Gamma ray

:This article is about electromagnetic radiation. For the power metal band, see Gamma Ray (band)

Uses

The powerful nature of gamma rays have made them useful in the sterilising of medical equipment by killing bacteria. They are also used to kill bacteria in foodstuffs, particularly meat and vegetables, to maintain freshness. This process is known as irradiation. The irradiation of food has become an issue of public debate. Critics claim that the effects of ionizing radiation on food are poorly understood, and that such irradiation may damage the nutritional content of food or form toxic compounds in the food. Supporters argue that the critics are motivated by irrational paranoia about anything to do with radiation, and that the effects of radiation on food have been well studied in the context of our understanding of gamma rays; they also point out that no known process involving gamma rays (as opposed to neutron radiation) results in radioactive activation, and irradiated food may easily be examined for radioactivity. Finally, they point to the health dangers of inadequately preserved foods.

Related Topics:
Bacteria - Irradiation - Ionizing radiation - Neutron radiation

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In spite of their cancer-causing properties, gamma rays are also used to treat some types of cancer. In the procedure called gamma-knife surgery, multiple concentrated beams of gamma rays are directed on the growth in order to kill the cancerous cells. The beams are aimed from different angles to focus the radiation on the growth while minimising damage to the surrounding tissues.

Related Topics:
Cancer - Gamma-knife

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Gamma rays are also used for diagnostic purposes in nuclear medicine. Several gamma-emitting radioisotopes are used, one of which is technetium-99m. When administered to a patient, a gamma camera can be used to form an image of the radioisotope's distribution by detecting the gamma radiation emitted. Such a technique can be employed to diagnose a wide range of conditions (e.g. spread of cancer to the bones).

Related Topics:
Nuclear medicine - Radioisotope - Technetium - Gamma camera

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Gamma ray detectors are also starting to be used in Singapore and Pakistan as part of the Container Security Initiative (CSI). These US$5 million machines are advertised to scan 30 containers per hour. The objective of this technique is to pre-screen merchant ship containers before they enter U.S. ports.

Related Topics:
Container Security Initiative - US$

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