+1 credit
| Version | Summary | Created by | Modification | Content Size | Created at | Operation |
|---|---|---|---|---|---|---|
| 1 | Vivi Li | -- | 1555 | 2022-10-21 01:45:50 |
Video Upload Options
The proton–proton chain reaction is one of two known sets of nuclear fusion reactions by which stars convert hydrogen to helium. It dominates in stars with masses less than or equal to that of the Sun, whereas the CNO cycle, the other known reaction, is suggested by theoretical models to dominate in stars with masses greater than about 1.3 times that of the Sun. In general, proton–proton fusion can occur only if the kinetic energy (i.e. temperature) of the protons is high enough to overcome their mutual electrostatic repulsion. In the Sun, deuterium-producing events are rare. Diprotons are the much more common result of proton–proton reactions within the star, and diprotons almost immediately decay back into two protons. Since the conversion of hydrogen to helium is slow, the complete conversion of the hydrogen in the core of the Sun is calculated to take more than ten billion years. Although called the "proton–proton chain reaction", it is not a chain reaction in the normal sense. In most nuclear reactions, a chain reaction designates a reaction that produces a product, such as neutrons given off during fission, that quickly induces another such reaction. The proton-proton chain is, like a decay chain, a series of reactions. The product of one reaction is the starting material of the next reaction. There are two such chains leading from Hydrogen to Helium in the Sun. One chain has five reactions, the other chain has six.
References
- Hans Bethe (Mar 1, 1939). "Energy Production in Stars". Physical Review 55: 434-456. doi:10.1103/PhysRev.55.434. https://journals.aps.org/pr/pdf/10.1103/PhysRev.55.434.
- Iliadis, Christian. (2007). Nuclear physics of stars. Weinheim: Wiley-VCH. ISBN 9783527406029. OCLC 85897502. http://www.worldcat.org/oclc/85897502
- Phillips, A. C. (Anthony C.), –2002. (1999). The physics of stars (2nd ed.). Chichester: John Wiley. ISBN 0471987972. OCLC 40948449. http://www.worldcat.org/oclc/40948449
- This time and the two other times above come from: Byrne, J. Neutrons, Nuclei, and Matter, Dover Publications, Mineola, NY, 2011, ISBN:0486482383, p 8.
- Adelberger, Eric G. (12 April 2011). "Solar fusion cross sections. II. The pp chain and CNO cycles". Reviews of Modern Physics 83 (1): 201. doi:10.1103/RevModPhys.83.195. Bibcode: 2011RvMP...83..195A. https://dx.doi.org/10.1103%2FRevModPhys.83.195
- LeBlanc, Francis. An Introduction to Stellar Astrophysics.
- Burbidge, E.; Burbidge, G.; Fowler, William; Hoyle, F. (1 October 1957). "Synthesis of the Elements in Stars". Reviews of Modern Physics 29 (4): 547–650. doi:10.1103/RevModPhys.29.547. Bibcode: 1957RvMP...29..547B. This value excludes the 2% neutrino energy loss. https://dx.doi.org/10.1103%2FRevModPhys.29.547
- Claus E. Rolfs and William S. Rodney, Cauldrons in the Cosmos, The University of Chicago Press, 1988, p. 354.
- Bellini, G. (2 February 2012). "First Evidence of pep Solar Neutrinos by Direct Detection in Borexino". Physical Review Letters 108 (5): 051302. doi:10.1103/PhysRevLett.108.051302. PMID 22400925. Bibcode: 2012PhRvL.108e1302B. https://dx.doi.org/10.1103%2FPhysRevLett.108.051302
- Int'l Conference on Neutrino and Dark Matter, Thursday 07 Sept 2006, https://indico.lal.in2p3.fr/getFile.py/access?contribId=s16t1&sessionId=s16&resId=1&materialId=0&confId=a05162 Session 14.
