Basic Radiological Science
Thomas A. Carder in Handling of Radiation Accident Patients, 1993
As a nucleus strives to become stable, a neutron may decay (transform) and eject the electron component of the decaying neutron from the nucleus. The ejected electron is now a particle of beta radiation (P). Beta radiation is an example of particulate radiation (a particle of matter as opposed to a bundle of energy). The beta particle is therefore a high-speed free electron. The main difference between a beta particle and a free electron is the origin of the particle. The beta particle comes from the nucleus of a radioactive atom. The free electron comes from the electron shells as in the case of the disassociated electron resulting from ionization described in Section 2 and Figure 1.5. A beta particle and an electron are so similar that a beta particle may be captured as an electron by an atom that needs another electron. However, the beta particle has more more kinetic energy (energy of motion) than the electron since the beta particle is a projectile from a nucleus of radioactive material. Ejection of a beta particle from the neutron decay (neutron transformation) accounts for the electron component of the neutron.
External Beam Radiotherapy and Brachytherapy
Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple in Basic Urological Sciences, 2021
The radioactive decay of an atomic nucleus results in:Alpha radiation: emission of alpha particles (two protons, two neutrons).Beta radiation: emission of beta particles.beta− = electronsbeta+ = protonsGamma radiation: emission of electromagnetic energy (photon).
Intravascular Radiation Detectors to Detect Vulnerable Atheroma in the Coronary Arteries
Robert J. Gropler, David K. Glover, Albert J. Sinusas, Heinrich Taegtmeyer in Cardiovascular Molecular Imaging, 2007
The beta particles sensed by the detector can be positively or negatively charged. Positively charged particles, positrons, are emitted as part of positron emitting radionuclide decay (nuclides such as fluorine-18) while negatively charged particles are emitted in the course of conventional (negatron) beta decay (iodine-131, or phosphorus-32). The mean path length of both positron and negatron particles depends on the energy of emitted radiation, and is typically less than 3 mm in water. This physical phenomena permits localization of beta radiation based solely on proximity of the source to the detector. For example, 18Fluorine (97% incidence of mean energy 0.25 MeV beta +) has an average range in water of 0.64 mm (very similar to the beta particle from 131Iodine), while 82Rubidium (83% incidence of mean energy 1.5 MeV beta +) still has an average range of only 4.29 mm.a
Decontamination of rat and human skin experimentally contaminated with 99mTc, 201Tl and 131I radionuclides using “Dermadecon” – a skin decontamination kit: an efficacy study
Published in Cutaneous and Ocular Toxicology, 2018
Dhruv Kumar Nishad, Supriya Bhalla, Kushagra Khanna, Braj Gaurav Sharma, Harish Singh Rawat, Gaurav Mittal, Aseem Bhatnagar
Radioactive material releases alpha, beta and gamma radiations. Alpha particles, consisting of protons (2) and neutrons (2), are an ionizing type of radiation with low capacity to penetrate living tissue (less than 0.1 mm)3. Beta particles are electrons or positrons that are less ionizing, but have more penetrating power (up to a few millimeters). Beta radiation travels only a short distance in tissue, depending on its energy and could be a substantial source of dose to skin. Gamma rays are sparsely ionizing electromagnetic radiation that penetrates the living tissue, typically generating fast electrons that deposit energy resulting in tissue damage. The health hazards resulting from radionuclides that emit these types of particles largely occur after internal deposition4 exposures to gamma radiation will affect skin as a result of external contamination and possible secondary internal (systemic) uptake of radionuclide. The acceptable levels of radionuclide particle contamination should be averaged over 10−2 m2 in the case of skin generally, or over 3 × 10−2 m−2 in the case of hands5. The stratum corneum functions as a reservoir for radionuclide and as a medium for percutaneous absorption. The rapidly growing germinativum layer of epidermal cells is predominantly susceptible to engrossed energy of beta and gamma emissions6.
The potential of PSMA-targeted alpha therapy in the management of prostate cancer
Published in Expert Review of Anticancer Therapy, 2020
Luca Filippi, Agostino Chiaravalloti, Orazio Schillaci, Oreste Bagni
The alpha emission consists of a positively charged particle, identical to the naked helium-4 (4He) nucleus, formed by two protons and two neutrons bound together, having an extremely greater mass as compared to that of beta particles. Alpha particle is monoenergetic, with emission ranging between 5 and 9 MeV and presents a linear track of 50–100 micron, which entails an almost exclusive radiation delivery to the target and the strictly neighboring cells [12]. Alpha particles are classified as high linear energy transfer (LET) radiation and represent effective ionizing agents. The main advantage of utilizing alpha radiations consists in their capability of inducing effects independently from the oxygenation status of the cell. It is well known that hypoxic tumors are three-fold less sensitive to radiations than well-oxygenated tissues, since low LET radiations mainly produce deoxyribonucleic acid (DNA) damages through water hydrolysis and free radical formation. On the contrary, this ‘oxygen effect’ is of minor relevance for high LET radiations, such as alpha particles.
Investigation of Radon Sources, Health Hazard and Risks assessment for children using analytical and geospatial techniques in District Bannu (Pakistan)
Published in International Journal of Radiation Biology, 2022
Huma Shakoor, Noor Jehan, Sardar Khan, Nimat Ullah Khattak
For the determination of Rn concentration in drinking water of district Bannu RAD-7 radon detection equipment was used. The apparatus RAD-H2O was developed by the manufacturer specifically to perform the detection and measurement of Rn gas in water (Avery et al. 2018). This apparatus presents a result after a 30 min analysis. After every sample analysis the apparatus is purged to remove the impurities and reduce the internal humidity of RAD-7 detector. The Rn content in water sample during the process of analysis 222Rn nucleus that decay with in the cell and converted into a decay product positively charged ion 218Po. The half-life of 218Po is 3.1 min and emits alpha radiation which decays upon the detector’s active surface, the alpha particles have a probability of 50% to enter the detector and produces an electrical signal proportional in strength, to the energy of the alpha particles (Faheem and Rahman 2008). The same alpha nucleus decays and produces beta particles, which are not detected in the detection cell. Different isotopes of Rn have different alpha energies, and produce different strength signals in the detector. The RAD-7 detectors RAD-H2O amplifies filters and sorts the signals according to their strength and uses only 218Po signals for the detection of Rn concentration in drinking water (Durridge 2015).
Related Knowledge Centers
- Alpha Particle
- Beta Decay
- Gamma Ray
- Ionizing Radiation
- Radioactive Decay
- Atomic Nucleus
- Radiation Protection
- Nuclear Fission Product
- Caesium-137
- Phosphorus-32