Radioactive emissions penetrating power

Figure 23.7 Penetrating power of radioactive emissions. Penetrating power is often measured in terms of the depth of water that stops 50% of the incoming radiation. (Water is the main component of living tissue.) Alpha particles, with the highest mass and charge, have the lowest penetrating power, and 7 rays have the highest. (Average values of actual penetrating distances are shown.)...

The nuclear reactor also must be shielded against the emission of radioactive material to the external environment. Suitable radiation controls include both thermal and biological shielding systems. Radiation from alpha particles (a rays) and beta particles ((3 rays) has little penetrating power, but gamma rays have deep penetration properties. Neutron radiation is, however, the primary area of risk. Typically, extremely thick concrete walls are used as a neutron absorber, but lead-lined concrete and special concretes are also used. 

The emission of nuclear particles or radiation from an isotope during its disintegration is commonly referred to as radioactivity. These emissions are classified as of the three basic types a, 0 and y. a-Particles, which are helium nuclei, have only weak penetrating power and may be stopped by 5-10 cm of air or thin metallic sheets. They are, however, highly energetic, ranging from 4 to 10 MeV. Thus they have a high ionization capacity... 

There are many applications of radiochemistry in industry and engineering. When great precision is required in the manufacture of strips or sheets of metal of definite thicknesses, the penetrating powers of various kinds of radioactive emissions are utilized. The thickness of the metal is correlated with the intensity of radiation passing through it. The flow... 

The identity and symbol of the daughter nuclide of any positron emission is determined in a manner similar to alpha and beta decay, as shown in Example 17.3. Positron emission is similar to beta emission in its ionizing and penetrating power. Table 17.1 summarizes the different kinds of radioactivity that we have covered in the chapter. 

Compare the three forms of radioactive emissions in terms of mass number, electrical charge, and penetrating power. 

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