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UCRL-6252
It is interesting to note that the csi data from both v3? and ye38 fission
also appear to follow a linear behavior, although the fit is not quite as good
as for the other nuclides.
This linear behavior suggests that the charge dis-
tributions of the two modes also remain relatively unchanged with increasing
excitation energy.
Comparison of the rapid rise of the cs'36 R values with
the relatively constant cl?! R values further suggests that the charge distributions for each of the two basic modes differ quite markedly.
As was pointed out previously, if the data from thermal neutron fission
were to be consistent with the two-mode interpretation of the fast neutron fission data, then the lines for the fast neutron fission of U
through the point (1,1).
235
should all pass
Using the parameters of the lines obtained above we
can calculate the R values for the various other species when the R value for
i
Cd ts is equalto 1.
-
oo,
2
Table V lists these calculated values for neutron-induced
.
eas
:
.
fission in U 35 . With the exception of csiF6 the deviation of the various lines
from the point (1, 1) is far greater than could be reasonably expected from
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statistical considerations alone.
It is quite probable that the fission process is much more complex than
the picture set forth in Sec. II.
The discrepancy between the thermal neutron
data and the fast neutron data in y235 fission would seem to bear this out.
It.does not seem likely that this discrepancy is entirely explained by the
fact that thermal neutron fission represents fission from a single nuclide where-
as the fast neutron fission yield data represents fission from more than one
nuclide.
If contributions from a second species undergoing fission were such
as to cause the lines to deviate from the thermalneutron point, they would also be most likely to cause a noticeable curvature in the lines.
However, over
certain ranges of excitation energies, the two-mode fission hypothesis may
| Serve as a very good approximation, and this manner of plotting fission yield
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