ee
EVENT AND
DESCRIPTION OF EXPOSED GROUPS
9
source’ beam wir doses with comparable biologic effect are obtained:
relationship to the surface dose and depth dose
as does the air dose measured in a “point source”
beam in the clinic or Jaboratory. It would
appear under these circumstances and in most
experimental conditions that the midline dose,
Rongelap. Group I___----Aiinginae, (rroup IJ__2---_Rongerik, Group LIT ____--
rather than dose measured in alr, would be the
Utirik, Group IV_.2..------
26U r
100 r
120 r
20 or
100
3
8
h
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<f
r |
4e7 EXPOSURE,
2
|
<
w~SCO
MANY SOURCES
ra
:
135
lamer
atone
Wi
+
oO
oS
=
a
rs
4
a:
RATION 56
~™NN
lad
lw
a
4
j
]
LS
nn
BILATERAL EXPOSURE,
DIVERGING SOURCE
.
39%
\
OW
10
oN
h
o
5
iO
15
20
25
30
.
36
CM MASONITE
DEPTH OOSE DISTRIBUTION IN CYLINDRICAL PHANTOM, co FACILITY, (NMR?)
Fictre 1.4—Counparison of depth dose curves tn maeasontic phantoms fron
julateral exposure to d atngle point source, and sunullancous erposure fo
minudiiple sources icith a epkerical diugtritution @raund the phantom.
better conumon parameter in terms of which to
predict biological effect. On this assumption,
the air dose values stated in Table 1.1 should be
multiphed Gy approximately 1.5 in order to
compare their effects to those of a given air
dose from a “point source” beam geometry delivered bilaterally. If this is done, assuming
a fallout of 12 hours, the following “point
wend
Cc
ch.
481712 O-—%6-——2
The geometry of radiation from a fallout field
is not identical either to the geometry of biJateral point sources or spherically distributed
sources since the pline source delivers the radiation largely at a erazine angle. However, thie
total field situation is better approximated by
solid than by plane geometry.
Exposure geoim-
etry in a radioactive cloud would be spherical.