Beta particle

Alfa beta gamma radiation

Beta-minus Decay

Cs-137-decay

TrigaReactorCore

Beta radiation in a cloud chamber

Beta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive nuclei, such as potassium-40. The production of beta particles is termed beta decay. There are two forms of beta decay, beta-minus (β−) decay, and beta-plus (β+) decay, which produce electrons and positrons, respectively. Beta particles are a form of ionizing radiation and can be harmful to living tissue, leading to radiation damage, but they also have applications in medicine, nuclear physics, and radiocarbon dating.

Types of Beta Decay

Beta decay occurs in two forms:

• Beta-minus (β−) decay occurs when a neutron in the nucleus of an atom decays into a proton, an electron (the beta particle), and an antineutrino. The electron is ejected from the nucleus with high energy.
• Beta-plus (β+) decay, also known as positron emission, occurs when a proton in the nucleus is converted into a neutron, a positron (the beta particle), and a neutrino. The positron is the antimatter counterpart of the electron.

Interaction with Matter

Beta particles can penetrate living tissue to a certain extent, making them both a hazard and a tool. The penetration depth depends on the energy of the beta particles and the material they are passing through. In general, beta particles can be stopped by a few millimeters of aluminum or plastic. However, when beta particles are stopped, they can produce bremsstrahlung X-rays, which are a secondary radiation hazard.

Applications

Beta particles have several applications in various fields:

• In medicine, beta emitters are used in radiotherapy to treat certain types of cancer.
• In nuclear physics, beta decay studies help in understanding the weak force, one of the four fundamental forces in the universe.
• Radiocarbon dating relies on the beta decay of carbon-14 to estimate the age of organic materials.

Safety

Due to their ionizing nature, beta particles can pose health risks if not properly managed. Protective measures include using shielding materials, such as acrylic glass or aluminum, to stop beta particles and minimize the production of bremsstrahlung X-rays. Safety protocols also involve monitoring exposure and using personal protective equipment in environments where beta radiation is present.

See Also

• Alpha particle
• Gamma ray
• Radiation therapy
• Weak interaction