DRAFT
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radiation to 25 cpm.
The sample plenchet was mountcc ina
plastic and aluminum shield to reduce scattering anc
bremsstrahlung.
Gamna rediation was detected and counted with a lead shielded RCA 5819 photomultiplier tube and a 14 inch diameter scdium
iodide scintillation crystal.
Both beta and gamma counters
were connected to a decade scaler.
Gama energy spectrum
studies were made with a vell type scintillation counter, single
channel pulse height enalyzer, and @ decade scaler.
2e2
SAMPLE PREPARATION AND COUNTING
The samples to be counted for radioactivity wore weighed,
dessicated, dried at 110°C, in sowe cesses ashed, and counted
on aluminum planchets.
The self-abserption veriation due to-
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ct
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caused some diffi
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differences in rass and density of the varicus tyres of saunies
enificantly affected by self
sbsorption in samples of thesc thicknesses, gamza radiation is
use@ in this report as 2p indication of the agucunt ef readio-«
gotive elements present.
“he ratio af sunma rays
ieies hes not been accurately devernined
roughly 1 to 2,
The activity of the seuples wes compared with the activity
of calibrated standard sources. The instrunent becksround was
subtracted and the counts corrected to agree with the standerd
source.
The values are reported as gamma reys emitted per
ninute per unit mass ef voluue cf sample abbreviated, cpm/g or
epm/e.
The prebable error in each counting rate was diffienlt
to meintein-at a constant level.
of
oa
ik
In the case ef the water and
/¢
ES