The main objective of this study was to investigate the correlation between the indoor and outdoor ambient dose equivalent rates measured by the ion chamber inside and around the historical sacral objects at a few locations in Bosnia and Herzegovina. The investigated objects made of the traditional building materials were built in the Late Medieval, Post Medieval, and Ottoman Period of Bosnia and Herzegovina history. The LUDLUM Model 9DP instrument based on a pressurized ion chamber was selected for natural low level radiation measurements since the ionisation chambers have higher sensitivities than the other types of detectors. The detection capability of the LUDLUM Model 9DP pressurized ion chamber was examined in the laboratory conditions with a source of low activity and under natural environmental radiation conditions by measuring the indoor and outdoor dose rates. A weak positive correlation was found between the ambient dose equivalent rates inside the historical sacral objects and the dose rates outside the objects. The average evaluated value of the indoor to outdoor dose rate ratio of 1.07 for the studied historic objects is less than that obtained for the contemporary building materials such as concrete. No study on the indoor to outdoor dose rate ratio in Bosnia and Herzegovina measured by the LUDLUM 9DP dose rate meter based on an ion chamber has been conducted yet. In addition to direct measurements, the first gamma spectrometric analysis of a few samples of building materials from the Late Medieval period in Bosna and Herzegovina was performed. The results of the gamma analysis revealed almost uniform distribution of primordial radionuclides in the investigated samples. It was demonstrated that such materials had the reduced content of radioactive isotopes compared to the contemporary building materials and therefore they could have potential advantages in specific applications related to the environmentally sustainable architecture.

In contrast to some traditional neutron detectors, liquid scintillators are suitable for measuring spontaneous fission produced on the nanosecond time-scales. The high multiplicity events in a short period of time are signatures for fissile materials. The neutron and gamma multiplicities have potential to enable extraction of the fissile material attributes. The simulations presented in this paper were done using the MCNPX–PoliMi radiation transport code based on the Monte Carlo method. It was demonstrated that the energy and time information depending on the number of neutrons and gamma-rays emitted in spontaneous fission events of 252Cf contribute additionally to characterize a fission source.

This paper deals with correlation analysis of gamma dose rate measured in the test field with the five distinctive soil samples from a few minefields in Federation of Bosnia and Herzegovina. The measurements of ambient dose equivalent rate, due to radionuclides present in each of the soil samples, were performed by the RADIAGEMTM 2000 portable survey meter, placed on the ground and 1m above the ground. The gamma spectrometric analysis of the same soil samples was carried out by GAMMA-RAD5 spectrometer. This study showed that there is a high correlation between the absorbed dose rate evaluated from soil radioactivity and the corresponding results obtained by the survey meter placed on the ground. Correlation analysis indicated that the survey meter, due to its narrow energy range, is not suitable for the examination of cosmic radiation contribution.

This paper deals with the improvements of the linear artificial neural network unfolding approach aimed at accurately determining the incident neutron spectrum. The effects of the transfer functions and pre-processing of the simulated pulse height distributions from liquid scintillation detectors on the artificial neural networks performance have been studied. A better energy resolution and higher reliability of the linear artificial neural network technique have been achieved after implementation of the results of this study. The optimized structure of the network was used to unfold both monoenergetic and continuous neutron energy spectra, such as the spectra of 252Cf and 241Am-Be sources, traditionally used in the nuclear safeguards experiments. We have demonstrated that the artificial neural network energy resolution of 0.1 MeV is comparable with the one obtained by the reference maximum likelihood expectation-maximization method which was implemented by using the one step late algorithm. Although the maximum likelihood algorithm provides the unfolded results of higher accuracy, especially for continuous neutron sources, the artificial neural network approach with the improved performances is more suitable for fast and robust determination of the neutron spectra with sufficient accuracy.