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 Automatic translation  Automatic translation Category: light and photons
Updated July 19, 2021
  Layers of the Sun

Image: The different layers of the Sun, the nucleus, the radiative zone, the convection zone, the photosphere, the chromosphere and finally the solar corona.
At the heart the fusion of a gram of hydrogen releases as much energy as 300 tons of oil.

  Probability of particle fusion

Image: The size or position of a proton is a probability density represented by a curve. The further away from the top of the curve, the less the presence of the proton or the size of the proton is likely. However, at the bottom of the curve, the probability of having 2 protons merging is low but not zero.
For the nuclear reaction « to ignite », it is necessary that protons (hydrogen nuclei) come into contact. Then one of the two protons turns into a neutron. Without radioactivity, this transformation would be impossible. Two protons, even in contact, are unable to cross the Coulomb barrier, they push back. But the proton can transiently transform into a neutron by emitting a particle (W boson). This W boson is immediately reabsorbed, the neutron becoming proton again. Very rarely, it happens that the W boson decays into a positron and a neutrino and at this point, the neutron remains a neutron. It can then merge with the other proton to form a nucleus of deuterium and switch on the « proton-proton chain ».


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