AdsorptionAiz. The absorption of unscattered ganz
Fadiation in air is exponential with distance.
From a point source
of moncenergetic radiation, the variation of intensity with distance
4s expressed ast
I=
10Pleas
dD
wheres
G2
I, = intensity at distance D
1
= ecurce intensity
He
=
total linear absor-tion coocficiest (us
coefficient generaliy decressts wil. incre 5.ng
gamma energy)
D=
distance
“€
ne absorption coefficient » in Equation 1.2 is ap, licable fcr
Blin
gee irs € ee € GCourretticn Asal me bl fg.
Te
ditions wher tie detectes is a-oroxiaeicit; @ & sons. clam
Tris is done by adding @ buildup factor i Ww cation 16° t% account
for the scactcerce radiavion that wili be dececoul.
buladus sucker.
for different eneryios anc disiawes have peen calcucatei Velicescc 6!,
arm! some values are shown in Table 1.2.
For amicircctionc: aciuciors,
the expression is:
1. = Taefae”
(1.3)