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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:

  1. 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 \(( \nu_e )\).
  1. 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.
  1. 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.
  1. 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.

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