Alpha radiation is a type of ionizing radiation that is emitted during the process of radioactive decay. It produces alpha particles, which consist of two neutrons and two protons.
When the atoms within matter attempt to balance and need to get rid of excess atomic energy, this creates radioactivity. The unstable nuclei emits energy, and this spontaneous emission is what we know as radiation. The energy produced by matter will either be in the form of high-speed particles, or rays.
Radiation is either non-ionizing or ionizing. Non-ionizing radiation does not remove electrons from atoms or break molecular bonds, and it includes visible light, radar, and microwaves. Ionizing radiation, on the other hand, does have the ability to cause changes in the living cells of people, plants, and animals. It contains more energy and has the ability to displace or remove electrons. While ionizing radiation is beneficial and we use it to treat cancer and within smoke detectors, it can cause harm if it is not handled correctly.
There are five main types of ionizing radiation:
- Alpha particles
- Beta particles
- Gamma rays
Alpha particles may emit from naturally occurring materials, such as radium and uranium, or from elements which are man-made, such as americium and plutonium. Some important facts to understand about alpha radiation are:
- It is the least penetrating of all the types; it generally does not travel through more than a few inches of air. Its heaviness and short range is due to the fact that alpha radiation is actually an ejected helium nucleus
- A few inches of air, skin, and a sheet of paper are enough to block alpha radiation
- It cannot penetrate clothing
- Materials that emit alpha particles are only potentially dangerous if they are swallowed or inhaled; they do not pose a danger externally
- Instruments to measure alpha radiation have been developed, and special training is required to use these and conduct accurate measurements
The U.S. Nuclear Regulatory Commission (NRC) provides information, dose limits, and training requirements for workers who operate with and around nuclear materials and who may be exposed to radiation. For example, Title 10, Part 19 of the Code of Federal Regulations requires that individuals who are likely to receive a dose of 100 millirem or more in a year must receive training, as well as the appropriate personal protective equipment, to protect themselves. These individuals also have the right to know the exact amount of radiation they have been exposed to, and they have the right to ask the NRC for an inspection if they believe there are health and safety problems in their work environment. The annual total dose limit for radiation workers is 5,000 millirem (5 rem).