spectra from samples collected at different places and different shots
with time,
A comparative analysis for only one fallout sample from each
shot is presented here.
5el3el
Shot
A sample of fallout from Rongelap was analysed on + 29 and
+ 31 days after detonation, The results are shown in Table 5.6. Most
of the same peaks show up for both curves with the exception of 0.03 and
0.27 Mev which do not appear at 31 days.
Also the relative height of
the 0.22 Mev curve is somewhat lower at 31 days. The 31 day curve shows
a greater similarity to the other shots than the 29 day curve. In view
of the fact that the calibration of the analyser was not completed at
the time the first analysis was made the data collected on + 31 days are
probably the more significant of the two analyses.
TABLE 5.6 - Gamma ergy Measurements from Rongelap Sample, Shot 1
Tine
after Shot
(days)
[0.03
29
0.57
0.07
0.10
Energy(Yev)
0.15 0.22
0.27
0.32
0.50 10.62
Observed Peak Height Relative to 0.10 Mev Peak
31
5elede2
-~
0.80
1,0
0.86
0.59
0.57
1,0
0.57
0.12
0.35
-
”-
0.17
0.18
|0.05
0.12
0.15
0.05
Shot 2
On + 2 days there are significant peaks at 0.03, 0.08, 0.23,
0.30, 0.38, 0.62.
On + 3 days, the 0.30 haa dropped way down, the 0.23 is about
the same, the 0.08 is considerably higher and a very high peak has shown
up at 0.12 Mev along with a smiler 0.15 peak. The higher energies, 0.38
and 0,62 have decreased considerably.
On + 4 days the high peak is still 0.12 Mev, the 0.08 and 0.15
are somewhat lower, and the 0.23 is about the same. There is a 0.28 peak
slightly lower than the 0.23.
The higher energies are still very low.
On + 6 days the 0.03 peak is the same as it was in all pre-
vious plots. There is very little change from R + 4 days.
On + 6.25 days. Very similar to R + 6 days. The 0.06 and
0.15 peaka are now symmetrical bulges on either side of the high 0.12
peak.
appear.
;
On + 9 days. Same ac R + 6 except the 0.03 peak does not
On + 11 days. Similar to R + 9 days except 0.03 peak again
appears, ‘There is a low but definite peak at around 0.50 which has bees
present since + 4 days,