rep at 30 yd.

This dose decreased to 32.2 rep at 600 yd.

Along the long

axis, the dose varied from 6360 rep at 30 yd to 22 rep at 600 yd.
Project 2.9, Gamma Dose Measurements, was a new project approved

for the shot. Its
time and distance
NBS film badge.
total gamma dose

objective was to measure gamma dose as a function of
from the device. The basic type of instrument was the
The film badges were displayed along ground lines to give
versus distance. Also, they were used in film dosimeter

transport devices which exposed individual film badges for known time periods.

The periodic exposure of film badges over an extended time interval permitted a determination of the initial and residual dose rates. Film badges are
being processed and data are not available at this time.
Project 2.10, Residual Radiation, was also created specifically for par-

ticipation on Quince and Fig and had the objective of documenting the residual

gamma field intensities produced by the surface detonation of the device.
The required data were obtained by means of radiological surveys conducted
both on the ground by monitoring teams and from the air by means of a
probe lowered to a 3-ft height from a helicopter.

The results indicate the

radiation intensities at the lip and crater of shot Fig were above 10,000 r/hr

at H + 30 min, which would necessitate avoidance of this area by troops advancing at an early time. The area contaminated by fallout to levels of

military significance was less than expected by a factor of 2.5 according to
the present scaling laws.
The early decay measurements show that the normal fission product

decay rate, t~!?, is not applicable for a period from H + 1 to H + 3 hr.
Instead, the decay rate is t~!-*, which is faster. However between H + 3

and H + 24 hr, the decay rate was only t~°™ which is slower than the normal fission product decay rate.

os
The third newly approved project, Project 2.11, had the mission of

making gamma, neutron, and thermal measurements as a function of altitude

for this event. A polyethylene balloon was moored 300 ft from ground zero,
and appropriate instrumentation was exposed at various altitudes up to 1500

ft by attachment to the balloon mooring cable.

Fission foils were too active

to count at the EPG and will be counted in the ZI. Film for gamma dose
measurements is being developed. Due to mechanical difficulties caused by
adverse weather conditions, no thermal measurements were made.
Project 8.7, Thermal Measurements, measured the radiant exposure

in cal/em? and the thermal irradiance in cal/cm?/sec at various distances

from surface zero for the subkiloton device. Instrumentation consisted of
seven CWL Thermistor Calorimeters located from 150 to 600 ft from surface zero; two NRDL Disk Calorimeters located at 450 and 900 ft from surface zero; and four NML Radiant Exposure Meters located at 350, 450, 600,

and 750 ft, respectively.

The CWL instrument data were recorded in an

instrument shelter 1200 ft from surface zero; the NRDL instruments were

self-contained. No data are presently available from the NML meters, which
have been forwarded to NML for reading and calibration. The CWL Ther39

om
APWUHE:

38

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