ИСТИНА

We present a brief overview of the modern Total Level Densities (TLD) concept of exited nuclei. The connection between TLD and the time characteristics of the induced fission nuclear reactions is discussed. The results of a number of the experimental and theoretical studies of the decay time characteristics of the excited actinide nuclei are shown. Measurements of the fission time of excited nuclei was performed using an experimental method developed in the SINP MSU and based on the shadows effect. Applying the shadows effect, the time characteristics of nuclear reactions can be explored in the wide range from 10-14 to 10-19 s. Analysis of the data is made in the framework of the statistical theory of nuclear reactions using the model of two-humped fission barrier. The results of the analysis reveal some previously unknown information about the parameters of two-humped fission barriers, as well as on the energy dependence of the level density in the second potential well of the nuclei.