28 research outputs found
Gamow-Teller strength distributions for double-beta-decaying nuclei within continuum-QRPA
A version of the pn-continuum-QRPA is outlined and applied to describe the
Gamow-Teller strength distributions for -decaying open-shell
nuclei. The calculation results obtained for the pairs of nuclei Cd-Sn
and Te-Xe are compared with available experimental data.Comment: 8 pages, 3 figures, To appear in the proceedings of "Nucleus-2007:
Fundamental problems of nuclear physics, atomic power engineering and nuclear
technologies" Voronezh, Russia, June 25-29, 200
Novel hydrodynamic cumulation mechanism caused by quantum shell effects
The computational and theoretical analysis carried out in this article
demonstrates the existence of a nontrivial mechanism for the compression of a
submicron-sized gas bubble formed by a gas of classical ions and a gas of
degenerate electrons. This mechanism fundamentally differs from conventional
compression mechanisms. It is shown that taking into account the quantum effect
of a large spatial scale in the distribution of electrons qualitatively changes
the character of cumulative processes. Because of a large-scale electric field
caused by quantum shell effects, the compression process is characterized by
the formation of multiple shock waves. The values of gas temperature and
pressure achieved during compression occur higher by two orders of magnitude as
compared with the classical adiabatic regime. The analysis is carried out
within the framework of the following model: the dynamics of the electron
subsystem is described by equations of a quantum electron fluid, while the
hydrodynamic approximation is adopted for the ionic subsystem. The large scale
effect is taken into account by means of effective external field acting on
electrons. The theoretical analysis carried out within this approach clarifies
the nature of the cumulative process in the system under consideration; some
quantitative characteristics obtained with numerical simulation are presented.
The possibility of experimental observation of this cumulative mechanism is
analyzed. It is suggested that the manifestation of the effect can be observed
during laser compression of a system of submicron targets by measuring the
neutron yield.Comment: 49 pages, pdf onl
Exchange effects in composite-particle interaction
Algebraic version of the orthogonality conditions model is developed by analogy with the algebraic version of the resonating group model. It is shown that all exchange terms excluding ones originated by the exchange kernel of the potential energy can be easily taken into account in the frame of the formalism of the version. The potential term as a whole is modelled phenomenologically. Both direct algebraic approach and the method basing on the solution of the integro-differential Schrödinger equation containing nonlocal terms related to the forbidden and the semi-forbidden states are proposed. This equation turns out to be preferable in studies of narrow resonances. It is demonstrated that decay width of a system into two-heavy-fragment channel is strongly affected by the nonlocal terms
On damping of the gamow-teller resonance in 118Sb
Section III. Theory of Atomic Nucleus and Fundamental InteractionsThis work is partially supported by RFBR (grant No. 12-02-01303-a)
The resonating group model description of the radiative capture reaction 3He(α,γ)7Be
Section IV. Nuclear Reactions Theor
Problems of experimental and theoretical studies of the Gamow-Teller giant resonance in
Properties of the Gamow-Teller giant resonance (GTGR) in 118Sb are described within the semi-microscopic approach based on the extended version of the "charge-exchange" continuum-quasiparticle-random-phase-approximation and phenomenological treatment of the spreading effect. The structure effect of the configuration splitting of this GTGR is confirmed. With taking this effect into account the experimental data on excitation of the GTGR in direct and resonance reactions are analyzed