Transmission of gamma radiation through heterogeneous media

The Attenuation of Gamma Rays

“…The principal merit of the method is that it is easy to apply; obviously, it should only be used with caution. (c) Broder's Formula A more refined approach to the multi-layer problem is that of Broder and others (1962). Here an attempt is made to allow for the passage of the photons through the previous layers, by assuming the buildup contribution of each layer is additive and that it can be found as a result of a simple differencing procedure.…”

An Approximate Transmission Dose Buildup Factor for Stratified Slabs

“…When the attenuation coefficient of the material possesses a minimum value at a certain energy E', -such as in the case of lead, we propose using E' as source energy Eo. When both sides of Eq. ( 1 ) are multiplied by eX,+Xz/R,, we have the empirical formula for the transmission dose buildup factor: B,,,(Eo;X" X,) =B,(Eo;X,+X,)+(B,(Eo;X,) ( 2) where K(x,) is a correction factor for the error accruing to the definition of p. and to the assumed energy spectrum at the region 10 MeV and various stratifications up to a total slab thickness of 6 mfp. We assume K(x,) to be represented by e-<il-tLo)x,, so as to approach the present calculations to the Monte Carlo results.…”

“…From the foregoing treatment, the empirical formula ( 2) reduces to B 1 ,,(Eo;X,,X,)=B,(Eo;X,+X,)+(B,(Eo;X,) -B 2 (E 0 ;X 1 )Je-2Cfi-p.olxzB 2 …”

Transmission of Gamma-Rays from 60Co Monodirectional Source through Slabs of Polyethylene and Iron

“…They have mostly measured dose buildup factors using ionization chamber<o-cal or plastic scintillator (4) (5) Whyte< 6 ' has measured scattered 7-rays emerging from a concrete surface containing a 6°C o point isotropic source, using a collimated two crystal scintillation spectrometer. Theus, eta!Y' have observed 7-rays penetrating through water by means of a scintillation spectrometer, and converted the pulseheight distributions into energy spectra utilizing the response function of the scintillator.…”