Abstract

Background. The important characteristic of radioactive decay is the half-life period. For various radioactive isotopes the half-life period can lie in very wide ranges - from nanoseconds to millions years. It is shown that the existing databases of such constants can lead to non-physical, in particular, negative values of the activities of genetically related nuclides of natural series.
Methods. The scheme of harmonization of the nuclear-physical constants of nuclides of natural series ²³²Th, ²³⁵U, and ²³⁸U is presented, using the method of standard sets of nuclides and the method of statistical modeling. A feature of the approach is the use at calculations of "long arithmetics» and the Monte-Carlo method, in a time interval [0, 10¹²] years. The most interesting for harmonization of nuclear constants is the interval [0, 1-2] years.
Results. It is shown that the solution of the system of differential equations of Bateman depends on all set of values of the decay constants λ_і, which significantly (in 10¹⁵ times) differ in magnitude. It explains why the results of numerical modelling of the activities of some nuclides of natural series show the presence of non-physical (negative) solutions, for example, in the vicinity of the start time of the time. Possibilities of the calculation technique are illustrated on an example of nuclides of the natural series ²³²Th. The first results of harmonization of nuclear-physical constants are obtained.
Conclusions. The created software in the form of the web application with modern web standards. The program gives functionality for tasks in view by representation 3D files

Keywords: a method of standard sets of nuclide, nuclear constants, non-physical solutions, long arithmetics, harmonization, calculation code WEB-design

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