FO
UM
IN
MIXED
SION PRODUCTS
In a given sample containing the fission praducts of Pu or 0798 it
.
on
is necessary to have a theoretical messure of the (Sr®® « Sr®°)/
(total fission activity) ratic as a functicn of time.
WT
Hurter and Ballou have derived aunroximate excressions for total
Ung ot
7 5a
OY.
fission product activity as a functicn of time.
in minutes, these equations are:
tad
cee og,
If it is expressed
A(t) = (156000)¢73:78
l day ¢t <b days
“aT
A(t) = (2800 )t74°9
4 days< t < 100 days
zea
A(t) = (2-16x10%)t7*°®9
“TP rt
123°
At 130 days after burst time, Sr®* and Sr®° contribute 10% and 0.35
we
| 2
100 days ¢ t < 3 years
respectively to fission product.activity.
The ratio of
for
J
any time is then calculated from the Sr half lives and the A(t)
formulae. This ratio has been plotted in Fig. A-l.
yes
With a knowledge of the percent contribution of each Sr isotope to
re
78
i
total activity, the disintezration rates of Sr®® and Sr°° at a
time are readily obtained using the A(t) data. The ratio of Sr
Sr®* has been plotted fram 1-1000 days in this manner in Pig. vn.
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ae
z
4g
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UNCL, SSIZILu
00131986.04
103 107b