Bazı Yapı Malzemelerinin Radyasyon Tutuculuk Özellikleri

Yapı malzemeleri, iç yapı oluşumlarına göre kalsiyum, silisyum ve metalik esaslı inorganik malzemeler ile, karbon, hidrojen ve azot esaslı organik malzemeler olmak üzere iki sınıfta toplanabilir. Bu araştırmada; radyasyon zırhlanmasında yapı malzemelerinin özellikleri malzemeler ile olan etkileşiminin ifadesi olan radyasyon tutuculuk katsayısı (μ); cam, normal beton, baritli beton, düşük karbon çeliği, ahşap gibi yapı malzemeleri için 10keV ile 100 GeV geniş enerji aralığında hesaplandı. Hesaplanan μ değeri, yüksek ve düşük enerji bölgelerinde önemli değişimler gösterirken, orta enerji bölgelerinde ise aynı değişimi göstermedi. Anahtar Kelimeler: Yapı malzemeleri, Radyasyon, Radyasyon tutuculuğ

Prediction Primary Radiation Shielding Wall Thickness with Artificial Neural Networks

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

Determination of Radiation Attenuation Coefficients of Concretes in Different Densities

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

Cement Paste as a Radiation Shielding Material

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

Determination of Some Heavyweight Aggregate Half Value Layer Thickness Used for Radiation Shielding

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 $\text{}^{60}Co$. The total linear attenuation coefficient (μ), half-value layer thickness is evaluated in this study