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FERBER
Through the use of this technique, it may be possible to greatly reduce
the amount of radiochemical analyses which would be required to obtain a reliable inventory of radioactivity in a nuclear cloud. This type
of monitoring might be particularly well suited to clouds from large
nuclear cratering detonations such as those contemplated for the PlowShare program. Such clouds should be visible for at least several hours
and would probably be confined to the troposphere.
Tentative answers have been found for the questions that led to
Project Stemwinder, but large uncertainties still exist. The experience
gained in the project indicates that for air bursts the lower stem should
be monitored soon after cloud stabilization while it is still visible and
that several penetrations should be made at each altitude to ensure that
representative readings are obtained. Additional data are particularly
needed for yields in the megaton range.
An obvious limitation of Project Stemwinder was the aircraft ceiling of 50,000 ft. A determination of the amount of debris initially stabilized in the troposphere requires sampling to an altitude of 60,000 ft.
Aircraft with the capability of operating at this altitude have been used
for cloud sampling, but they were not available for Project Stemwinder.
The following recommendations are offered for any future operations:
1, A continuous-recording gamma-intensity instrument package
with a range from 1 mr/hr to 1000 r/hr should be used for aircraft
cloud penetrations.
2. Experimental determination of the dose-rate reduction due to the
aircraft should be attempted.
3. An attempt should be made to monitor the entire cloud from alow- or an intermediate-yield detonation. Thus the distribution of activity throughout the cloud can be ascertained, and the total computed
activity can be compared with the fission yield of the device asa
check on the method.
ACKNOWLEDGMENTS
Project Stemwinder was originally conceived and coordinated by
Joshua Holland, Chief, Fallout Studies Branch, Division of Biology and
Medicine, U. S. Atomic Energy Commission, whose vigorous efforts
brought the project into being in the space of a few weeksprior to the
start of Operation Dominic I, The ideas and efforts of the late A. Vay
Shelton, Lawrence Radiation Laboratory (Chief, Hazards Evaluation
Branch for Dominic I, Joint Task Force 8) and of Robert J. List,
Kosta Telegadas, and Jerome L. Heffter, Atmospheric Radioactivity
Research Branch, U. S. Weather Bureau, were instrumental in planning
and carrying out the project. The excellent cooperation and high skill
of Paul Guthals, Los Alamos Scientific Laboratory, and Harry Hicks