Radioactivity an Introduction
Radioactivity refers to the particles which are emitted from nuclei
as a result of nuclear instability. Because the nucleus experiences the
intense conflict between the two strongest forces( Binding force and Electrostatic force)*
in nature, it should not be surprising that there are many nuclear isotopes
which are unstable and emit some kind of radiation. The most common types of
radiation are called alpha, beta, and gamma radiation, but there are several
other varieties of radioactive decay.
Radioactive decay rates are normally stated in terms of their half-lives, and the half-life of a given nuclear species is related to its radiation risk. The different types of radioactivity lead to different decay paths which transmute the nuclei into other chemical elements. Examining the amounts of the decay products makes possible radioactive dating.
Radiation from nuclear sources is distributed equally in all directions, obeying the inverse square law.
PS : Instability is here referred to the Neutron to Proton Ratio.
* The two forces due to more number of protons means more Repulsion, more neutrons means more Binding Energy(Bind is to hold the nucleons Together) This gives birth to Instability.
** nucleons are the particles inside nucleus.
ALPHA DECAY
Composed of two protons and two neutrons, the alpha particle is a nucleus of the element helium. Because of its very large mass (more than 7000 times the mass of the beta particle) and its charge, it has a very short range. It is not suitable for radiation therapy since its range is less than a tenth of a millimeter inside the body. Its main radiation hazard comes when it is ingested into the body; it has great destructive power within its short range. In contact with fast-growing membranes and living cells, it is positioned for maximum damage.
BETA DECAY
Beta particles are just electrons from the nucleus, the term "beta particle" being an historical term used in the early description of radioactivity. The high energy electrons have greater range of penetration than alpha particles, but still much less than gamma rays. The radiation hazard from betas is greatest if they are ingested.
Beta emission is accompanied by the emission of an electron anti neutrino which shares the momentum and energy of the decay.
The emission of the electron's antiparticle, the positron, is also called beta decay. Beta decay can be seen as the decay of one of the neutrons to a proton via the weak interaction. The use of a weak interaction Feynman diagram can clarify the process.
GAMMA DECAY
Gamma radioactivity is composed of electromagnetic rays. It is distinguished from x-rays only by the fact that it comes from the nucleus. Most gamma rays are somewhat higher in energy than x-rays and therefore are very penetrating.
PENETRATION OF PARTICLES IN MATTER
Though the most massive and most energetic of radioactive emissions, the alpha particle is the shortest in range because of its strong interaction with matter. The electromagnetic gamma ray is extremely penetrating, even penetrating considerable thicknesses of concrete. The electron of beta radioactivity strongly interacts with matter and has a short range.
Radioactive decay rates are normally stated in terms of their half-lives, and the half-life of a given nuclear species is related to its radiation risk. The different types of radioactivity lead to different decay paths which transmute the nuclei into other chemical elements. Examining the amounts of the decay products makes possible radioactive dating.
Radiation from nuclear sources is distributed equally in all directions, obeying the inverse square law.
PS : Instability is here referred to the Neutron to Proton Ratio.
* The two forces due to more number of protons means more Repulsion, more neutrons means more Binding Energy(Bind is to hold the nucleons Together) This gives birth to Instability.
** nucleons are the particles inside nucleus.
ALPHA DECAY
Composed of two protons and two neutrons, the alpha particle is a nucleus of the element helium. Because of its very large mass (more than 7000 times the mass of the beta particle) and its charge, it has a very short range. It is not suitable for radiation therapy since its range is less than a tenth of a millimeter inside the body. Its main radiation hazard comes when it is ingested into the body; it has great destructive power within its short range. In contact with fast-growing membranes and living cells, it is positioned for maximum damage.
BETA DECAY
Beta particles are just electrons from the nucleus, the term "beta particle" being an historical term used in the early description of radioactivity. The high energy electrons have greater range of penetration than alpha particles, but still much less than gamma rays. The radiation hazard from betas is greatest if they are ingested.
Beta emission is accompanied by the emission of an electron anti neutrino which shares the momentum and energy of the decay.
The emission of the electron's antiparticle, the positron, is also called beta decay. Beta decay can be seen as the decay of one of the neutrons to a proton via the weak interaction. The use of a weak interaction Feynman diagram can clarify the process.
GAMMA DECAY
Gamma radioactivity is composed of electromagnetic rays. It is distinguished from x-rays only by the fact that it comes from the nucleus. Most gamma rays are somewhat higher in energy than x-rays and therefore are very penetrating.
PENETRATION OF PARTICLES IN MATTER
Though the most massive and most energetic of radioactive emissions, the alpha particle is the shortest in range because of its strong interaction with matter. The electromagnetic gamma ray is extremely penetrating, even penetrating considerable thicknesses of concrete. The electron of beta radioactivity strongly interacts with matter and has a short range.
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