely related chemical substances
• third in position in the structure of an organic molecule from a particular group or atom —symbol γ.

3. In the fields of Electromagnetic Radiation, Radiological Physics (Theory and Application) and Remote Sensing:

• Electromagnetic radiation, of very short wavelength (of order 10-6 to 10-4 µm) and great penetrative power, which is emitted during the disintegration of many radioactive elements.
• gamma ray: term usually used in the plural (gamma rays).
• gamma ray: term officially approved by the RADARSAT-2 Terminology Approval Group (RTAG).
• gamma-radiation: term standardized by ISO in 1997.
• gamma radiation: term extracted from the “Glossaire de l’énergie nucléaire” and reproduced with permission of the Organisation for Economic Co-operation and Development.

4. In the fields of Compartment – Canadian Nuclear Safety Commission, Electromagnetic Radiation and Radiological Physics (Theory and Application):

• Penetrating electromagnetic radiation emitted by an atomic nucleus during radioactive decay …
• gamma radiation: This type of radiation has greater penetrating power than medical X-rays, and is often used in fixed and portable nuclear gauge.
• gamma ray: term usually used in the plural (gamma rays).

S: 1. OED – https://bit.ly/2EtuEP4; https://bit.ly/2QrwHt7 (last access: 12 December 2018). 2. MW – https://bit.ly/2C5RidS (last access: 12 December 2018). 3 & 4. TERMIUM PLUS – https://bit.ly/2BcZ583 (last access: 12 December 2018).

OV: gamma-radiation

S: TERMIUM PLUS – https://bit.ly/2BcZ583 (last access: 12 December 2018)

SYN: gamma ray

S: TERMIUM PLUS – https://bit.ly/2BcZ583 (last access: 12 December 2018)

CR: lepton , neutrino , nuclear energy, quark , radioactivity, X-rays.