The new matrix method for deriving counting rate equations describing coincidence summing of gamma and X-rays for germanium spectrometers

The method for deriving counting rate equations in coincidence summing of gamma and X-rays that we have developed has made it much easier to obtain the results as well as the measurement process itself. This method allows us to determine the activity of a radioactive source directly without calibration of the detector and also to simultaneously to determine the efficiency of detection. We have successfully applied the method to the radionuclide with a simpler decay scheme such as 139Ce, 57Co, 133Ba. The application of this method to the 152Eu as a radionuclide with a much more complex decay scheme has also been equally successful. We are applying the method to 235U and 231Th and the preliminary results show that it is possible to apply this method to these radionuclides as well.IX International Conference on Radiation in Various Fields of Research : RAD 2021 : book of abstracts; June 14-18, 2021; Herceg Novi, Montenegr

Optimisation by mathematical modeling of physicochemical characteristics of concrete containers in radioactive waste management

A method for obtaining an optimal concrete container composition used for storing radioactive waste from nuclear power plants is developed. It is applied to the radionuclides 60Co, 137Cs, 85Sr, and 54Mn. A set of recipes for concrete composition leading to an optimal solution is given

Experimental Test of Exponential Decay of 198Au

The experimental test of the exponential decay of 198Au has been performed applying the Ge semiconductor spectrometer. The decay of 198Au nuclei was followed by the precise measurement of the decay constant over the time interval of 1.3 half-life in the time period from 0.02 to 25 half-lives after the irradiation. No deviations from the exponential law have been detected within the limits of the experimental error. The measured value of the 198Au half-life was in good agreement with the previously measured value

Application of the new matrix method to coincidence summing effects in gamma spectroscopy

A new method has been developed for deriving counting rate equations describing coincidence summing of gamma and X-rays for germanium spectrometers. The coincidence summing effects occur whenever two or more cascading photons are emitted from the same nucleus and detected within the resolving time of spectrometer. The application of analytical approaches to coincidence summing effects makes it possible to predict all summation peaks that occur in the spectrum. Our work includes solving the problems of coincidence summarizing by introducing the new method with simpler algebra. The new analytical approach that we have developed also allows us to determine the activity of radioactive sources directly without calibration of the detector, which is very important in metrology of radionuclides. Accordingly, based on the value of the peak area in the spectrum and knowledge of probability transitions between excited states of a nucleus, it is possible to determine the efficiency of detection. This method is successfully applied to the decay of radionuclides 139Ce, 57Co, 133Ba and 152Eu. Results, obtained using the proposed method, are achieved in a much clearer and simpler wayVIII International Conference on Radiation in Various Fields of Research : RAD 2020 : book of abstracts; Virtual Conferenc

Decomposition of multi-particle azimuthal correlations in Q-cumulant analysis*

he method of Q-cumulants is a powerful tool for studying the fine details of azimuthal anisotropies in high energy nuclear collisions. This paper presents a new method, based on mathematical induction, to evaluate the analytical form of high-order Q-cumulants. The capability of this method is demonstrated via a toy model that uses the elliptic power distribution to simulate the anisotropic emission of particles, quantified in terms of Fourier flow harmonics . The method can help in studying the large amount of event statistics that can be collected in the future and allow measurements of the very high central moments of the distribution. This can, in turn, facilitate progress in understanding the initial geometry, the input to the hydrodynamic calculations of medium expansion in high energy nuclear collisions, and the constraints on it

New method for determination of temperature in spallation reactions

We propose a new method for determination of temperature in spallation events. It is shown that temperature can be determined by applying the friction model of energy dissipation in participant-spectator model of a spallation process. First order estimate of temperature dependence of the participant zone on reaction Q-value is obtained from the Fermi gas model considerations. The heat diffusion process is also discussed

Higher-order moments of the elliptic flow distribution in PbPb collisions at √sNN = 5.02 TeV

The hydrodynamic flow-like behavior of charged hadrons in high-energy lead-lead collisions is studied through multiparticle correlations. The elliptic anisotropy values based on different orders of multiparticle cumulants, v 2{2k}, are measured up to the tenth order (k = 5) as functions of the collision centrality at a nucleon-nucleon center-of-mass energy of s NN $$\sqrt{s_{\textrm{NN}}}$$ = 5.02 TeV. The data were recorded by the CMS experiment at the LHC and correspond to an integrated luminosity of 0.607 nb −1. A hierarchy is observed between the coefficients, with v 2{2} > v 2{4} ≳ v 2{6} ≳ v 2{8} ≳ v 2{10}. Based on these results, centrality-dependent moments for the fluctuation-driven event-by-event v 2 distribution are determined, including the skewness, kurtosis and, for the first time, superskewness. Assuming a hydrodynamic expansion of the produced medium, these moments directly probe the initial-state geometry in high-energy nucleus-nucleus collisions

A Logical Analysis of the Two Widely Spread Misinterpretations of the Well Established Results of the Special Theory of Relativity

By a rigorous logical analysis we show that the Ehrenfest paradox related to the relativistically rotating disc is not a paradox of the Special Theory of Relativity as it is usually treated in the literature because, as we proved rigorously, it does not follow from the principles of the Special Theory of Relativity but — contrary to this — contradicts them. We also analyse the logical status of the widely spread statement “moving clocks go slow” within the framework of the Special Theory of Relativity. Using the methods of the symbolic logic we show that this statement with correct interpretation of the meaning of the notion that the clock goes slow is, strictly speaking, at least misleading. We discuss the obtained results

A Note on a Nonstandard Interpretation of the Special Theory of Relativity

In our recent paper [1] we have shown in detail that the Ehrenfest paradox is not a paradoxof the Special Theory of Relativity (STR). We also analysed the logical status of the widelyspread statement that “moving clocks go slow”. We underlined that very often these problemsare treated very dogmatically. On the example of Tyapkin’s works [2, 3] we describe theregretable influence of dogmatic approach in the interpretation of the STR on the criticalthinking and approac