Test Site.
These were Castle - 1954,
Redwing - 1956,
and
Hardtack - 1958.
MATERIALS AND METHODS
The visits to the islands were made possible by the
cooperation of Task Force 7.1 and the Trust Territory of the
United States.
Two to five-man teams were flown to the
islands to collect samples which were refrigerated,
to the Eniwetok Marine Biological Laboratory,
returned
dissected,
é
weighed, dried, packaged and then sent to the Laboratory of
Radiation Biology,
Sing and analysis.
Seattle,
Washington,
for further proces-
The samples were prepared on 1.5-inch
Stainless steel planchets and counted for gross beta radio-~
activity in either one of two counting systems operated in
the Geiger-Muller. region:
(a) One and one~-half-inch end-
window "pancake" type Anton tube in a jJ-inch lead Anton
shield connected to a Nuclear Chicago Model 181 scaler and
equipped with an automatic sample changer.
This system has
a background of about 18 counts per minute and an efficiency
Of approximately 12 per cent based on «40,
(b) An internal
counting chamber continuously flushed with methane in a
Radiation Counter Laboratory Nucleometer Mark 9,
Model 3.