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??-Radioactivity of cerium-142

Nature

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, ,
DOI: 10.1038/184630a0

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Abstract

JOHNSON AND NIER1 have measured the atomic masses of some of the rare-earth isotopes and have shown that the mass difference cerium-142-(barium-138 + helium-4) is equivalent to 1.68 ?? 0.10 MeV. Similar results for the naturally occurring samarium and neodymium isotopes show that the ??-active isotope of each element is the one having the largest possible decay energy. Rasmussen and others2 suggest that the two or three neutrons just beyond the closed shell of 82 neutrons have decreased binding energies and hence the ??-energy has a maximum about 84 neutrons. Johnson and Nier suggest that the ??-decay of cerium-142 may take place with enough energy to be experimentally observable. Porschen and Riezler3 examined a sample of un-enriched cerium ammonium citrate using nuclear track plates sensitive to ??-particles. No ??-activity was observed after a 30-day exposure of 1.2 mgm. of the cerium salt. In 1957 Riezler and Kauw4 reported an alpha activity for an enriched sample of cerium-142. From their results they calculated a half-life of 5.1 ?? 1015 years with an uncertainty factor of 2. ?? 1959 Nature Publishing Group.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
??-Radioactivity of cerium-142
Series title:
Nature
DOI:
10.1038/184630a0
Volume
184
Issue:
4686
Year Published:
1959
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Nature
First page:
630