The gamma-ray and neutron shielding factors of fly-ash brick materials

Abstract

A comprehensive study of gamma-ray exposure build-up factors (EBFs) of fly-ash brick materials has been carried out for photon energies of 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path) by a geometrical progression (GP) fitting method. The EBF values of the fly-ash brick materials were found to be dependent upon the photon energy, penetration depth and chemical composition, and were found to be higher than the values for mud bricks and common bricks. Above a photon energy of 3 MeV for large penetration depths (>10 mfp), the EBF becomes directly proportional to Zeq. EBFs of fly-ashes were found to be less than or equal to those of concrete for low penetration depths (<10 mfp) for intermediate photon energies up to 1.5 MeV. The EBF values of fly-ash materials were found to be almost independent of Si concentration. The fast neutron removal cross sections of the fly-ash brick materials, mud bricks and common bricks were also calculated to understand their shielding effectiveness. The shielding effectiveness of the fly-ash materials against gamma-ray radiation was lower than that of common and mud bricks.

Investigation of Gamma and Neutron Shielding Parameters for Borate Glasses Containing NiO and PbO

“…The effective removal cross-section of compounds and homogenous mixtures is calculated using the value of Σ (cm −1 ) or Σ / (cm 2 /g) of the elements in the compounds by mixture rule [4]. The detailed calculation procedure for Σ can be found various recent literatures for alloys [15], fly-ash brick materials [16], bismuth borosilicate glasses [17], oxide dispersion strengthened steels [18] and building materials [19]. The Σ / values of elements have been taken from Kaplan and Chilton [20,21].…”

Shielding efficiency of metal hydrides and borohydrides in fusion reactors

“…The buildup of pho tons is mainly due to mul ti ple Compton scat ter ing, and for a com pound or mix ture it can be char ac ter ized by an equiv a lent atomic num ber Z eq . The buildup fac tor of a given ma te rial can be calcu lated in a three-step pro ce dure [5,6,8,11,12,13]. First, Z eq is cal cu lated by log a rith mic in ter po la tion using the ra tio, (µ/r) Compton /(µ/r) to tal .…”

“…Var i ous re search ers have used geo met ric-progres sion (G-P) fit ting to de ter mine gamma ray buildup fac tors for al loys [6], fly-ash ma te ri als [8], con crete shield ing [5], brick ma te ri als [9], gas eous mix ture [10], thermoluminescent dosimetric ma te ri als [11], heavy metal ox ide glasses [12], and hu man or gans and tis sues [13]. These stud ies show that G-P fit ting is useful for es ti mat ing buildup fac tors.…”

Shielding efficiency of lead borate and nickel borate glasses for gamma rays and neutrons

“…Authors [9] developed a fitting for mula, called Geometric Progression (G P) which gave buildup factors of the good agreement with the ANS, 1991. Various researchers investigated gamma ray buildup factors of different materials such as fly ash brick materials [10], alloys [11], optically stimulated luminescence materials [12], bismuth borosilicate glasses [13] and oxide dispersion strengthened steels [14]. These studies show that this G P fitting method is suitable for computation of the buildup factors.…”

“…The mass attenuation coeffi cients of the elements were generated by using WinX Com [7]. The G P fitting method has bees standard ized [10][11][12][13][14] by comparing EBF values of water with ANS, 1991 [8] and MCNP 5 [18]. The Z eq and G P fitting parameters for one borate glass sample (S 1 ) are…”