INFN: The Puzzle of the Origin of Elements in the Universe

[bystander]

The Puzzle of the Origin of Elements in the Universe
National Institute for Nuclear Physics (INFN) | Gran Sasso National Laboratory (LNGS) | 2015 Dec 17

A rare nuclear reaction that occurs in red giants has been observed for the first time at the Gran Sasso National Laboratory in Italy. This result was achieved by the LUNA experiment, the world's only accelerator facility running deep underground.

The LUNA experiment at the INFN Gran Sasso National Laboratory in Italy has observed a rare nuclear reaction that occurs in giant red stars, a type of star in which our sun will also evolve. This is the first direct observation of sodium production in these stars, one of the nuclear reactions that is fundamental for the formation of the elements that make up the universe. The study has been published in Physical Review Letters.

LUNA (Laboratory for Underground Nuclear Astrophysics) is a compact linear accelerator. It is the only one in the world installed in an underground facility, shielded against cosmic rays. The experiment aims to study the nuclear reactions that take place inside stars where, like in an intriguing and amazing cosmic kitchen, the elements that make up matter are formed and then driven out by gigantic explosions and scattered as cosmic dust. ...

Three New Low-Energy Resonances in the ²²Ne(p,γ)²³Na Reaction - LUNA Collaboration

• Physical Review Letters 115:252501 (15 Dec 2015) DOI: 10.1103/PhysRevLett.115.252501
  arXiv.org > nucl-ex > arXiv:1511.05329 > 17 Nov 2015

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Fusion - Energy Production in Stars

Carbon fusion generally requires temperatures in excess of 600-700 million Kelvins.

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Each line is a possible end-product of the fusion of two normal carbon nuclei (6 neutrons and 6 protons):

• The first, oxygen and helium products, are endothermic, meaning that it actually requires energy to occur (0.114 MeV).
  
  The second line creates neon and helium, and it releases 4.616 MeV of energy.
  
  The third possible outcome is sodium plus a proton, and it releases 2.238 MeV of energy.
  
  Fourth is magnesium-23 and a neutron, which is endothermic like the first reaction, requiring 2.605 MeV to occur.
  
  A fifth possible outcome is magnesium-24 plus a photon, and this releases the greatest amount of energy of the carbon fusion, 13.930 MeV.