Production
The commonly used radioisotopes have short half lives and so do not occur in nature. They are produced by nuclear reactions. One of the most important processes is absorption of a neutron by an atomic nucleus, in which the mass number of the element concerned increases by 1 for each neutron absorbed. For example,
- 13C + n → 14C
In this case the atomic mass increases, but the element is unchanged. In other cases the product nucleus is unstable and decays, typically emitting protons, electrons( beta particle) or alpha particles. When a nucleus loses a proton the atomic number decreases by 1. For example,
- 32S + n → 32P + p
Neutron irradiation is performed in a nuclear reactor, so tracer studies are carried out close to the reactor itself. The other main method used to synthesize radioisotopes is proton bombardment. The proton are accelerated to high energy either in a cyclotron or a linear accelerator.
Read more about this topic: Radioactive Tracer
Famous quotes containing the word production:
“An art whose limits depend on a moving image, mass audience, and industrial production is bound to differ from an art whose limits depend on language, a limited audience, and individual creation. In short, the filmed novel, in spite of certain resemblances, will inevitably become a different artistic entity from the novel on which it is based.”
—George Bluestone, U.S. educator, critic. “The Limits of the Novel and the Limits of the Film,” Novels Into Film, Johns Hopkins Press (1957)
“From the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.”
—Charles Darwin (1809–1882)
“By bourgeoisie is meant the class of modern capitalists, owners of the means of social production and employers of wage labor. By proletariat, the class of modern wage laborers who, having no means of production of their own, are reduced to selling their labor power in order to live.”
—Friedrich Engels (1820–1895)