TABLE 5.9 = Gamma Energy Measurements from Sample 4-¥39, Shot 4
Time
after Shot
}
Energy (Mev)
(days) 0.01 | 0.04 | 0.06] 0.09[0.14]0.2¢' | 0.29 [0.351043]0.50]0.8510.71
1.3
Observed Peak Height Relative to 0,09
|(1.57)(1.87)](4.0) {(2.0)]}-
3.4
0.24
-
0.35
9.2
-
-
0.72} 1.0 |=
|<
-
{10.581 1.0 j=
|0.30}
0.57 =
1.0 }|0.72 |
1.9 |0.60/0.41
8.1
-
4.1 !-
18.3
22.3
22.3
-
1.9
”
(0.15)) (0.13J-
0.591 1.0 |=
-
1.0
|=
9.15
{9.23}
|0.24]
|0.36}
-
-
-
-
-
-
[-
Mev Peak
-
je
[0.36|-
|0.10)-
jO0.12}|~
|=
0.26j{=
f-
J-
0.92
0.021
[27
-
[9.04 rd
|0.1910.19 ico
|0,06/0.07/-
10.0710.131fe
fe
le
[0.22 0.23 |=
5 eleded
Comparisons of Spectra of Samples frog Shote } through 4
0.01 Mev.
There was usually, but not always, one or more lower energy
In every curve studied the highest peak oecurred at 0.09 +
peaks near this energy. If the 0,09 Mev peak is given a relative height
of 1.0, then the relative heights of the other peaks were about 0.5 for
0.01 Mev and 0.7 for 0.04 Mev. These relative heights decreased with
time. There was another definite peak 0.20 Mev which ran about 0,30 of
the highest peak, Higher energy peaks were observed at 0.50 and 0.65
Mev ranging from 0.1 to 0.2 of the highest peak.
The 0.43 Mev peak how-
ever is doubtful since it appears in only one curve, The small NaI crystal
which was used was not satisfactory for higher energies. In addition,
the large amount of shielding required because of the high background at
the site increased the scattering which resulted in very high counts in
the low energy region and probably the peak at 0.50 Mev, The low efficienay
of the crystal at the higher energies, however, was the chief reason for
not taking spectra above the 1 Mev region.
0.09,
The energies and relative heights of the peaks at 0.04, 0.06,
0.20, and 0.29 Mev were very close to those observed in a pure
Np239 spectrum which would indicate larger amounts of Np*?? gammas.
of these peaks gradually disappeared as the Np decayed out.
Some
The following generalizations are evident from the analyses of
the gamma spectra:
1. There did not appear to be any significant difference in
the distribution of gamma-ray energies between the samples from the first
four detonations,
2. The gamma analyzer curves showed no important differences
between various samples from the same shot indicating that fractionation
was not detectable by this method.
3.
There was no great change in the relative heights of the
various gamma peaks with time, although there was a cetectable shift
from the high 0.10 Mev peak toward both the low (0.03 Mew) and high
(0.50 Mev)ends of the spectrum at later times,
gamna
4. There was a reletively large amount of 0.10 Mev
radiation present in the gross fallout mixture.
116