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1
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Determination of the Tenth and Half Value Layer Thickness of Concretes with Different Densities

100%
Akkaş A.
Acta Physica Polonica A
|
2016
|
vol. 129
|
issue 4
770-772
EN
Half value layer (HVL) is the most frequently used quantitative factor for describing both the penetrating ability of specific radiations and the penetration through specific objects. The half value layers (HVL) and tenth value layers (TVL) are defined as the thickness of a shield or an absorber that reduces the radiation level by a factor of one-half and one tenth of the initial level, respectively. The concepts of HVL and TVL are widely used in shielding design. They are photon energy dependent, like the attenuation coefficient. HVL and TVL values provide useful information about the penetration of a specific radiation in a specific material. In this study, TVL and HVL thickness are calculated for concretes with different densities. For this purpose five types of concrete with different density ranges were selected, with densities between 600-1500 kg/m^{3}, called lightweight concrete, 1400-2000 kg/m^{3}, called semi lightweight concrete, 2000-2500 kg/m^{3} called ordinary concrete, 2500-3000 kg/m^{3}, semi heavyweight concrete and 3000-4000 kg/m^{3} called heavyweight concrete, respectively. For evaluated TVL and HVL thicknesses, the linear attenuation coefficients μ, were determined from measurements, using a collimated beam of gamma rays from a Cobalt-60 source.
2
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Prediction Primary Radiation Shielding Wall Thickness with Artificial Neural Networks

51%
Akkaş A., Başyiğit C., Necip Kurtarici M.
Acta Physica Polonica A
|
2013
|
vol. 123
|
issue 2
171-172
EN
In this study, wall thickness for using in primary radiation shielding was determined in different energy ranges using tenth value layer by artificial neural networks. Radiation energy values, tenth value layers and negative logarithm of transmission factor (n) were selected as input parameters and wall shielding thickness values selected as output parameters. Consequently, developed artificial neural networks model outputs were compared with experimental results and it was seen that the results were harmonious.
3
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Determination of Radiation Attenuation Coefficients of Concretes in Different Densities

51%
Akkurt İ., Günoğlu K., Başyiğit C., Akkaş A.
Acta Physica Polonica A
|
2013
|
vol. 123
|
issue 2
374-375
EN
The density of the concrete is important parameter for different properties. Using different types and rates of aggregates cause different densities of the concretes. Radiation shielding properties can be varied with the density and it is important to obtain optimum density for this purpose. In this study radiation attenuation coefficients were measured by comparison of five different densities of concrete that called lightweight, semi-lightweight, ordinary and semi-heavyweight and heavyweight. For this purpose concretes were produced with suitable aggregate in laboratory conditions and determined some physical and mechanical properties. The total linear attenuation coefficient measurements have been obtained by a collimated beam of gamma ray from sources ^{60}Co.
4
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Radiation Shielding Properties of Shotcrete

45%
Gunoglu K., Akkurt I., Basyigit C., Çakıroğlu M., Akkaş A.
Acta Physica Polonica A
|
2014
|
vol. 125
|
issue 2
299-300
EN
Shotcrete is a concrete spraying of concrete or mortar that may be accomplished through either a dry- or wet-mix process. It is made of normal weight aggregates which have a density of approximately 2323 kg/m^3. For the most part, shotcrete is used in underground excavations in rock and repair work in constructions. In this study, linear attenuation coefficient (μ, cm^{-1}) was measured for shotcrete produced with dry mix process. Measurements were carried out by gamma spectrometry containing NaI(Tl) detector and multichannel analyzer.
5
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Cement Paste as a Radiation Shielding Material

45%
Akkurt İ., Günoğlu K., Başyiğit C., Kılınçarslan Ş., Akkaş A.
Acta Physica Polonica A
|
2013
|
vol. 123
|
issue 2
341-342
EN
Cement, mainly, natural limestone and clay mixture after being heated at high temperature is obtained by milling and it is defined as a hydraulic binder material. Especially, cement is used in production concrete. The photon attenuation coefficient (μ, cm^{-1}) for cement paste has been measured using gamma spectrometer containing NaI(Tl) detector and MCA at 835, 1173, and 1332 keV. Cement paste was prepared with types of Portland cement which is CEM I 52,5 R- and CEN reference sand has been used according to TS EN 196-1 standard. The mass attenuation coefficients have been calculated at photon energies of 1 keV to 100 GeV using XCOM and the obtained results were compared with the measurements at 835, 1173, and 1332 keV.
6
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Determination of Some Heavyweight Aggregate Half Value Layer Thickness Used for Radiation Shielding

39%
Akkurt İ., Başyiğit C., Akkaş A., Kılınçarslan Ş., Mavi B., Günoğlu K.
Acta Physica Polonica A
|
2012
|
vol. 121
|
issue 1
138-140
EN
A radiation dose above the maximum permissible limit is very dangerous for human being. In radiation shielding, absorbent materials' properties must be well known. Heavyweight concrete is the most widely used in the world for this aim. The aggregate component of concrete plays an important role in improving concrete properties and this is effect of shielding properties of concrete. The thickness of any given material where 50% of the incident energy has been attenuated is known as the half-value layer. The half-value layer is expressed in units of distance (mm or cm). Like the attenuation coefficient, it is photon energy dependent. Increase of the penetrating energy of a stream of photons will result in an increase in a material's half-value layer. In this study, half-value layer thickness of concrete containing limonite, siderite and barite at different ratios was investigated; for this purpose measurements have been obtained by a collimated beam of gamma ray from sources ^{60}Co. The total linear attenuation coefficient (μ), half-value layer thickness is evaluated in this study.
7
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Radiation Shielding Effect of Boron Carbide Aluminum Metal Matrix Composite

39%
Akkaş A., Tugrul A., Addemir O., Marşoğlu M., Ağacan B., Büyük B.
Acta Physica Polonica A
|
2015
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vol. 127
|
issue 4
947-949
EN
Boralyn (Al/B₄C) composite material is produced chiefly of boron carbide and aluminum. Boron Carbide is an important material for the nuclear industry due to high neutron absorption cross-section. This composite is used as shielding materials to absorb neutrons in the nuclear reactors and control road materials. In this study we investigated Al/B₄C composites against gamma radiation. For that purpose, 5 wt.%, 10 wt.%, 15 wt.% and 20 wt.% reinforcement content were investigated. Cs-137 gamma radioisotope source which has 662 keV gamma energy photons were used. For each material, linear and mass attenuation coefficients were calculated. Theoretical mass attenuation coefficients were calculated from XCOM computer code. The theoretical results were compared with experimental results. The results were showed that increasing the amount of Boron Carbide compound content of boralyn composite material decrease the linear and mass attenuation coefficient of materials
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