Editing Nuclear technology (section)

===Industrial applications===

Since some ionizing radiation can penetrate matter, they are used for a variety of measuring methods. X-rays and gamma rays are used in [[industrial radiography]] to make images of the inside of solid products, as a means of [[nondestructive testing]] and inspection. The piece to be radiographed is placed between the source and a photographic film in a cassette. After a certain exposure time, the film is developed and it shows any internal defects of the material.

'''Gauges''' - Gauges use the exponential absorption law of gamma rays
*Level indicators: Source and detector are placed at opposite sides of a container, indicating the presence or absence of material in the horizontal radiation path. Beta or gamma sources are used, depending on the thickness and the density of the material to be measured. The method is used for containers of liquids or of grainy substances
*Thickness gauges: if the material is of constant density, the signal measured by the radiation detector depends on the thickness of the material. This is useful for continuous production, like of paper, rubber, etc.

'''Electrostatic control''' - To avoid the build-up of static electricity in production of paper, plastics, synthetic textiles, etc., a ribbon-shaped source of the alpha emitter <sup>241</sup>[[Americium|Am]] can be placed close to the material at the end of the production line. The source ionizes the air to remove electric charges on the material.

'''[[Radioactive tracer]]s''' - Since radioactive isotopes behave, chemically, mostly like the inactive element, the behavior of a certain chemical substance can be followed by ''tracing'' the radioactivity. Examples:
*Adding a gamma tracer to a gas or liquid in a closed system makes it possible to find a hole in a tube.
*Adding a tracer to the surface of the component of a motor makes it possible to measure wear by measuring the activity of the lubricating oil.

'''Oil and Gas Exploration'''- Nuclear [[well logging]] is used to help predict the commercial viability of new or existing wells. The technology involves the use of a neutron or gamma-ray source and a radiation detector which are lowered into boreholes to determine the properties of the surrounding rock such as porosity and lithography.[http://hps.org/publicinformation/radterms/radfact154.html]

'''Road Construction''' - Nuclear moisture/density gauges are used to determine the density of soils, asphalt, and concrete. Typically a cesium-137 source is used.