« Back to Dictionary Index
A beta particle, also known as a β-particle, is an electron or positron emitted from the nucleus of a radioactive atom during the process of beta decay.
Characteristics of Beta Particles:
- Nature:
- Electron (β⁻): In β⁻ decay, a neutron in the nucleus of a radioactive atom decays into a proton, emitting an electron (β⁻) and an antineutrino
\(( \overline{\nu}_e )\) . - Positron (β⁺): In β⁺ decay, a proton in the nucleus decays into a neutron, emitting a positron (β⁺) and a neutrino
\(( \nu_e )\) .
- Charge and Mass:
- Electron (β⁻): It has a negative charge of -1 elementary charge (approximately -1.602 × 10^-19 coulombs) and a mass of about 9.109 × 10^-31 kilograms.
- Positron (β⁺): It has a positive charge of +1 elementary charge and the same mass as an electron.
- Emission and Energy:
- Beta particles are emitted with a range of energies, depending on the particular radioactive decay process.
- The kinetic energy of beta particles can vary significantly, from a few keV (kilo-electron volts) to several MeV (mega-electron volts), depending on the isotope and decay mode.
- Interaction:
- Beta particles interact with matter through ionization and excitation, losing energy as they penetrate material.
- They can travel different distances in matter depending on their energy level. Higher energy beta particles penetrate further than lower energy ones.
Applications:
- Radiation Detection: Beta particles are detected using specialized equipment such as Geiger-Müller counters and scintillation detectors.
- Medical Applications: In positron emission tomography (PET) scans, positron-emitting isotopes are used to image metabolic processes in the body.
- Nuclear Physics: Study of beta decay processes helps in understanding nuclear structure and interactions.
Summary:
Beta particles, whether electrons (β⁻) or positrons (β⁺), play a significant role in nuclear physics, radiation detection, and medical imaging. Their emission during beta decay provides valuable insights into the behavior of atomic nuclei and their interactions with matter.
« Back to Dictionary Index