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Abstract In this paper, we studied the gamma photon attenuation properties for different germanate glasses systems with composition Sb 2 O 3 –GeO 2 –SiO 2 –Al 2 O 3 , TeO 2 –WO 3 –GeO 2 , GeO 2 –TeO 2 /SiO 2 –PbO–CaO–Tm 2 O 3 and B 2 O 3 –GeO 2 –Gd 2 O 3 –Eu 2 O 3 –GdF 3 –BaF 2. The mass attenuation coefficients (μ/ρ) for the selected germanate glasses were calculated at different energies (between 0.015 MeV and 15 MeV) using the MCNPX code. The calculated MCNPX μ/ρ values then compared with the WinXCom data to check the accuracy in the results. The results showed that the Sb 2 O 3 replacement by SiO 2 causes a decrease in μ/ρ for Sb 2 O 3 –GeO 2 –SiO 2 –Al 2 O 3 glass system. Also, it is found that for TeO 2 –WO 3 –GeO 2 glass system, μ/ρ decreases as GeO2 content increases from 1 to 20 mol%. While for GeO 2 –TeO 2 /SiO 2 –PbO–CaO–Tm 2 O 3 glass system, the results revealed that the glass samples contain TeO 2 possess higher μ/ρ values than the samples contain SiO 2. For the B 2 O 3 –GeO 2 –Gd 2 O 3 –Eu 2 O 3 –GdF 3 –BaF 2 glasses, we found that the μ/ρ values decrease as BaF 2 is increased from 0 to 15 mol%. Moreover, it is found that 50Sb-0Ge for series 1, TWG0 for series 2, 2G4T for series 3 and X = 0 for series 4 glass samples among the studied glasses have the highest effective atomic number values. On the basis of the results achieved, 50Sb-0Ge, TWG0, 2G4T and X = 0 samples have the best radiation shielding characteristics among the selected glasses. Highlights • Radiation shielding characteristics of different germanate glasses have been investigated. • The μ/ρ for the selected germanate glasses was evaluated by MCNPX simulation code at different energies. • The HVL results for the present germanate glasses suggested that the gamma photons absorption capacity increases as the density of the sample increases. [ABSTRACT FROM AUTHOR]

In the present paper, a universal analytical dependence of effective atomic number on the composition of matter and radiation energy is proposed. This enables one to consider the case of a strong difference in the elemental composition with respect to their atomic numbers over a wide energy range. The contribution of photoelectric absorption and incoherent and coherent scattering during the interaction between radiation and matter is considered. For energy values over 40 keV, the contribution of coherent scattering does not exceed approximately 10% that can be neglected at a further consideration. The effective atomic numbers calculated on the basis of the proposed relationships are compared to the results of calculations based on other methods considered by different authors on the basis of experimental and tabulated data on mass and atomic attenuation coefficients. The examination is carried out for both single-element (e.g., 6 C, 14 Si, 28 Cu, 56 Ba, and 82 Pb) and multi-element materials. Calculations are performed for W 1−x Cu x alloys (x = 0.35; x = 0.4), PbO, ther moluminescent dosimetry compounds ( 56 Ba, 48 Cd, 41 Sr, 20 Ca, 12 Mg, and 11 Na), and SO 4 in a wide energy range. A case with radiation energy between the K- and L 1 -absorption edges is considered for 82 Pb, 74 W, 56 Ba, 48 Cd, and 38 Sr. This enables to substantially simplify the calculation of the atomic number and will be useful in technical and scientific fields related to the interaction between X-ray/gamma radiation and matter. [ABSTRACT FROM AUTHOR]

Due to the increasing security needs, X-ray devices have started to be used more and more in security systems. Dual-energy X-ray devices are preferred to conventional ones since they enable Effective Atomic Number (Z e f f) estimation that cannot be provided by traditional devices, which use density-based segmentation. In this paper, pure material samples are used to obtain system characteristics. Linear mass attenuation coefficients (μ) of the materials can be calculated by using two leveled images, and these coefficients provide information about the Z e f f of substances. After that, they can be classified as organic and inorganic via the effective atomic number method and explicitly identified. As well as this, organic explosives can be detected thanks to this simple and effective approach. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work was to develop a method to correct the absorbed radiation (the mass attenuation coefficient curve) in low energy (E <30keV) applied to a biological matrix based on the Rayleigh to Compton scattering ratio and the effective atomic number. For calibration, scattering measurements were performed on standard samples of radiation produced by a gamma-ray source of 241Am (59.54keV) also applied to certified biological samples of milk powder, hay powder and bovine liver (NIST 1557B). In addition, six methods of effective atomic number determination were used as described in literature to determinate the Rayleigh to Compton scattering ratio (R/C), in order to calculate the mass attenuation coefficient. The results obtained by the proposed method were compared with those obtained using the transmission method. The experimental results were in good agreement with transmission values suggesting that the method to correct radiation absorption presented in this paper is adequate for biological samples. [Copyright &y& Elsevier]

Abstract: The effective atomic number (Zeff ) and electron density (Nel ) of hydroxyapatite (HA) and cortical bone have been computed for total photon interaction in the wide energy range of 1 keV–100 GeV using WinXCom. The variations of effective atomic number and electron density with energy of HA are compared with that of cortical bone. GP. fitting method has been used to compute energy absorption and exposure build-up factor of HA for wide energy range (0.015 MeV–15 MeV) up to the penetration depth of 40mean free path. The computed absorption build-up factor is used to estimate specific absorbed fraction of energy (Ф) and relative dose of photon in HA. Build-up factor increases with increase of penetration depth. The results of the present paper will also help in estimating safe dose levels for radiotherapy patients and also will be useful in dosimetry and diagnostics. [Copyright &y& Elsevier]

In this paper, we report the effective atomic number of some H, C, N and O based sugars and amino acids. These have been determined by using a handy expression which is based on the theoretical angle integrated small angle (coherent+incoherent) scattering cross sections of seven elements of Z ≤ 13 in four angular ranges of (0–4°), (0–6°), (0–8°) and (0–10°)for 241 Am (59.54 keV) and 137 Cs (661.6 keV) gamma rays. The theoretical scattering cross sections were computed by a suitable numerical integration of the atomic form factor and incoherent scattering function compilations of Hubbell et al. (1975) which make use of the non-relativistic Hartree–Fock (NRHF) model for the atomic charge distribution of the elements in the angular ranges of interest. The angle integrated small angle scattering cross sections of the H, C, N and O based sugars and amino acids measured by a new method reported recently by the authors were used in the handy expression to derive their effective atomic number. The results are compared with the other available data and discussed. Possible conclusions are drawn based on the present study. [ABSTRACT FROM AUTHOR]