11
The totel correction fectors to convert counts per minute to
disintezrations per minute were 3.5 for plankton,
and 3.3 for filter papers.
4.0 for water,
Nezgetive values are given wherever
tne count was less than bacxpround.
No correction vas made for
decay sirce the counting was done essentially immediately after
collection
tion.
and the values given are as of the time of collec-
Decay curves are shown in Figure 2.
Gemma Rey Spectra.
Ganmmeé ray spectra were min at the Uni-
versity; of Washington laboratories in Seattle on a single channel, Sutomatic advance. gemma spectrometer.
The spectrometer
consists of a Nuclear-Chicago Model 18190 radiation analyzer,
a
Nuclear-Chicago Model DS-3 scintillation well counter, a Trecerlet Superscaler, a Nuclear-Chicago Model C-111 printing timer,
and an automatic baseline advance device built at Seattle.
Spectrum ranges of 0.5, 2.0, and 4.0 MEV were used.
RESULTS OF SURVEY
Plankton
The highest value of rudioactivity in plankton, 21,000
d/m/a@ wet, was found at station 55 sbout 80 miles north of Eniwetok and the lowest value, 27 d/m/g, was found immediately south
of Guam.
This lowest value was slightly lower than the value ob-
tained near the same station during Operation Troll (39-61 d/m/g),
indicating that Guam was near the westernmost extremity DOBWRCHIVES
radioactive contamination which resulted from Operation Redwing.
A slight degree of contamination is
indicated by comparison with
plankton samplea from Puget Sound and off the Queen Charlotte
a)