Delayed $^{160}$Tb radioactivity buildup due to $^{159}$Tb(n,$^2$n) nuclear reaction products transformation and subsequent fusion

This paper deals with the formation of a bound dineutron in the outgoing channel of the $^{159}$Tb(n,$^2$n)$^{158g}$Tb nuclear reaction followed by assumed transformations of this reaction products. Such nuclear processes were studied in details from the point of view of $^{160}$Tb / $^{160}$Dy / $^{160}$Ho radioactivity change in time. Based on some preliminary signs of fusion process between heavier nuclei ($^{158g}$Tb and/or $^{158g}$Gd) and the deuteron, that is a bound dineutron decay product, the mathematical model, including three systems of differential equations, was developed to describe experimental data. This development requires a reasonable estimate for the half-life of a bound dineutron, which was found to be equal 5,877 seconds as the greatest. We mathematically modeled the delayed in time experimentally observed buildup of 160Tb radioactivity with a maximum at about 495 days since a neutron irradiation completion of Tb sample, based on the similarity with the parent - daughter nuclei radioactivity decay and accumulation nuclear process.