As discussed in Section 3.1.2, the distribution of gamma energies was estimated from the
visual observations of a meter on the gamma Spectrometer.
Observations at 500 and 800 feet
above Site Sally on Mohawk D + 2 showed a general response where the predominant portion of
the energy spectrum fell between 350 and 600 kev.
3.3 DISTRIBUTION OF FALLOUT
The isodose charts contained in this section have been referred to H + 24 hours and gamma
dose rate at 3 feet above the surface. The decay correction is based ont! Theflight altitude
was 300 feet for all surveys, So the altitude correction is based on a factor of 2.5.
CS
BIKINI
RONGELAP
AILINGINAE
Noutical
!
——)
Miag
{
a
165°
|
166%
an
A
J4ie
(67*
Figure 3.5 Flight pattern, Shot Cherokee D-day.
The EOB is based on a minimum detectable limit by the detector of 0.01 mr/hr. This converts to 0.025 mr/hr at the surface. Where there are noflight legs in a position to close an
isodose plot, dotted lines indicate the estimated position. The estimates are based on previous
days’ results wherever possible. Contamination enclosed within an isodose bounded area is
calculated on the basis of the average gamma intensity between consecutive isodose lines, anda
contamination density of 0.4 megacurie/naut mi? for 1 mr/hr of gamma dose rate (Section 1.3.1).
3.3.1 Shot Cherokee. The D-day flight encountered no radiation intensities above the detectable limit. The flight pattern is included to show the area searched (Figure 3.5). The D+1
flight was used for instrument check, because no contamination was found on the previous day.
3.3.2 Shot Zuni.
The D-day flight examined the region in the vicinity of the atoll (Figure
3.6). Because there was not enough data to develop isodose plots, radiation profiles have been
plotted along the flight legs.
28