activity if the original contribution of tal
40
to this
parent-daughter complex is more than 11.5 percent of the
total activity of the combination.
The evidence in ‘the
records of samples whose analysis was begun early enough
for the build-up to show up,points toward their being very
little or no tar t© produced as an instantaneous fission
product.
This conclusion is borne out by studies of fis-
#
sicn product yields from p23 Made by Yaffe, et a1.2? and
Petruska et ait »
of Ba
140
who report yields of 6.32 + 0.24 percent
and 6.33 + 0.32 percent of Ce
140
,»respectively.
*
Since the difference is zero within experimental error,
140
, La
is not produced as an original fission product.
/
a2
3
The samples collected atground and ship stations may
be different due to fallout fractionation and possible
anisotropies in fission-product ejection from the weapons.°
That there is evidence that one or both of these mechanisms
are operating can be ascertained by comparison of the spectra of samples collected at different places for the same
shot.
No pattern is discernible however, with so few sample
collection locations.
Therefore it is not possible to say
anything more than that there seem to be discrepancies be“tween samples from the same shot which are too large to
explain in terms of measurement error alone, e.g., the 330
28
a:
‘