0000000000480351
AUTHOR
G. G. Chubarian
Fusion-fission and quasifission of superheavy systems withZ=110–116formed inCa48-induced reactions
Background: In heavy-ion-induced reactions the mechanism leading to the formation of the compound nucleus and the role of quasifission is still not clear.Purpose: Investigation of the quasifission process of superheavy composite systems with $Z=110\text{\ensuremath{-}}116$ and comparison with properties of fusion-fission and quasifission of lighter composite systems.Method: Mass and energy distributions of fissionlike fragments formed in the reactions $^{48}\mathrm{Ca}+^{232}\mathrm{Th}$, ${}^{238}\mathrm{U}$, ${}^{244}\mathrm{Pu}$, and ${}^{248}\mathrm{Cm}$ at energies near the Coulomb barrier have been measured using the double-arm time-of-flight spectrometer CORSET at the U-400 cyclotron…
Structure of exotic 7He and 9He
The heavy helium isotopes 7,9 He were studied via their isobaric analog states (IAS) in 7,9 Li. The IAS were populated via resonance reactions of protons with radioactive beams of 6,8 He. The isospin-conserving neutron decay of T=3/2 resonances in 7 Li and proton decay of T=5/2 resonances in 9 Li were measured. New spectroscopic information on these states were obtained, and compared with the properties of levels in 7,9 He.
T=5/2states in9Li:Isobaric analog states of9He
The thick target inverse kinematic method was applied to the study of isobaric analog states in the neutron-rich nucleus ${}^{9}\mathrm{Li}.$ For this purpose, an excitation function for ${}^{8}\mathrm{He}+p$ elastic scattering was measured in the center-of-momentum energy range from 1.6 to 5.8 MeV. Three $T=5/2$ states in ${}^{9}\mathrm{Li}$ (isobaric analogs of ${}^{9}\mathrm{He})$ were observed. Restrictions on the spin-parity assignments are provided according to R-matrix calculations, and conclusions regarding the structure of ${}^{9}\mathrm{He}$ are given.
The study of neutron-rich nuclei production in the region of the closed shell N=126 in the multi-nucleon transfer reaction 136Xe+208Pb
Expérience LNL/PRISMA; International audience; The unexplored area of heavy neutron rich nuclei is extremely important for nuclearastrophysics investigations and, in particular, for the understanding of the r-process ofastrophysical nucleogenesis. For the production of heavy neutron rich nuclei located along theneutron closed shell N=126 (probably the last "waiting point" in the r-process of nucleosynthesis)the low-energy multi-nucleon transfer reaction 136Xe+208Pb at Elab=870MeV was explored.Due to the stabilizing eect of the closed neutron shells in both nuclei, N=82 and N=126, andthe rather favorable proton transfer from lead to xenon, the light fragments formed in this processare well b…
Neutron and gamma-ray emission in the proton induced fission of 238U and 242Pu
Abstract Average prescission Mpren and postscission Mpostn neutron multiplicities as well as average γ-ray multiplicity 〈Mγ〉, average energy 〈Eγ〉 emitted by γ-rays as a function of mass and total kinetic energy (TKE) of fission fragments were measured in proton induced reactions p+ 242 Pu→ 243 Am , p+ 238 U→ 239 Np at proton energy Ep=13, 20 and 55 MeV.
The fusion-fission process in the reaction 34S+186W near the interaction barrier
International audience; The reaction 34S + 186W at Elab=160 MeV was investigated with the aim of diving into the features of thefusion-fission process. Gamma rays in coincidence with binary reaction fragments were measured using the high efficiencygamma-ray spectrometer ORGAM at the TANDEM Accelerator facility of I.P.N., Orsay, and the time-of-flight spectrometerfor fission fragments (FF) registration CORSET of the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna. The couplingof the ORGAM and CORSET setups offers the unique opportunity of extracting details for characterizing the fusion-fissionprocess and gives information regarding production of neutron-rich heavy nuclei. The FF-$\gamm…
Isobaric analog states as a tool for spectroscopy of exotic nuclei
Abstract Spectroscopy of neutron rich exotic isotopes via their isobaric analog states (IAS) in less exotic nuclei is discussed. Several different experimental techniques, which can be applied to search for IAS of exotic isotopes, are described. Successful application of these techniques to the studies of heavy helium isotopes 7 He and 9 He led to the observation of unknown IAS in 7 Li and 9 Li. Spectroscopic information for these states were obtained, and implication of these findings to the structure of 7,9 He is considered.
Study of a-cluster states of 22Mg from resonance scattering of a post-accelerated 18Ne radioactive ion beam
An experiment aimed at the study of the α-cluster structure of 22Mg was performed at the Louvain la Neuve RIB facility. Preliminary results from a first feasibility run will be presented.