Environmental Health & Safety

Radiation Glossary of Terms


As Low As Reasonably Achievable program applies to all radiation machines, except general license consumer products.


The decrease in the [radiation intensity] of any radioactive material with the passage of time due to the spontaneous emission of radiation from an atomic nucleus.

General license

A general license does not require filing an application with the State of California, but is subject to the same standards in terms of radiation protection as those individuals under a broadscope license.   Items which can be ordered under a general license include antistatic devices, calibration or reference sources, gauges, and depleted uranium. 

Ionizing Radiation

Examples include: ultra violet, x-ray, gamma ray, damages DNA, medical x-rays, and isotopes.


A device that emits light (electromagnetic radiation) through a process called stimulated emission.

Non Ionizing Radiation

Examples include: radio, micro waves, infrared, visible light, low frequency powerlines, optical-heat lamp, thermal heating, and non thermal-low current-static fields


Energy moving in the form of particles or waves. Familiar radiations are heat, light, radio waves, and microwaves. Ionizing radiation is a very high-energy form of electromagnetic radiation.


Radioactivity is the spontaneous emission of ionizing radiation from the nucleus of an unstable atom. Radioisotopes lose particles and energy through this process

Radioactive Materials

Material that contains unstable (radioactive) atoms that give off ionizing radiation as they decay.

Radiation Machine

Any device capable of producing radiation when the associated control devices are operated, but excluding machines and consumer products that have a . Examples of machines that produce ionizing radiation and non-ionizing radiation (high electric or magnetic fields) include: general license machines, irradiators, and x-rays. Other examples currently not used on campus are accelerators and neutron generators.

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Environmental Health & Safety

Environmental Health & Safety
Environmental Health & Safety

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