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Topic: New Isotope of element 114  (Read 3313 times)

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Offline Dan1195

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New Isotope of element 114
« on: November 14, 2010, 09:30:57 AM »
This hasn't been posted here yet but LBNL has announced the creation of an atom of 285114 and its decay products (down to 265Rf which decays by SF). Paper is here: Phys. Rev. Lett. 105, 182701.

Couple observations. First, even with only one atom observed the chain agrees very well with adjacent nuclides, including the short(er) half-lifes of the adjacent N=167 nuclides 277Ds and 278Rg compared to other members of their respective decay chains.

Second enough aggregate data is present in this region to see that a change in structure occurs after N=170, which is also where the SF lifetime minima is in between the deformed N=162 and spherical N=184 shell enclosures. Prior to N=170 and above Z=100 virtually all odd Z nuclides except for Lr have alpha decay lifetimes close to that of adjacent nuclides with one less neutron due to hindrance factors. In example above 277Ds has a 5.7 ms half-life vs 4.2 ms for 278Rg. Beyond N=170 these hindrance factors for odd Z do not generally appear as large.

Third, 269Sg likely has significant SF branching as this occurs in both 267Sg and 271Sg.

As a footnote, these isotopes where originally claimed as part of the 293118 chain now widely believed to be faked. When this new chain is compared to those 3 purported chains and compared to the additional data we know have, it is clear that the 1999 chains simply look bogus or that something is just wrong with them. The data for Cn and 114 especially with the sub millsecond half-lifes claimed in 1999 just does not jibe with the alpha decay properties of adjacent isotopes which have now been reptoduced.

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