FLNR SCIENTIFIC AND TECHNICAL COUNCIL MEETINGS AND SCIENTIFIC SEMINARS|
20.12.2017 - FLNR Scientific Seminar "Study of exotic nuclei with Z<20 at DRIBS accelerator complex", 15-30, Flerov Lab Conference Hall
Speaker: A.S.Fomichev, (on Doctoral thesis)
This work covers the advancement of the experimental methods applied to the study of 6He, 6Li, 6Be, 17Ne, 26P, 26,27S exotic nuclei at DRIBS complex. New data on structure of studied nuclei and rare decay channels with particle emission from the ground and excited states were collected using these methods.
Implanting 26P and 27S neutron deficient isotopes into the optical time projection chamber gave the exact values of probabilities of beta-delayed emission of one, two and three protons.
In experimental search for 26S unknown isotope in 32S(50.3 MeV/A)+Be fragmentation reaction the half-life limit of T1/2 (26S) < 79 ns was determined. 26S decay energy values in one-proton and two-proton emissions were specified in this experiment.
Method of combined mass applied for the first time to the study of rare brunch of 2p-decay of 17Ne(3/2-) nuclei first excited state enabled to find record low Γ2p / Γγ < 1.6(3) x 10-4 probability ratio (factor 50 compared to previous data). This method may be good for the study of other isotopes in the vicinity of stability line.
Method of registration of α-p-p three charged particles in 6Be decay was suggested and realized. Population of isovector soft dipole mode of ET > 4 MeV excitation energy was discovered in 6Be spectre in 1H(6Li,6Be)n charge-exchange reaction.
Study of complete and incomplete fusion reactions for 6He(64 MeV) + 166Er and 6Li(58 MeV) + 165Ho systems showed how 6He (neutron halo nucleus) and 6Li (nucleus has α+d cluster structure) nuclei structures influence the fusion cross section around the reaction Coulomb barrier.
Experiments were performed at FLNR accelerator complex.
18.12.2017 - FLNR Scientific Seminar "Mechanism of atomic nuclei interaction - formation and decay of heavy and super heavy systems", 15-30, Flerov Lab Conference Hall
Speaker: A.V.Karpov, (on Doctoral thesis)
Main mechanisms of formation and decay of heavy and superheavy nuclei are analysed in this work. Dynamic model of nucleus-nucleus collisions was developed and used for study of multinucleon transfer reactions in heavy nuclei collisions. In particular the possibility of synthesis of neutron-excess nuclei in the vicinity of N=126 closed neutron shell was studied this way. Production cross sections of superheavy nuclei in low energy collisions of actinides are estimated.
Prospects of fusion reactions for synthesis of Z>118 SHE are based on counted lifetimes and decay modes of heavy and SH nuclei. Existence of the region of experiencing electron capture SHE is predicted. New way of advancing into the region of neutron-rich SH nuclei is suggested.
Fusion reactions at energies around the Coulomb barrier are analysed. Role and relation of nuclear system degrees of freedom effecting fusion are studied.
14.12.2017 - FLNR CAP Scientific Seminar "Osmotic effects in "track" nanopores", 15-00, Flerov Lab Conference Hall
Asymmetric track membranes with nanopores are of great interest for researchers nowadays in connection with the fundamental questions of nanosystems functioning as well as due to variety of their possible applications. Osmotic effects of asymmetric itching of heavy ion tracks in polymer film are considered in this report. It's shown that measuring of osmosis flux brings useful data for better understanding of nanopore evolution. A model of convection-diffusion transport for description of concentration profile of the active electrolyte (etchant) in a pore is suggested. Contrary to the received opinion that osmotic effects are typical only to semipermeable membranes the examples of pronounced osmotic effects in a channel of 30-60 nm in diameter are given. Some inaccuracy of terminology concerning osmosis are discussed.