jaa
shown in Table 1.2.
For omnidirectional detectors, the expression is:
2/0
oe
3)
PARLE 1.8 CALCULATED BUILDUP FACTORS
The buildup factor (3) given here is the factor BL {(iP, Ry) a0
computed by Nuclear Development Associates for AFSwP (Reference §).
—+
ERENT
lev
29.3
16.2
1
5.0
19.2
3-35
3.85
;
,
s
2.97
b.00
7.00
30
2.70
2.0)
2.9
~t
3.h drodynamicEfect. As showin Section 1.3.3,Wieattenta=
Li Ry
tion ef gaum radiation is highly dependent on the amount of absorber
between the source and the detector.
For weapons of less than 100-kt yield,
estentially all ef the initial gamma radiation is emitted befere the sheck
frent can produce an appreciable change in the effective absorytion of the
air between source and detector.
For high-yield devices, the velocity ef
the shock front is sufficiently high to preduce a strong enhancement ef
a lerge percentage of th: initial game rediation (Reference 11).
. higher the yield, the larger is this percentage.
of the hydrodynamic effect follows.
fhe
A simplified treatment
ST. LOUIS FRC
Assvme a gphere that has a volume ¥, and radius R, and is filled
with a gas of density (, end mass M. Then,
Ma Volo = ATRL
3
(1.8)
cae
—
ACI O
aa