-
ed
0018933
againstthe Revalue for Eu)56 and a series of straight lines resulted with
slopes ranging from positive to negative values.
Pesitive slopes indica-
ted a simultaneous enrichment of the cloud particles in europium and the
product nuclide, whereas negative slopes showed that as the particles
became richer in europium they were more and more depleted in the
product nuclide,
Products having rare-gas and alkali metal precursors
had the steepest negative slopes while U, Np and Pb had small negative
slopes.
The more refractory oxide elements Nd, Be, Zr and Nb had
positive slopes and those elements such as Ca, which showed no fractionation with respect to europium, had infinite pesitive slopes,
The results.
are consistent with the view that these preducts having rare-gas or alkali
metal ancestors at the time of condensation will concentrate im the smaller
particles which have a larger surface-to-velume ratio,
Similar relationships have been found for several high yield air
bursts using Ba 140 as the secondary reference nuclide and Mo’ 99 as the
primary reference nuclide (the primary reference nuclide is the substance
used as reference in calculating the R-values; the secondary reference
nuclide is the substance used as abscissa in the R-value plots),
In this
reference system, Agi}, y237, call5, cs!36, Np*??, y?), and sr89
had approximately unit positive slepes while zr??, Cel 44, Pu“? and the
of 1.5,
age negative slopes
er
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ha
hs
rt
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ra
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e was
For these shots ther
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