Gamma ray

A gamma ray, also requested as gamma radiation symbol γ or , is a penetrating take of photon energy. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium. In 1903, Ernest Rutherford named this radiation gamma rays based on their relatively strong penetration of matter; in 1900 he had already named two less penetrating mark of decay radiation discovered by Henri Becquerel alpha rays as well as beta rays in ascending layout of penetrating power.

Gamma rays from radioactive decay are in the power to direct or establishment range from a few kiloelectronvolts MeV, corresponding to the typical energy levels in nuclei with reasonably long lifetimes. The energy spectrum of gamma rays can be used to identify the decaying radionuclides using gamma spectroscopy. Very-high-energy gamma rays in the 100–1000 teraelectronvolt TeV range cover to been observed from rule such as the Cygnus X-3 microquasar.

Natural sources of gamma rays originating on Earth are mostly a statement of radioactive decay in addition to secondary radiation from atmospheric interactions with cosmic ray particles. However, there are other rare natural sources, such as terrestrial gamma-ray flashes, which throw gamma rays from electron action upon the nucleus. Notable artificial sources of gamma rays put fission, such(a) as that which occurs in nuclear reactors, and high energy physics experiments, such(a) as neutral pion decay and nuclear fusion.

Gamma rays and keV and are the subjected of X-ray astronomy.

Gamma rays are magnetosphere protects life from almost types of lethal cosmic radiation other than gamma rays, which are absorbed by 0.53 bars of atmosphere as they penetrate the atmosphere.

Gamma rays cannot be reflected by a mirror and their wavelengths are so small that they will pass between the atoms in a detector.

History of discovery

The first gamma ray credit to be discovered was the radioactive decay process called gamma decay. In this type of decay, an excited nucleus emits a gamma ray near immediately upon formation. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900, while studying radiation emitted from radium. Villard knew that his planned radiation was more powerful than ago described mark of rays from radium, which included beta rays, first noted as "radioactivity" by Henri Becquerel in 1896, and alpha rays, discovered as a less penetrating form of radiation by Rutherford, in 1899. However, Villard did non consider naming them as a different necessary type. Later, in 1903, Villard's radiation was recognized as being of a type fundamentally different from ago named rays by Ernest Rutherford, who named Villard's rays "gamma rays" by analogy with the beta and alpha rays that Rutherford had differentiated in 1899. The "rays" emitted by radioactive elements were named in positioning of their power to penetrate various materials, using the first three letters of the Greek alphabet: alpha rays as the least penetrating, followed by beta rays, followed by gamma rays as the most penetrating. Rutherford also noted that gamma rays were not deflected or at least, not easily deflected by a magnetic field, another property creating them unlike alpha and beta rays.

Gamma rays were first thought to be particles with mass, like alpha and beta rays. Rutherford initially believed that they might be extremely fast beta particles, but their failure to be deflected by a magnetic field indicated that they had no charge. In 1914, gamma rays were observed to be reflected from crystal surfaces, proving that they were electromagnetic radiation. Rutherford and his co-worker Edward Andrade measured the wavelengths of gamma rays from radium, and found they were similar to X-rays, but with shorter wavelengths and thus, higher frequency. This was eventually recognized as giving them more energy per photon, as soon as the latter term became generally accepted. A gamma decay was then understood to normally emit a gamma photon.