LONG-RANGE FALLOUT FROM SEDAN AND SMALL BOY
9¢
Table 1— DISINTEGRATIONS PER MINUTE RATIOS TO *®Mo AT SHOT TIME FOR
SEDAN AIR-FILTER SAMPLES ADJUSTED FOR BACKGROUND
Source and
sample No.
s9gr
Kaycee, 107
Midwest, 167
Casper ATT,
142
Casper ATT,
157
Casper, 117
Orin, 112
Pepperville,
173
Average
Katcoff,
thermal 2*U
Dolan, 14-Mev
238yy
2.54
90S;
Fr
iy
103A)
106 By
liTCg
(1073
(1072),
(07)
(1074)
(1073s
(1079
Ba
lice
144
(1077)
(16
14.0
4.58
2.39
1.92
11.0
0
2.24
4.31
7.25
0
2.16
56.50
2.99
7.00
0
2.10
2.28
4.05
3.97
3.98
0
0
3.39
3.60
2.19
9.59
6.06
8.93
0
0
0
3.12
2.60
2.30
2.77
2.81
2.38
4.7
2.92
6.74
5.26
4.66
4.92
4.06
3.45
2.15
0
0
0
0
15
0
4.32
8.49
2.60
2.57
2.81
0.67
6.06
3.94
0
0
3.04
7.38
2.34
3.01
5.31
4.56
3.13
~0
~0
0.0434
0.258
4.4
~0.43
0.34
0.047
0.0257
0.227
~8.3
~0.
0.0248
0.144
3.49
0.545
0.356
0.0268
0.170
0
~0
1.52
0.287
2.60
4.08
2.48
0
6.27
1.
0.
adjusted for the preshot background levels. The theoretical ratios fox
the thermal fission of **U by Katcoff? and the 14-Mev neutron fissior
of 7817 by Dolan’ are listed in Table 1 for reference. Presumably the
production ratios for the Sedan shot would be closer to Dolan’s figures.
There are no obvious trends in the data with collection site which
suggests that the two levels in the cloud were not fractionated with
respect to each other. The zeros in Table 1 represent the situation
where no measurable activity was found or where the measured activity was less than the background activity. Comparing the average
ratios with Dolan’s values shows a deficiency of zr, ‘'Ce, and “*Ce
with respect to **Mo in the airborne particulate matter of the Sedan
debris. The radionuclides **sr, “sr, *'y, '*"Cs, and “°Ba have rare
gaseous or volatile precursors. Because of their volatile precursors,
all of these nuclides show a surplus to **Mo compared to Dolan’s
production values. Ruthenium has volatile oxides, and both 'Ru and
06Ru reflect an overabundance with respect to **Mo. However, it is
likely
that the 103 and 106 mass chains would be present as their
respective niobium or molybdenum precursors during the time of
radioactive-particle formation.
The disintegrations per minute ratios to **Mo at shot time adjusted
for background levels are given in Table 2 for the fallout-collector
samples. As for the air-filter samples, there is no observable trend
with collection site. The Zr behaves as a refractory exhibiting a
deficiency in the fallout, whereas the **Sr, sr, *y, !Ru, Ru, '’cs,
and ‘°Ba show a surplus.
Contrary to the air-filter samples, '!Ce
and ‘Ce also show a surplus with respect to Mo although there are
several zeros for these nuclides in Table 2, These zeros may be the