Electromagnetic radiation gamma rays

Although the nucleus is normally found in its lowest energy state, it may be produced as the result of a nuclear reaction, or tlirougli radioactivity in a number of excited states whose detailed properties may differ quite markedly from the lowest state, if formed in an excited state, it will decay, normally by the emission of electromagnetic radiation (gamma rays) lo the lowest state, or by the emission of particles to another nucleus. 

In neutron activation analysis, the sample is bombarded with a beam of neutrons, some of which are absorbed into sample nuclei. These sample nuclei are now radioactive. They emit electromagnetic radiation, gamma rays. Each isotope is represented by a specific energy and frequency of gamma ray, which identifies the isotope and, thus, the element. In this method of detecting art forgeries, the sample is not changed and its composition can be accurately assessed. 

There are four types of radiation generally considered when discussing radiation hazards. These are 1) alpha particles, or helium nuclei 2) beta particles, or electrons 3) neutrons and 4) electromagnetic radiation (gamma rays and x-rays). 

The method by which incident radiation interacts with the medium to cause ionization may be direct or indirect. Electromagnetic radiations (x rays and gamma photons) are indirectly ionizing that is, they give up their energy in various interactions with cellular molecules, and the energy is then utilized to produce a... 

Whereas Table 2 presents some radiation terms that are pertinent to the following discussion, Table 3 lists the radioisotopes and their half-lives that are suitable to microautoradiography. Of the two types of nuclear radiation, i.e., wavelike electromagnetic radiation (X-ray and gamma ray) and corpuscular radiation (electrons, beta particles, and alpha particles) the latter are the most employable for microautoradiography. The reader is referred to Slater (20) for in-depth discussion of all aspects of radiobiology. 

Several types of radiation find a sterilizing application in the manufacture of pharmaceutical and medical products, principal among which are accelerated electrons (particulate radiation), gamma-rays and UV light (both electromagnetic radiations). The major target for these radiations is believed to be microbial DNA, with damage occur -... 

Ionizing radiation Particulate radiations (alpha, electron, neutron, proton) and electromagnetic radiations (X-rays and gamma rays) that have the ability to disrupt molecular bonds (ionize) when they interact with matter. 

Radioactive nuclides n. Atoms that disintegrate by emission of corpuscular or electromagnetic radiations. The rays most commonly emitted are alpha or beta or gamma rays. The three classes are primary, which have half-hfe times exceeding 10 years. These may be alpha-emitters or beta-emitters. Secondary, which are formed... 

Thus, the Gray expresses the amount of radiation absorbed by the body and the Sievert takes into account the effect of the radiation on the human body. For electromagnetic radiation (gamma and x-rays), these are considered as equal, that is, a dose of 1 Gy is equivalent to 1 Sv. However, for energetic particles absorbed by the body, the biological effects are more severe, so that a dose of one Gy of radiation by alpha particles would be equivalent to 20 Sv. 

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