en
”
biology gamma field at the Brookhaven National
Laboratory and made use of a point source,
nanely, two killicuries of cobalt 260, and
erected a narrow penoil of a lead shield to
eliminate the primary beam,
We vent out to the 275 meters and
made measurements of the direct radiation and
that ig the direct radiation with the shield
removed and the scattered radiation with the
shield in place,
This ig a point source and then it
was just a simple matter of integrating around
over a plane in order to get the dose rate
from a distributed source.
This 4g the Brookhaven gamma field
measurements,
We again used the very good
chamber of Doctor Failla and the points co=
incide essentially as they should for gamma
radiation and one can see that the direct
plus scattered beam measurement and this are
approaching closer together until when one is
out to the maximum distance that we went out
- 275 meters, the scatter contribution was slightly
in excess of 50 per cent of the total.
DR. FAILLA:
did you have in that?
How much of a shadow
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