Neutron has been one of the most interesting particle since its discovery. Being an uncharged particle it is more difficult to shield in comparison with the other radiation types. This may be due to the differences of its interaction with matter. The main interaction processes of neutron with a matter may be via (n,p) reaction and thus hydrogenous materials are generally preferred to shield neutron. In this study neutron shielding properties for HAP composites have been investigated. This is done using Phy-X/PSD software.

The present study aims to investigate the gamma photon-neutron attenuation parameters of the marble concrete such as the linear attenuation coefficient ( $\mu$), Mass Attenuation Coefficient (MAC), Half Value Layer (HVL), neutron removal cross-section (∑_R), and Exposure Buildup Factor (EBF) by MCNPX Monte Carlo code to examine the possibility of utilizing selected samples against gamma photon-neutron. The six types of marble concrete were exposed to different energies ranging from 511 to 1332 keV. The shielding effectiveness of the selected marble concrete was compared to each other and the obtained results show that the increment of the penetration depth causes an increase in the value of EBF and the sharp peak is monitored at 200 keV. The ∑_R (neutron removal cross-section) values were also reported for all types of marble concrete. The outcomes depict that ∑_R is strongly relevant to the weight fractions of light elements of the selected shielding materials. Furthermore, the variations of ${\sigma }_a$ (total atomic cross-section) were reviewed and discussed versus wide energy ranges. Findings in all sections confirmed that NM-15 has the best gamma photon shielding quality in comparison with the other types of marble concrete, while NM-0 and NM-15 show the highest neutron proficiency.

The significance and novelty of the present work are the preparation of the non-lead ceramic by the general formula of (1-x) K_0.5Na₀.₅NbO₃-xLa Mn_0.5Ni_0.5O₃ (KNN-LMN) with different x (0<x<0.295) (mol) to examine the shielding qualities of KNN-LMN non-lead ceramic via FLUKA code. The obtained results via FLUKA code are used as input data for training the Artificial Neural Network (ANN) algorithm and prediction. For this purpose, the radio isotopic ²⁵²Cf neutron source is simulated by the HI-PROBE, RADDECAY, and DCYSCORE cards employing the FLUKA code. As a result, the neutron-gamma photon shielding ability of the KNN-LMN lead free ceramics exposed to the ²⁵²Cf neutron source is estimated and predicted. Findings show that by increasing the concentration of the x in (1-x) K_0.5Na₀.₅NbO₃-xLa Mn_0.5Ni_0.5O₃ lead free ceramics results in an ascending trend in density. In addition, the increment of the x rate (x refers to the concentration of La Mn_0.5Ni_0.5O₃ in KNN-LMN non-lead ceramics) causes an increase in the value of the neutron attenuation parameter ( $\sum _{\mathrm{t}}$), and a strong relationship is monitored between $\sum _{\mathrm{t}}$ and density. Moreover, descending order of (HVL)_x=0.01>(HVL)_x=0.04>(HVL)_x=0.07> … >(HVL)_x=0.25 is reported for HVL values against gamma photon. From the attained results it can be concluded that increaisng the rate of x, results in the better shielding proficiency in terms of neutron and gamma photon for chosen KNN-LMN based lead free ceramics. GRAPHICAL ABSTRACT

Gamma ray is an energetic radiation type that can ionize and thus damage living cells as it slows down and transfers its energy to cells. Because of this harmful effect cell should be protected. Besides developing new alternative to lead and lead based materials, it should be interesting to obtain shielding properties of skin. This paper presents a results on the shielding properties of skin.