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Landmines pose significant humanitarian and strategic challenges, threatening both civilian populations and military operations worldwide. This study presents a practical simulation method based on Rayleigh and Compton scattering ratios to determine the effective atomic number of low atomic number (low-Z) explosives used in landmines. Utilizing the Monte Carlo N-Particle (MCNP) simulation program, Rayleigh/Compton scattering ratios were obtained using a Ge(Li) detector at a scattering angle of 115° within a simulated geometry. The simulation results were found to be in good agreement with experimental data, confirming the reliability of the method. Pure elements with atomic numbers ranging from 3 to 20 and various explosives were irradiated with photons of 59.54 keV energy to obtain scattering spectra. The effective atomic numbers calculated using Rayleigh/Compton scattering ratios were compared with five different theoretical methods, yielding consistent results. These findings demonstrate that the proposed method can reliably determine the effective atomic number of low-Z elements and explosives containing these elements. Additionally, the study confirms that MCNP simulations can be effectively utilized in various fields such as defense industry, radiation safety, medical applications, and radiation dosimetry.HIGHLIGHTS The effective atomic numbers of explosives in nine different landmines were determined using the MCNP simulation and compared with conventional methods.The MCNP simulation method offers a more practical and reliable approach for determining the effective atomic numbers of explosives.The Rayleigh-to-Compton scattering ratio was shown to accurately determine the effective atomic numbers of low atomic number materials.This method has significant potential for application in the detection of landmine explosives, providing a more effective alternative to conventional approaches.The effective atomic numbers of explosives in nine different landmines were determined using the MCNP simulation and compared with conventional methods.The MCNP simulation method offers a more practical and reliable approach for determining the effective atomic numbers of explosives.The Rayleigh-to-Compton scattering ratio was shown to accurately determine the effective atomic numbers of low atomic number materials.This method has significant potential for application in the detection of landmine explosives, providing a more effective alternative to conventional approaches. [ABSTRACT FROM AUTHOR]

Dose-mean lineal energies were measured using the variance–covariance method and commercial ionisation chambers in a therapy level 60Co field at several different air pressures. The results confirmed the trend from previous studies and the experimental data was extended down to a simulated object diameter of 4.2 nm using a low-noise electrometer. The variance–covariance method was adapted to consecutive charge integrations from a single ionisation chamber and used to correct for signal variations due to pressure drifts in the ion chamber. Monte Carlo simulations using MCNP 6.2 were performed, and the results follow the trend of the experimental values in the nanometric region. • y ¯ D -values were measured down to object diameters of 4.2 nm in a 60Co beam. • The measurements were performed using commercial ionisation chambers. • The variance–covariance method was adapted to a single ionisation chamber. • Monte Carlo simulations using MCNP 6.2 were performed. • The results follow the trend from previous measurements. [ABSTRACT FROM AUTHOR]

In the present study, radiation shielding properties of two glassy composite materials that are widely used in electronics, photovoltaic applications, and sensor technology, were investigated in the photon energy range from 15 keV to 15 MeV. The materials chosen were (ITO)/V2O5/B2O3 and ZnO/V2O5/B2O3 including various concentrations of B2O3. Radiation interaction was simulated and shielding parameters calculated by means of the MCNP and BXCOM codes. More specifically, buildup factors, effective electron density ( N eff ) and effective atomic number ( Z eff ) were calculated with BXCOM, while mass attenuation coefficients ( μ / ρ ), half-value layer (HVL) and tenth-value layer (TVL) values were calculated with MCNP. The results were compared with those obtained with the WinXCOM code, for validation. Acceptable and preferable results were obtained for both composites as alternative to other glassy shielding materials. The composite including ITO showed better shielding properties than the composite including ZnO. In terms of radiation shielding, both composites turned out to be better than concrete and close to lead. [ABSTRACT FROM AUTHOR]

The MCNP 6.2 event-by-event transport of electrons has been used for the first time to simulate energy imparted in low-density objects corresponding to nanometric unit-density objects. It is shown that the isolated atom assumption and the use of an average excitation energy based on stopping power, significantly alters the value of energy imparted from excitations. This limits to some extent the use of MCNP 6.2 in micro- and nanodosimetric applications, at least when excitations play an important role. Simulated single-event distributions show pronounced and anomalous excitation peaks related to the atomic composition of the target volume. In the case of air the dominating peak is related to excitations in nitrogen, while for tissue-equivalent gas the two dominating peaks are related to excitations in hydrogen and carbon. The excitation peaks in a nanometric unit-density water volume are also shown to be shifted compared to simulations with Geant4-DNA that take molecular excitation levels into account. Despite these limitations in addition to large cross-section uncertainties at low energies, the MCNP 6.2 simulated dose-average lineal energies are shown to agree well with experimental values in 60Co and 137Cs gamma beams as well as a 100 kV P x-ray beam. Simulated and measured values for an air-filled ionisation chamber agree within 10% for object diameters from 136 μm down to 20 nm. For smaller objects the experimental values based on ionisations and a conventional W e -value are as expected significantly higher than the simulated values. Only a few percent of this difference is related directly to the excitation peaks in the MCNP 6.2 simulations. • MCNP event-by-event electron transport for energy imparted in low-density targets. • MCNP and Geant4-DNA comparison of energy imparted. • Consequences of isolated atom assumption and the use of average excitation energies. • MCNP simulated and experimental y D in agreement for object diameters down to 20 nm. [ABSTRACT FROM AUTHOR]

Monte Carlo simulation of the Rayleigh/Compton scattering method for effective atomic number determination with MCNP (version 6.2) was proposed. As known, effective atomic numbers can be used for evaluating shielding behavior, in non-destructive analysis and medical imaging, especially for binary compounds with high precision. Various methods for the determination of effective atomic number are present in the literature, and they depend on different mathematical manipulations. For the first time, a simulation method was developed for the determination of effective atomic numbers of some compounds. Rayleigh to Compton scattering intensity ratios (R/C) of seven different pure elements (from Indium to Gadolinium) were determined with simulations. A straight line equation is fitted using R/C scattering intensity ratios of these seven elements. R/C values of five different compounds were also simulated. Thus, effective atomic numbers of these compounds were determined using the equation. The results of the simulation were compared with available experimental and theoretical results. The studied simulation method showed acceptable agreement with ZXCOM calculation results and acceptable results with the experimental study. This method is suitable to be used for almost every material type and quite insensitive to experimental details, such as material phase, thickness, etc. The simulation results are really encouraging and can be used to guide various experiments. • Monte Carlo simulation method of Rayleigh/Compton scattering ratio for effective atomic number determination was proposed. • Seven different elements (from Indium to Gadolinium) were used as sample targets to measure the scattering spectra. • R/C and Z connection was revealed. • Effective atomic numbers of some compounds were determined with the simulation method. • Also, obtained results were compared with the experimental and theoretical results for verification. [ABSTRACT FROM AUTHOR]

Analytic and stochastic methods were proposed for the determination of gamma-ray radiation shielding properties of the glassy composites. Radiation shielding properties such as mass attenuation coefficients, effective atomic numbers, effective electron numbers, build-up factors (exposure build-up factors and energy absorption build-up factors) can be determined with these techniques. A versatile quaternary composite was studied with different mass ratios in order to optimize the gamma radiation attenuation. Exposure build-up factors (EBFs), energy absorption build-up factors (EABFs), effective atomic numbers (Z eff) and effective electron densities (N eff) were calculated via BXCOM. Furthermore, MCNP transport code, version of 6.2, was used to simulate the mass attenuation coefficients (μ/ρ) and the half-value layers (HVLs) of the composites. Since they are compatible, simulation and BXCOM results denote that these methods can be used to determine the radiation shielding parameters for the glassy composites for which there are no satisfactory experimental values available. All in all, the optimum mass ratio, having the highest radiation attenuation, was determined as [Na 2 Si 3 O 7 /Bi 2 O 3 (65/35)/B 2 O 3 (2)/Sb 2 O 3 (11)], so that glassy composite might be preferred as a radiation shield in various applications. The quaternary glassy composites investigated in this study, performs better than ordinary concrete, getting close to pure lead as a radiation shield. • Main goal was to investigate radiation shielding properties of Na 2 Si 3 O 7 /Bi 2 O 3 /B 2 O 3 /Sb 2 O 3 quaternary glassy composites. • Determinations of mass attenuation coefficients and HVLs were carried out with MCNP 6.2 • Calculations of buildup factors, effective electron numbers and effective atomic numbers were performed with BXCOM. • Radiation shielding properties of quaternary composites were found better than concrete and approaching to lead. [ABSTRACT FROM AUTHOR]

New research on composite materials was proposed for both gamma ray shielding and fireproofing. When compared to concrete, composite materials show up higher shielding properties in the 0.015 MeV–15 MeV incident energy range. The composite was prepared with vanadium slag, epoxy resin and antimony-trioxide. Different ratios of ternary composite were investigated in order to determine the optimum ratio for shielding and anti-flame properties. Photon atomic parameters with shielding were determined by BXCOM and MCNP 6.2. BXCOM program determines the buildup factors (both EBF and EABF) in the 0.015–15 MeV energy range for up to 40 mean free path (mfp) penetration depth. It uses geometric progression (G-P) fitting method. The effective electron number ( N e f f ) and the effective atomic number ( Z e f f ) were also obtained with the BXCOM software. Furthermore, parameters such as the mass attenuation coefficients ( μ ρ ) , half-value layer (HVL) and tenth-value layer (TVL) were determined by MCNP 6.2 in order to confirm and compare with WinXCOM results. Obtained results may be concluded to have preferable shielding properties for the composite as an alternative to concrete. Antimony-trioxide (x=0.03), was found to exhibit the minimum EBF and EABF values, and is a convenient radiation shielding material. The Epoxy resin-vanadium slag and antimony-trioxide ternary glassy composite indicates better radiation shielding properties than concrete, but weaker than lead. • Shielding composite is made from vanadium, epoxy resin and antimony. • Mass attenuation of the composite is increasing with higher Sb 2 O 3 concentration. • Radiation shielding properties of composite were found between concrete and lead. • Composite can be used as injecting mortar for cracks developed in concrete shields. [ABSTRACT FROM AUTHOR]