Frank Laboratory of Neutron Physics

Department of Nuclear Physics

Leader – E.V. Lychagin

Date and Time: Wednesday, 20 December 2017, at 11:00 AM

Venue: Conference Hall, Frank Laboratory of Neutron Physics

Seminar topic: «Principles for creation of intensive antineutrino lithium source on the base of neutron activation and creation of transuraniums under extremal neutron fluxes»

Speaker: V.I. Lyashuk (INR of RAS)

Abstract:

The discussed items: 1) the basic requirements and proposed realizations for creation of intensive electron antineutrino source of MeV-energy range and 2) processes of transuranium isotopes creation under the condition if artificial explosive nucleosynthesis. The high neutron flux density are the common and necessary condition for realization of the considered phenomena. The base process for creation of intensive electron antineutrino source is the neutron activation of ⁷Li isotope and subsequent emitting (at β^– -decay of ⁸Li) of hard electron antineutrino of MeV-range and energy up to 13 MeV. Creation of such lithium source demands to provide with high isotope purity, effective lithium-containing substances, developmental work of geometries to ensure high yield of ⁸Li isotope. For neutron activation we have considered the variants for two main types of neutron sources – nuclear reactor and accelerator scheme plus neutron-producting target.
It was obtained and confirmed by calculations the principal possibility to decrease the count errors (in two and more times), coused by uncertainties of reactor antineutrino spectrum. To solve the error problem of reactor antineutrino spectrum we propose the scheme of the source with regulated spectrum. The proposed scheme for accelerator variant is the compact lithium antineutrino source with linear dimension about 1.2-1.3 m (that is important for short base oscillation experiments and it allows to reduce the high purity mass of ⁷Li up to 120-130 kg).
It were considered the creation of transuranium isotopes under conditions of artificial explosive nucleosynthesis. To describe yields of transuranium elements and to take into account the dynamics of the short time process (~10^-6 s) the adiabatic model was proposed. The comparison of model results with experimental data is presented. The odd-even effect is considered.. The next development is realized by two-group dynamical model taking into account the spectrum features.. Taking into consideration the features of the artificial explosive process the binary model was proposed and the possibility to enlarge the transuranium yields by admixture of start nuclides is analyzed too.