And if the water is uniformly contaminated to the depth Z centimeters, the total amount lp of activity In
the water column per square centimeters, is
.
Ip = Zem Iz
= 16.5 Zom $4 = Mev/cm?/sec
This can be imagined to correspond to the fallout density on a smooth, fixed plane, at timet.
If the fallout has several constituents, the fallout density can be expressed
Ip = >> njEj
i
And if P; = the fraction of energy in the ith component
mE; = Pyle
so that
the dose at elevation X due to the ith constituent is,
sEsha
/E;
—-s
nd; = ae | nll ds By; (jc Xx) = Mev/cem?/sec
8
“ux
and the total dose in air is,
Sa [ A! fae a or
niEjha(E;)
4
4
eo
e*
“px
or by substitution, the total dose at elevation X is, in Mev/em*/sec,
ha ©)
e®
ea
[ax ve8
t
“ux
or,
.
wo
.
-8
16.5 Z¢ >» PihaEi) / ode By (ue x)
7
2
8
“px
Therefore a dosimeter at elevation X above the hypothetical plane would read, at time t, and in milliroentgens per hour,
6 = 1.45 x 1075 (1000) (3600) > njd;
= 52 y nye;
Ps
= (52) (16.5)Z¢4 D> Pyha (Ep f e8 ds B; (te x)
i
“px
89