CHAPTER X
NUCLEAR CLOUD SAMPLING
In the early days of sampling little was known about content of the
cloud, the relationship between the content of the cloud and the efficiency
or the yield of the nuclear detonation, nor the dangers associated with
content of the cloud and "fallout,"
Along with cumlative experience,
certain rules and formlae developed and cloud sampling became a prime
means of judging the effectiveness of each device detonated.
for determining efficiency evolved:
fire-ball measurements,
accurate,
Three methods
cloud sampling, alpha measurement, and
Cloud sampling proved by far the most nearly
Additionally, "tracer" elements were placed in the device itself
to check the efficiency of the various components; however, sampling also
gave the best readings from the "tracer"® elements and provided a means of
determining how well each integral part of the device functioned.
Los Alamos Scientific Laboratory officials have discovered no accurate
means of forecasting the behavior of a device,
Testing furnished the only
means of determining the efficiency of a device, and cloud sampling was the
most nearly positive method for this,
Secondary benefits from cloud
sampling occurred in fallout sampling, identification of particles, cloud
phenomenology, the distribution of fission products, and, sometimes,
determining alien successes with similar devices,
To provide the scientist a usable sample required three important
conditions :
(1)
It must comprise a large enough fraction of the total fission
products and "unburned" material from the device to permit the desired
measurements to be made reliably.
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