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Terms and Definitions
Published in Rick Houghton, William Bennett, Emergency Characterization of Unknown Materials, 2020
Rick Houghton, William Bennett
Alpha particles consist of two protons and two neutrons and are about 7,000 times more massive than a beta particle. The increased mass means alpha particle radiation can be stopped by a sheet of paper or the dead layer of skin cells on a human. Comparatively, alpha particle radiation is not much of a hazard to the skin, but there are serious inhalation, ingestion, and injection hazards. Epithelial cells that line the respiratory and gastrointestinal tract have no dead layer of cells for protection. A radioisotope dust that is swallowed or inhaled will settle directly on live cells and cause local irradiation injury. The same type of injury can occur with eye contact. Because alpha particles are large and prone to collision while delivering energy over a short distance, they have potential to cause severe biological damage. Alpha radiation can only travel a few centimeters through air. Alpha particles are emitted from substances such as plutonium, radon, and radium.
Radioactivity in Drinking Water
Published in Joseph Cotruvo, Drinking Water Quality and Contaminants Guidebook, 2019
Alpha particles (α) are high-energy ionizing radiation emitted by some radioactive elements (e.g., radium-226). They are helium nuclei so they consist of two protons and two neutrons (= 4 atomic mass units), and are actually energetic helium ions (He+2). They are much heavier and larger than the other two principal types of radiation: beta (β) and gamma (γ).
Overview of Radiation Transport Physics and Space Environments
Published in John D. Cressler, H. Alan Mantooth, Extreme Environment Electronics, 2017
Alpha particles are produced by radioactive decays of nuclei. An alpha particle is simply a helium ion that was ejected from the nucleus. The energy is <10 MeV. The range in silicon is <100 μm. Traces of alpha emitters are found in semiconductor process and packing material. Purification of production materials and shielding can mitigate the alpha environment.
Monitoring and investigating the alpha emitter’s concentration in toothpaste and teeth, using CR-39 NTDs
Published in Radiation Effects and Defects in Solids, 2023
The natural radioactivity and environment are important since naturally occurring radionuclides are the major source of radiation exposure to humans. One of the main sources of public exposure to natural radioactivity is radium and radon, also its short-lived decay products (1). High concentrations of radon (222Rn) and its decay products are widely known to be dangerous to human health. The isotope Rn-222, produced from the decay of U-238, is the main source (approximately 55%) of internal radiation exposure to human life (2). It is commonly associated with different types of cancer, especially with lung cancer (2,3). Alpha particles are emitted when the radon decays. The alpha particles are suspected to include damage to the epithelial cell (3–5). Alpha particles are high Linear Energy Transfer (LET) radiation with a large amount of energy (3–7 MeV) (6). If alpha emission enters the body (upon being inhaled, ingested or injected) it becomes extremely dangerous. Because of this high mass and strong absorption, alpha particles are more damaging to living tissues because they are more massive and more highly charged than other types of ionizing radiation (7).
A Nuclear Decay Micropropulsion Technology Based on Spontaneous Alpha Decay
Published in Nuclear Science and Engineering, 2021
Shiyi He, Yan Xia, Fei Xu, Leidang Zhou, Xiaoping Ouyang
The nuclear process of alpha decay occurs when an excited nucleus spontaneously emits an alpha particle to reach a stable state.16 Alpha decay ejects high-energy alpha particles of 4 to 9 MeV spontaneously. A schematic diagram of the process is shown in Fig. 1. The nuclear reaction formula of alpha decay is shown as Eq. (1):