World Library  
Flag as Inappropriate
Email this Article

Calcium-48

Article Id: WHEBN0003611130
Reproduction Date:

Title: Calcium-48  
Author: World Heritage Encyclopedia
Language: English
Subject: Ununoctium, Isotopes of copernicium, Island of inversion, Neutrino Ettore Majorana Observatory, Isotopes of calcium
Collection: Isotopes of Calcium
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Calcium-48

Calcium-48
General
Name, symbol Calcium-48,48Ca
Neutrons 28
Protons 20
Nuclide data
Natural abundance 0.187%
Half-life (4.3+3.8
−2.5
) × 1019 a
Isotope mass 47.952534(4) u

Calcium-48 is a scarce isotope of calcium containing 20 protons and 28 neutrons. It makes up 0.187% of natural calcium by mole fraction.[1] Although it is unusually neutron-rich for such a light nucleus, the only radioactive decay pathway open to it is the extremely rare process of double beta decay. Its half-life is about 4.3×1019 years,[2] so for all practical purposes it can be treated as stable. One factor contributing to this unusual stability is that 20 and 28 are both magic numbers, making 48Ca a "doubly magic" nucleus.

Since 48Ca is both stable and neutron-rich, it is a valuable starting material for the production of new nuclei in particle accelerators, both by fragmentation[3] and by fusion reactions with other nuclei, for example in the recent production of ununoctium.[4] Heavier nuclei generally require a greater fraction of neutrons for maximum stability, so neutron-rich starting materials are necessary.

48Ca is the lightest nucleus known to undergo double beta decay and the only one simple enough to be analyzed with the sd nuclear shell model. It also releases more energy (4.27 MeV) than any other double beta decay candidate.[2] These properties make it an interesting probe of nuclear structure models and a promising candidate in the ongoing search for neutrinoless double beta decay.

See also

References

  1. ^ Coursey, J. S.; D. J. Schwab; R. A. Dragoset (February 2005). "Atomic Weights and Isotopic Compositions". NIST Physical Reference Data. Retrieved 2006-10-27. 
  2. ^ a b Balysh, A.; et al. (1996). "Double Beta Decay of 48Ca". Physical Review Letters 77 (26): 5186–5189.  
  3. ^ Notani, M.; et al. (2002). "New neutron-rich isotopes, 34Ne, 37Na and 43Si, produced by fragmentation of a 64A MeV 48Ca beam". Physics Letters B 542: 49–54.  
  4. ^ Oganessian, Yu. Ts.; et al. (October 2006). "Synthesis of the isotopes of elements 118 and 116 in the 249Cf and 245Cm+48Ca fusion reactions". Physical Review C 74 (4): 044602.  
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.