Alpha decay is a type of ionizing radiation in which alpha particles are ejected from the nuclei of unstable atoms. Alpha particles are large, powerful subatomic particles that are very destructive to human cells; however, they tend to lose their energy quickly, limiting their ability to penetrate materials. There are many ways in which science successfully uses alpha radiation in a beneficial way.
Alpha radiation is used to treat various forms of cancer. This process, called unsealed source radiotherapy, involves inserting tiny amounts of radium-226 into cancerous masses. The alpha particles destroy cancer cells but lack the penetrating ability to damage the surrounding healthy cells. Radium-226 has mostly been replaced by Safer, more effective radiation sources, such as cobalt-60. Xofigo, the brand name of Radium-223, is still used to treat bone cancer.
Alpha radiation from polonium-210 is used to eliminate static electricity in industrial applications. The positive charge of the alpha particles attracts free electrons, thus reducing the potential for local static electricity. This process is common in paper mills, for example.
Alpha radiation is used in some smoke detectors. The alpha particles from americium-241 bombard air molecules, knocking electrons free. These electrons are then used to create an electrical current. Smoke particles disrupt this current, triggering an alarm.
Radioisotope thermoelectric generators are used to power a wide array of satellites and spacecraft, including Pioneer 10 and 11 and Voyager 1 and 2. These devices function like a battery, with the benefit of a long life span. Plutonium-238 serves as the fuel source, producing alpha radiation resulting in heat, which is converted to electricity.
Alpha radiation is used as an energy source to power heart pacemakers. Plutonium-238 is used as the fuel source for such batteries; with a half-life of 88 years, this source of power provides a long lifespan for pacemakers. However, due to their toxicity, difficulties with patients in traveling, and problems with disposal, they are no longer used.
Remote Sensing Stations
The Unites States Air Force uses alpha radiation to power remote sensing stations in Alaska. Strontium-90 is typically used as the fuel source. These alpha-powered systems enable unmanned operations for long periods of time without the need for servicing. Local opposition to the use of radiation is prompting the air force to replace many of these devices with alternative power sources, such as diesel-solar hybrid generators.
Alpha radiation is used to provide heating for spacecraft. Unlike radioisotope thermoelectric generators that convert heat to electricity, radioisotope thermal generators make direct use of the heat generated by alpha decay.
Coast Guard Buoys
The U.S. Coast Guard uses alpha radiation to power some of their oceanic buoys. Like in many of the other applications, the alpha radiation provides a power source with a long lifespan. Strontium-90 is the typical power source for these buoys.
Oil Well Equipment
The oil industry uses alpha radiation to power some of their offshore equipment. This provides a long-lasting power source for remotely located devices that have limited access to crews. Strontium-90 is the typical fuel source for such batteries.
Seismic and Oceanographic Devices
Alpha radiation is also used to power a wide array of seismic and other oceanographic devices. These unmanned devices are often located in isolated locations, such as on the ocean floor, which limits the practicality of short-term batteries. Strontium-90 is the most common material used in these alpha decay batteries.
- US Environmental Protection Agency: Radiation Basics
- Peninsula Clarion
- American Institute of Aeornautics and Astronautics, Inc.; Space Nuclear Power: Opening the Final Frontier; Gary L. Bennett
- US Congress, Office of Technology Assessment; Power Sources for Remote Arctic Applications; June 1994
- Indian Pacing Electrophysiol Journal; Trends in Cardiac Pacemaker Batteries; Venkateswara Sarma Mallela, et al.; 2004
- Oak Ridge Associated Universities: Plutonium Powered Pacemaker