a
Thus from (2) ami (3),
D+ eypd = 55H pqultay(t)
m
oeseaoeveveewe
6
(4)
A(t)
Equations (2) and (4), when solved, give the activity of the tissue at any
tine and the total dose received.
From ref (3), A(t) is of the forn
y(t) = Ket - xe At
with
k 7 0.0205
ky = 0.00359
eeecevteeneos
(5)
& = time after fission, days
A, = 0.0855 , = 0.554
The first term in the above ie due to the radioactive decay of T", while
the second term - and a third term whieh was neglected since it is small
after 3 hours - allow for the contributions from ether decay chains to
the D4 actavity. (The second term also falls to a negligible amount
by 4 days, but is ineluted).
A(t) 4s of the form A(t) = kt” n
Where k « 6170, n = 1,12 fort .&hre
(Ne B. Ballon).
Sinse an initial uptake is to be determined, a time t, = 305 bre is taken,
at which both u(t) and A¢t) are known. Then, letting E = 0.20 Mev. m = 12 mm,
he may define a quantity
Ry © aaylt)
,
And the rateof nfaleof
t)
R(t)
Also,
ky = SB «1
eoceoveevvuevnseennseveeve (6)
>
BA,(t)
«9 R
a a a a a 2
(7)
and letting Ar ¢ b = 2d, as in ref (1), there results for equation (2)
TOS ARCHIVES