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. 

Thus we shall be interested with the following types of radiation gamma rays, beta rays, protons, deutons, alphas, fission fragments, and fast neutrons. 

Gamma rays and X-rays are among the most penetrating types of radiations. Gamma rays are produced in the nuclear reactions that take place in nuclear power plants. They were also associated with the nuclear weapons that were detonated in Hiroshima and Nagasaki, Japan. 

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 -... 

There are two ways in which the compound nucleus can release this excess energy (1) it may radiate gamma rays, or (2) it may emit one or more nuclear particles (neutrons, protons, or alpha particles). Which of these two processes predominates depends on the total excitation energy of the compound nucleus. If sufficient energy is available, more than one reaction can take place. 

Figure 10.8 Effect of nuclear radiation (gamma rays) dosage on...

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