2015 Nov

Physics of Radiation

November 20, 2015

Physics of Radiation

Radiation is essentially a form of energy that passes through space and/or certain materials and can be classified into two major groups: ionizing and non-ionizing. Ionizing radiation describes high amounts of energy being released from a source, having the potential to ionize (move the electrons) atoms. In contrast, non-ionizing radiation describes low amounts of energy – being insufficient to ionize atoms. Radiation can also be further classified into sub-categories, including: electromagnetic (EM) radiation, background radiation, and particulate radiation, all of which are taught during our Physics tuition classes.

Electromagnetic radiation

This type of radiation is emitted by electromagnetic activity, such as towers releasing radio waves. It is produced when particles, specifically charged, are accelerated. They then form waves which are able to interact and “relay” their qualities to matter. EM waves exhibit 5 characteristics, namely: amplitude, wavelength, frequency, velocity, and period. Variations of these characteristics ensure that each wave is unique.  The majority of the different EM are non-ionizing, except UV, X-rays and gamma rays.

Background radiation

Background radiation can be found throughout the universe. It is present in space, food and water, and even in the air we inhale. According to the United Nations Scientific Committee, we have an annual intake of approximately 2.4 millisievert, due to different sources of background radiation. However, this value varies in different countries/regions. Radiation from space, also known as cosmic radiation, and UV rays from the sun are two types of dangerous ionizing radiation that threatens life on Earth. Fortunately, the ozone layer protects us from cosmic radiation and UV radiation to an extent. The ozone layer is currently depleting at a rapid rate and is allowing more intense UV rays to enter our atmosphere – therefore it is still necessary to apply sunblock/sunscreen when going to the beach.

Particulate radiation

It is released from particulate matter. For example, gamma rays are emitted from decaying radioisotopes found in nature. Atomic, and more specifically subatomic, particles that have high energies cause higher levels of radiation. Alpha and beta particles are the most well-known types of particle radiation.

Uses of radiation

There are numerous uses of radiation, with medicine, science, and technology being the principal applications of radiation. The field of medicine has seen many important advancements due to the introduction of radiation-utilizing technology. Ionizing radiation is chiefly used in medicine, for x-rays and radiotherapy.

The technology sector depends on forms of radiation to thrive. Current communications technology cannot exist without EM radiation.  Additionally, infrared and visible light are also used in many electronic devices. Lastly, scientists use radiation to improve other fields, such as medicine and technology, by continuing to conduct research on all types of radiation to discover solutions for current problems society faces.

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