Riferencs 14.
Degradation of these six spectra dv penetration of about 1 inch of stee] was also estimated
Ar unaticnaated gamma-cenerg: spectrum (broken inte n energ, intervals; has an average ¢nerg flux
er’. Mey em*-see for the ith energy interval D, Mev wide. After attenuation by x-cm of steei the ener.
Fane
amoth. oth energy interval has been reduced to U,B, exp (ux). assuming plane monodirectional ramon
11
simpheity, where B, 1s an energy-buildup factor determined by cross-interpolation in Reference
ana u is tm total absorption coefficient per centimeter of stee] iat the energy representative of the ith
-.al) determined from Reference 15.
To reduce the computational complexity. it was assumed that
roy energs originating in the ith energy interval) the attenuated energy flux per unit energyinterval he-
]
came umiforml, distributed over the interval = Dj.
.
emphasizing the low energies (Figure B.10).
the ith interval. is represented by
(0
2
This assumption biases the results somewhat by over-
The energyflux for the pth intervals (pj). originating from
}
0s) U,B) exp !-ux)
(B.li
Summing all of the attenuated and degraded energyflux (Ap! for the pth energyinterval. originating from
all intervals that can contribute lo it. results in
-
Ap = Dy =
ie exp ‘-vs]
Dj
1
(B.2)
Ancxample of the effect of this assumed degradation on one of the assumed gamma-energn spectra is presumed in Figure B.11.
The energy flux for each of the energy intervals of the twelve energy spectra (six original and six de-"
graded) was converted to an equivalent dose rate by using conversion factors determined from Reference
is
These dose rates were used to calculate percent dose-rate contributions from energyintervals representative of the energies at which the integrated detector responses had been calculated (Tables B.7 and
B.>). These percentages were used as weighting factors applied to the data of Figures B.6 through B.9.
therebv obtaining the overall responses to the assumed spectra in relationship to the hiased-fieldcalibration. GITR bias-correction factors were obtained by averaging the reciprocals of the weighted
integrated responses to the assumed energyspectra for the various idealized radiation-source geometries
Table B.9),
88