—
ments
ence has indicated
at a height of three feet. fast field experi
e
ion-ty;
g
survey meters at ground level
that the gamma readin from ionisst
measure
is about S$0f higher than at three feet.
re
Therefo
if it be assuced that
ent
l
@ ground level gamma reading of a survey netar is equiva
dose rate, the ratio of beta dose rate at 7 xg/ce*
Shree is about 2K te
to gamma
to « surface
Gose rate at
1.
Another approact to estizating the retio of beta dose rate at 7 mg/cx*
to gamxa
dose rate at three fest is as fcllows.
Assuring a uniform distri-
bution of 1.0 megacurie per square mile of gamma activity, the dose rate
resting from an infinite fiald is about 4 1 roentgens/hour,® Calculations
given in appendix B indicate thet a like soncentration of fallout material
will produce about 430 reps/hour at 7 mgr.
This suggests a deta to
gama ratio of about 1% to 1 whieh is about a factor of two lover than
the first approech.
added support to tis latter method of estinating
beta doses is found {n appendix
C,
Such eonsiderations may be fraught with pitfalls.
above
Por example, the
discussion implies a unifore distriinmtion of falbut eatertal.
Obviously,
this is not correct but how far this deviates from the facts and to what
extent this influences the results is
difficult to assess.
indicate that the production of recognisable beta burns
particle requires a high specifie activity.
Calculations
from a single
{Ses Policy III for discussion.)
It nsy/e,hovever, that the particles of fallout are @lose enough to have
overlapping of rediation fields and thus require signifleantiy
opecifie activity af the particles te orc ture beta burns.
**Effects of Atoni2
bearons™,
155°
lover
This hypothesis