Journal of Fusion Energy

, Volume 25, Issue 3–4, pp 141–144

Observational Confirmation of the Sun’s CNO Cycle


DOI: 10.1007/s10894-006-9003-z

Cite this article as:
Mozina, M., Ratcliffe, H. & Manuel, O. J Fusion Energ (2006) 25: 141. doi:10.1007/s10894-006-9003-z


Measurements on \(\gamma\)-rays from a solar flare in Active Region 10039 on 23 July 2002 with the RHESSI spacecraft spectrometer indicate that the CNO cycle occurs at the solar surface, in electrical discharges along closed magnetic loops. At the two feet of the loop, H+ ions are accelerated to energy levels that surpass Coulomb barriers for the \(^{12}\hbox{C}(^{1}\hbox{H}, \gamma)^{13}\hbox{N}\hbox{ and }^{14}\hbox{N}(^{1}\hbox{H}, \gamma)^{15}\hbox{O}\) reactions. First X-rays appear along the discharge path. Next annihilation of \(\beta^{+}\)-particles from 13N and 15O (t1/2=10 m and 2 m) produce bright spots of 0.511 MeV \(\gamma\)’s at the loop feet. As 13C increases from \(\beta^{+}\)-decay of 13N, the \(^{13}\hbox{C}(\alpha, \hbox{n})^{16}\hbox{O}\) reaction produces neutrons and then the 2.2 MeV emission line appears from n-capture on 1H. These results suggest that the CNO cycle changed the 15N/14N ratio in the solar wind and at the solar surface over geologic time, and this ratio may contain an important historical record of climate changes related to sunspot activity.


CNO cycle H-fusion solar flare electrical activity \(\gamma\)-rays climate N-15 C-13. 

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  1. 1.Emerging TechnologiesMt. ShastaUSA
  2. 2.Astronomical Society of South AfricaKloofSouth Africa
  3. 3.Nuclear ChemistryUniversity of MissouriRollaUSA

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