perpendicular to the plate.
The lines of sight of the three colli-
mator tubes passed through these three extensions,
Thirty-two
pieces of 1/8" lead sheet were cut so as to fit over the front
Blast plate, leaving three holes for the lines of sight.
The line
of sight was of course not entirely clear, having to pass through
the 3/8" steel blast plate as well as 3/4" of pt?,
An old phonex collimator block which had broken into three
pieces was used for additional shielding.
One section was placed
on edge along each side of the station and the third section was
placed across the top of the collimator.
This section was rotated
through 90° so that it was flush with the front of the station but
projected about 10" over each side,
The whole station was then
“y
covered with sand bags,
In addition to extra shielding, two bar magnets were fastened
one on each side of the radiator so that the magnetic field between
them was perpendicular to the axis of the camera.
It was hoped by
this method to reduce blackening of the plates by Compton electrons, —
This method had reen shown to reduce blackening of emulsions in
phonex cameras at the Nevada Test Site.
station were equipped with these magnets.
All cameras at the 300 yi.
Furthermore, a two inch
lead plug was placed in the 14" pipe in front of the top collimator
tube, so as to reduce the gamma ray flux down the collimator tube,
Recovery was made by Allen, Frye and two H & N men (Brennan and
Kaneshiro) late in the afternoon of Beday.. Helicopter recovery had
at.
been used after had been used acter filialGa)
(BLACKFOOT) a 6 x 6 truck was landed from a T-boat,
-
but after
.
Te
The truck carried
a heavy recovery box with 3" of lead shielding all around it, and space
inside for six phonex cameras,
COPIED/Dp
LANL RQ y
Recovery from the 300 yd. station was
.
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