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Encyclopedia > Double beta decay
Nuclear processes
Radioactive decay processes

Nucleosynthesis Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles (radiation). ... Alpha decay is a form of radioactive decay in which an atomic nucleus ejects an alpha particle and transforms into a nucleus with mass number 4 less and atomic number 2 less. ... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... Cluster decay is the nuclear process in which a radioactive atom emits a cluster of neutrons and protons. ... Double electron capture is a decay mode for chemical elements that will occur when there are too many protons in the nucleus of an atom, and there isnt enough energy to undergo single electron capture. ... Electron capture is a decay mode for chemical elements that will occur when there are too many protons in the nucleus of an atom, and there isnt enough energy to emit a positron. ... This article is about electromagnetic radiation. ... Internal conversion or isomeric transition is the act of returning from an excited state by an atom or molecule. ... Neutron emission is a type of radioactive decay in which an atom contains excess neutrons and a neutron is simply ejected from the nucleus. ... Positron emission is a type of beta decay, sometimes referred to as beta plus (β+). In beta plus decay, a proton is converted to a neutron via the weak nuclear force and a beta plus particle (a positron) and a neutrino are emitted. ... Proton emission (also known as proton radioactivity) is a type of radioactive decay in which a proton is ejected from the nucleus. ... Spontaneous fission (SF) is a form of radioactive decay characteristic of very heavy isotopes, and is theoretically possible for any atomic nucleus whose mass is greater than or equal to 100 amu (elements near ruthenium). ... Nucleosynthesis is the process of creating new atomic nuclei either by nuclear fusion or nuclear fission. ...

  • Neutron Capture
    • The R-process
    • The S-process
  • Proton capture:
    • The P-process

In the process of beta decay unstable nuclei decay by converting a neutron in the nucleus to a proton and emitting an electron and anti-neutrino. In order for beta decay to be possible the final nucleus must have a larger binding energy than the original nucleus. For some nuclei, such as Germanium-76 the nuclei with atomic number one higher has a smaller binding energy, preventing beta decay from occurring. In the case of Germanium-76 the nuclei with atomic number two higher, Selenium-76 has a larger binding energy, so the "double beta decay" process is allowed. The R process (R for rapid) is a neutron capture process for radioactive elements which occurs in high neutron density, high temperature conditions. ... The S process (S for slow) is a neutron capture process in the decay of radioactive elements that occurs in lower neutron density, lower temperature conditions. ... The p process was believed to be a proton capture process which occurrs during supernovae explosions. ... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... Plural: nuclei In chemistry and physics, the nucleus (atomic nucleus) is the collection of protons and neutrons in the center of an atom that carries the bulk of the atoms mass and positive charge. ... Properties In physics, the neutron is a subatomic particle with no net electric charge and a mass of 939. ... Plural: nuclei In chemistry and physics, the nucleus (atomic nucleus) is the collection of protons and neutrons in the center of an atom that carries the bulk of the atoms mass and positive charge. ... Properties In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... Properties The electron is a subatomic particle. ... The neutrino is an elementary particle. ... Binding energy is the energy required to disassemble a whole into separate parts. ... General Name, Symbol, Number germanium, Ge, 32 Chemical series metalloids Group, Period, Block 14, 4, p Appearance grayish white Atomic mass 72. ... General Name, Symbol, Number selenium, Se, 34 Chemical series nonmetals Group, Period, Block 16, 4, p Appearance gray, metallic luster Atomic mass 78. ...


In double beta decay two neutrons in the nuclei are converted to protons, and two electrons and two anti-neutrinos are emitted. This process was first observed in 1986.


Neutrinoless double beta decay

The process described above is also known as two neutrino double beta decay, as two neutrinos are emitted. If the neutrino is a Majorana particle (this links to "spinor" wich is irrelevant to this subject, me thinks), meaning that the anti-neutrino and the neutrino are actually the same particle then it is possible for neutrinoless double beta decay to occur. In neutrinoless double beta decay the two neutrinos annihilate very quickly after they are produced, so the total kinetic energy of the two electrons would be exactly the difference in binding energy between the initial and final state nuclei. Several experiments have been proposed to search for neutrinoless double beta decay, as its discovery would indicate that neutrinos are indeed Majorana particles and allow a calculation of their mass. In mathematics and physics, in particular in the theory of the orthogonal groups, spinors are certain kinds of mathematical objects (group representations of Spin(N), roughly speaking) similar to vectors, but which change sign under a rotation of radians. ... Annihilation occurs when a particle collides with an antiparticle. ... Kinetic energy (also called vis viva, or living force) is energy possessed by a body by virtue of its motion. ...


See also


  Results from FactBites:
 
Double beta decay - Wikipedia, the free encyclopedia (411 words)
In the process of beta decay unstable nuclei decay by converting a neutron in the nucleus to a proton and emitting an electron and anti-neutrino.
In double beta decay two neutrons in the nuclei are converted to protons, and two electrons and two anti-neutrinos are emitted.
In neutrinoless double beta decay the emitted neutrino is immediately absorbed (as its anti-particle) by another nucleon of the nucleus, so the total kinetic energy of the two electrons would be exactly the difference in binding energy between the initial and final state nuclei.
Beta decay - Wikipedia, the free encyclopedia (777 words)
In nuclear physics, beta decay is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted.
In nature, most isotopes are beta stable, but a few exceptions exist with half-lives so long that they have not had enough time to decay since the moment of their nucleosynthesis.
Beta decay can be considered as a perturbation as described in quantum mechanics, and thus follows Fermi's Golden Rule.
  More results at FactBites »

 
 

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