fired X-unit, which, when coupled with equipment from Project 34.5, provided

a precisiowaimlayed firing signal for the Raynex experiment. The Raynex

vice was successfully detonated with the requested degree of time accuracy.
The objective of Project 34.7 participation on the Quince event was to

prompt nuclear dose rate effects on weapon materials and components.

This interest stems from the need to reduce the vulnerability of nuclear

weapons to other nuciear bursts and environments, and from observed in-

stances of variation in radiation damage criteria between in-reactor exposures

as compared with prompt nuclear bursts.
Specimens of transistors, diodes, capacitors, resistors, plastics, semi-

conducting materials, detonators, and high explosive materials were exposed

to prompt nuclear dose rates in the range from |
The effect
produced in these specimens will be compared to effects produced in similar

specimens exposed in reactors to the same total neutron dose at much lower
rates.

The aims of Project 34.8/2.14e were: (1) to make the necessary meas-

urements on Quince event to delineate the fallout gamma radiation yield pro-

duced by a land surface detonation of a fission weapon with a yield between
'(2) using data collected by this project and by Projects
%.9 and 34.10, to construct a fallout model for use with any wind pattern

and evaluate extremes in militarily significant intensities for the same yield
range; and (3) to define the attendant plutonium contamination problem.

The site for Quince event was Runit (Yvonne) Island of Eniwetok Atoll.

Only about 400 ft of land in the prevailing downwind direction was available
for radiation monitoring, necessitating placement of bulk of the instrumenta-

tion in the lagoon. There were 92 lagoon stations, 46 land stations, and 8
reef stations. The bulk of the fallout instrumentation consisted of sticky pan
fallout collectors. These were mounted on small buoys in the lagoon and
on steel pipes in the reef area.

After exposure, the pans were counted in

a fixed geometry. Lagoon and reef pan readings were calibrated in terms
of full yield intensities by dose rate measurements over the available land
and flat-topped barges which were anchored in the lagoon.

Dose rate read-

ings on land and on the barges were made by hand-monitoring and by automatic recording instruments.
Since Quince:

it was decided to

measure fallout from Fig, using the same array of instrumentation.

Fig

event produced fallout intensities greater than 100 r/hr at H + 1 hy, covering an area which extended 100 ft upwind to less than 1000 ft downwind and

150 ft crosswind. Beyond 400 ft upwind and 2600 ft downwind, intensities
were less than 1 r/hr at H + 1 br.
Project 34.9/2.14b was responsible for photographing the cloud produced
by the Quince and Fig events. The main objective was to determine the
cloud dimensions as a function of time.

These measurements were necessary

to assist Project 34.8 in constructing a fallout model.

That produced by Fig stabilized at 5400 ft approximately 6 min
after zero time. Maximum diameter was 1900 ft, stem height was 75 per
cent of the total height, and the puff diameter was 1.35 times that of the stem.
One of the objectives of Project 34.10/2.14c was to measure the preshot wind conditions over expected cloud heights for Quince and Fig so that
shot time could be set to assure that expected fallout would be adequately
sampled by the instrument array of Project 34.8. A second objective was

56

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