UNCLASSIFIED
= om ame tee ae
—
ABSTRACT
Studies were made of the structure and composition of, and
the distribution of radioactivity within, the fallout particles
resulting from a tower shot in Operation REDWING. Techniques
utilizing the petrographic microscope and X-ray diffraction
analysis were employed. Three types of fallout particle were
found. The most common type was formed by the interaction of
the vaporized iron and radioactive elements with molten calcium
oxide derived from the coral sand which was carried up into the
fireball by atmospheric turbulence. These particles consisted
of an outer zone of radioactive dicalcium ferrite surrounding
an inactive residual core of altered calcium oxide. The second
type consisted almost wholly of radioactive iron oxide and apparently was formed by the melting and oxidation of part of the
steel tower. The third type consisted of unmelted coral sand
grains which had small, black, radioactive spheres adhering to
their surfaces.
This is the sixth in a series of reports on the nature of
radioactive fallout particles:
Part I, USNRDL-374, 28 November
BREERRamperemmo Dr ere
.
ema
tee wet parse
1952; II, USNRDL-408, 1 July 1953; ITI, USNRDL-440, 24 February
1954; IV, USNRDL-TR-26, 17 January 1955; V. USNRDL-TR-133,
1 February 1957; all by C. E. Adams.
ii
UNCLASSIFIED