Effect of Gamma Ray Energies and Addition of Iron Slag by weight to Portland Cements on Mass Attenuation Coefficient

Transcription

1 Journal of Materials Science and Engineering A 3 (12) (2013) D DAVID PUBLISHING Effect of Gamma Ray Energies and Addition of Iron Slag by weight to Portland s on Mass Attenuation Coefficient Abd El-Latif Abd El-Ghany Abd El-Latif Ahmed 1, Khalifa S. Saeid 2, H.S. Ragab 1 and A.A. Abdalla 2 1. Physics Department, Faculty of Education in Al Areish, Sues Canal University, Egypt 2. Physics Department, Faculty of Science, Omar El-Mukhtar University, El-Beida, Libya Received: June 08, 2013 / Accepted: July 12, 2013 / Published: December 10, Abstract: This paper presents values for density, linear attenuation coefficient and mass attenuation coefficient experimentally in addition to theoretically by using X-Com program (Version 3.1), of Portland cement without and with different percentages of iron slag by weight (5%, 15%, 25%, 35% and 45%). Measurements were carried out using a collimated beam of gamma ray from point sources (Co-60, Cs-137, and Na-22), and sodium iodide (1.5\\X1.5\\) crystal with cassy-gamma ray spectrometer. From the experimental results, it was found that the mass attenuation coefficients have been increased with increasing the addition of iron slag, in addition the theoretical calculation of mass attenuation coefficient. It is also found that there are deviation between experimental values and theoretical calculation for all cement samples this is due to the experimental errors. Key words: Mass attenuation coefficient, gamma ray energies, cement, gamma ray, shielding, iron slag. 1. Introduction Study of the flux attenuation of γ-ray in materials widely used for radiation shield design, is of great importance from the point of view of radiation damage, heating effect, and dose calculations at the outer side of the shield. Shielding materials such as steel, water, and graphite are the most widely used around the core shield of nuclear reactors [1]. The hydrated cement provide a large fraction of the hydrogen content of the shield. The overall shielding effectiveness of a concrete does not depend at all sensitivity on the hydrogen content, provided it is above a certain minimum value. A hydrogen content of the order of 0.5 per cent by weight of the final mixture is satisfactory in this respect, and this is a figure which can easily be reached without departing from normal Corresponding author: Abd El-Latif Abd El-Ghany Abd El-Latif Ahmed, Ph.D., professor, research field: nuclear radiation shielding. Latif2610@yahoo.com. engineering practice. By far the commonest cement is Portland cement, which consists of calcium silicate and calcium aluminate, formed by calcining a mixture of chalk and clay. When hydrated it contains about 13%-16% by weight of combined at room temperature [2]. With increasing use of γ-ray active isotopes in industry, medicine and agriculture, it has now become necessary to study mass attenuation coefficients in various materials of technological and biological importance. There is always a need to develop material, which can be used under harsh conditions of nuclear radiation exposure and can act as shielding material. For nuclear radiation shielding, a larger quantity of shielding material is required, therefore, study of propagation of radiation flux in shielding materials is essential requirement for shielding design. Major mass of nuclear radiation shield consists of layers of different concretes with different

2 Effect of Gamma Ray Energies and Addition of Iron Slag by weight to Portland s on Mass 839 compositions and densities, but considerable variations in water contents in concrete add uncertainty in calculation of attenuation coefficients. With the development of theoretical tables and computer program (XCOM) for calculation of mass attenuation coefficients, it has now become possible to make a meaningful comparison between theoretical and experimental results. Materials to be used for shield design should have homogeneity of density and composition [3]. Some previous works in the field of radiation shielding were done and published using different shield materials, different geometries and different nuclear radiation sources [4-12]. In the present paper, samples of cement without and with different percentages by weight (5%, 15%, 25%, 35% and 45%) of iron slag were prepared, it has been undertaken to evaluate the former samples as γ-ray shields. Experimental values of mass attenuation coefficients have been compared with theoretically calculated values of these samples using XCOM program [13]. 2. Experiments 2.1 Materials and Sample Preparation The cement sample without iron slag was attended from cement factory in El-Fataeih, dernah, Libya. In civil engineering department, faculty of engineering, Omar Al-Mokhtar University, El-Beida, Libya, the cement mixed with different percentages by weight (5%, 15%, 25%, 35% and 45%) of iron slag. To study the nuclear attenuation properties, cubic samples (5 5 5 cm) were prepared. The chemical analyses of Portland cement given from cement factory in El-Fataeih, Dernah, Libya is given in Table 1 in addition there is a chemical analyses of iron slag from musrata factory for steel in Libya (Table 2). 2.2 Measurement of Gamma Ray Intensity An experimental set up of narrow beam geometry is Table 1 Chemical analysis of Portland cement. Serial No. Parameter Weight (%) 1 SiO Al 2 O Fe 2 O CaO MgO SO K 2 O 1.18 Table 2 Chemical analysis of granulated blast furnace slag (iron slage) of Musrata in Lybia [14]. Compositions Wt.% SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO the best method to determine the linear attenuation coefficient µ. The distinctive feature of narrow beam (i.e., one having the so called good geometry) is that only the source radiation, which traverse the specimen absorber without experiencing any interaction of any kind, reach the detector. For example, any scattered radiation is prevented from reaching the detector [15]. The attenuation coefficient of samples under investigation has been determined by the usual attenuation equation: I = I 0 e - µx where, I is the gamma ray intensity after the shield material, I 0 is the gamma ray intensity before the shield material, µ is the attenuation coefficient factor, and x is the thickness of the shield material [16]. Gamma ray intensities behind cement samples with different percentages by weight of iron slag have been measured. Measurements have been carried out by using collimated beam of the point isotropic γ-ray sources 137 Cs with one line of energy Mev. 22 Na with two lines E 1 = Mev, and E 2 = Mev in addition to 60 Co with two lines E 1 = 1.17 Mev and E 2 = 1.33 Mev. The leakage γ-ray intensities behind the cement samples without and with iron slag percentages by weight (5%, 15%, 25%, 35% and 45%) have been carried out by using sodium iodide crystal NaI(Tl)

3 840 Effect of Gamma Ray Energies and Addition of Iron Slag by weight to Portland s on Mass scintillation detector with dimension 1.5'' 1.5'' and MCA Box-Cassy γ-ray spectrometer. The transmitted intensities were measured by using narrow beam geometry, where two collimator made for lead of 10 cm length and 5 cm diameter before and after the samples used. The incident and transmitted intensities were determined for a fixed preset time in each measurement by choosing a narrow symmetrical region with respect to the centered photo peak. 3. Results and Discussion The results in the present work Show the variation of density, total linear attenuation coefficient of gamma ray, and total mass attenuation coefficient of gamma ray, experimentally in addition to theoretically using XCOM code as a function iron slag percentages by weight addition to Portland cement. Fig. 1 displays the variation of cement density with the iron slag percentages addition by weight.where the density of cement increase with increasing the iron slag percentages by weight. Fig. 2 shows the effect of γ-ray energies in Mev on total linear attenuation coefficient µ for different samples of cement without and with iron slag percentages by weight. It is shown that the total linear attenuation coefficient µ decrease with increasing the γ-ray energies in Mev, at the same time the linear attenuation coefficient µ increase with increasing the percentages by weight of iron slag. Fig. 3 shows the variation of γ-ray mass attenuation (µ/ρ) with the γ-ray energies in Mev., for different samples of cement without and with iron slag percentages by weight. It is shown that the mass attenuation coefficient (µ/ρ) decrease increasing γ-ray energies in Mev., the higher values of mass attenuation coefficient (µ/ρ) were found at cement sample with 45% iron slag, while the lowest values were found for cement sample without iron slag, i.e., the mass attenuation coefficient (µ/ρ) increase with increasing the iron slag percetages by weight (5%, 15%, 25%, 35% and 45% iron slag. Fig. 1 Effect of slag percentages addition by weight to cement on Densituy. Fig. 2 Effect of gamma ray energies in Mev on total linear attenuation coeffecients for different samples of cements. Fig. 3 Effect of gamma ray energies on total mass attenuation coefficient for different samples of cement without and with slag percentages by weight.

4 Effect of Gamma Ray Energies and Addition of Iron Slag by weight to Portland s on Mass 841 Fig. 4 represents the effect of cement samples without and with iron slag samples (5%, 15%, 25%, 35% and 45% percentages by weight) at different γ-ray energies in Mev. (0.511, 0.662, 1.17, and 1.33 Mev), where the mass attenuation coefficient increase with increasing the iron slag percentages by weight. The highest values of mass attenuation coefficients (µ/ρ) found at the lowest energy Mev but the lowest values were found at the highest energy 1.33 Mev. Fig. 5 displays the dependence of mass attenuation coefficient (µ/ρ) theoretically using XCOM program and experimentally on iron slag percentages by weight addition to Portland cement, at γ-ray energies Mev, 1.17 Mev and 1.17 Mev. It was found that there are deviation between theoretical values of mass attenuation coefficient (µ/ρ) and experimental values of mass attenuation coefficient where the theoretical values higher than experimental values. This is due to the presence of air voids in Portland cement samples without and with percentages of iron slag by weight. μ/ρ Mass attenuation coeffecient Mev Mev 1.17 Mev Mev 1.33 Mev + 5% slag + 15% slag Slag Percentage by weight + 25% slag + 35% slag + 45% slag Fig. 4 Effect of Slag Percentages by weight addition to cement on mass attenuation coeffecient at different gamma ray energies in Mev. Mass Attenuation Coeffecient μ/ρ exp. Mass atten. Coeff. At 0.511Mev Mev exp. Mass atten. Coeff. At 1.17 Mev 1.17 Mev exp. Mass atten. Coeff. At 1.33 Mev 1.33 Mev % slag + 15% slag + 25% slag + 35% slag + 45% slag Samples Fig. 5 Effect of slag percentages by weight addition to Portland cement on gamma ray mass attenuation coeffecient experimentally and theoretically.

5 842 Effect of Gamma Ray Energies and Addition of Iron Slag by weight to Portland s on Mass 4. Conclusions In this paper and based on the theoretical in addition to experimental values of total linear attenuation coefficient (µ) and also mass attenuation coefficient (µ/ρ), it is concluded that the former parameters increase with increasing the iron slag percentages addition to Portland cement by weight (5%, 15%, 25%, 35% and 45%). There are deviation between theoretical and experimental values of both linear and mass attenuation coefficient. These results may be useful when these samples are to be used in radiation shielding, application. Acknowledgments The authors wishes to express them deep gratitude to Dr. Osama Amine Desouky, Ass. Prof. of inorganic chemistry. Department of chemistry, faculty of science, Omar Al-Mukhtar University in Libya for providing the samples of cement. References [1] A.F. Profio, Radiation Shielding and Dosimetry, John Wily and Sons, Inc. New York, [2] B.T. Price, Radiation Shielding, Pergamon Press, London, New York, Paris, [3] N. Singh, Comparative study of lead borate and bismuthlead borate glass as gamma-radiation shielding materials, Nuclear Instruments and Methods in Physics Research B 225 (2004) [4] I.I. Bashter, Magnetite ores with steel or basalt for concrete radiation shielding, Jpn. J. Appl. Phys. 36 (1997) [5] A.S. Makarious, On the utilization of heavy concrete for radiation shielding, Ann. Nucl. Energy 23 (3) (1996) [6] I.I. Bashter, Investigation of hematite serpentine and ilmenite-lemonite concrete for reactor radiation shielding, Ann. Nucl. Energy 23 (1) (1996) [7] A.S. Makarious, Total and secondary gamma doses in hematite-lemonite concrete biological shields, Kernenegie 34 (6) (1991) [8] I.C.P. Salinas, Effective density and mass attenuation coefficient for building material in Brazil, Applied Radiation and Isotopes 64 (2006) [9] C.M. Lee, Cracking effect on gamma ray shielding performance in concrete, Nuclear Engineering 49 (2007) [10] M. Erdem, A novel shielding material prepared from solid wast containing lead for gamma ray, Radiation Physics and Chemistry 79 (2010) [11] D.R. Ochbelagh, Investigation of gamma-ray shielding properties of concrete containing different percentages of lead, Applied Radiation and Isotopes 70 (2012) [12] S.P. Shirmardi, Comparison of photon attenuation coefficients of various barite concrete and lead by MCNP code, XCOM and experimental data, Annals of Nuclear Energy 55 (2013) [13] M.J. Berger, S.H. Hubbell, Photon cross section on A personal computer, National Institute of Standards and Technology Gaithersburg, MD, USA, [14] H.A.E. Khatab, Study the effect of granulated slag of musrata on the properties of ordinary portland cement darna, MSc. Thesis, Omar Al-Mukhtar University, Libya, [15] J. Wood, Computational Methods in Reactor Shielding, Inc. New, [16] K. Sakr, Effect of high temperature or fire in heavy weight concrete properties, and Concrete Research 35 (2005)