[en] The fission processes of ¹¹²Sn+¹¹²Sn and ¹¹⁶Sn+¹¹⁶Sn are simulated with the combination of the Langevin equation and the statistical decay model. The masses of two fission fragments are given by assuming the process of symmetric fission or asymmetric fission by Monte Carlo sampling with the Gaussian probability distribution. From the analysis of the isotopic/isotonic ratios of the fission fragments from both reactions, the isoscaling behavior has been observed and investigated in detail. Isoscaling parameters α and β are extracted as a function of the charge number and neutron number, respectively, in different widths of the sampling Gaussian probability distribution. It seems that α is sensitive to the width of fission probability distribution of the mass asymmetrical parameter, but β is not. Both α and β drop with increasing beam energy and reduced friction parameter

[en] The incident energy and isospin dependencies of total reaction cross sections σ_R have been researched by using the Boltzmann-Uehling-Uhlenbeck (BUU) model. When the width parameter of square-type or HO-type density distribution is obtained by fitting the σ_R at relativistic energies, the calculated result with BUU-model can reproduce the experimental data at intermediate energies better than that with Glauber-model of optical limit approximation. The systematical underestimation of σ_R at intermediate energy was removed out by BUU calculation framework. It is found that σ_R is sensitive to nuclear equation of state (EOS). It is also found that the difference factor (d) defined in text is sensitive to the nuclear structure such as neutron halo and neutron skin, etc

[en] The study of the fission delay in reaction of ⁸⁴Kr+²⁷Al at 10.6 Mev/u and the systematics of fission delay are described. Authors also discussed the possibility to study the GDR γ rays emitted from the super-heavy compound system on the basis of the strong increasing of the GDR γ rays duo to the fission delay. The calculation results of the GDR γ rays from the super-heavy compound system via microscopic semi-classical Vlasov equation and the experimental data analysis for searching the super-heavy compound system via GDR γ were given

[en] The RMF (Relativistic Mean Field) calculations are performed systematically for light isotopes (A<40) with NL-SH parameter set. The calculated binding energies and root mean square (rms) radii of light nuclei are discussed. On the basis of the theoretical calculations and the experimental data, we have suggested a group of phenomenological formulas for the neutron, proton and matter rms radii for nuclei with A<40, including the drip-line nuclei. In these formulas, the effects of binding energies, isospin and separation energies are considered. These formulas not only agree to the experimental data for stable nuclei well, but also reproduce the abnormal large radii of nuclei near the drip-line that the previous empirical models fail to reproduce them

[en] Hard photon emitted from energetic heavy ion collisions is of very interesting since it does not experience the late-stage nuclear interaction, therefore it is useful to explore the early-stage information of matter phase. In this work, we investigated the directed flow and elliptic flow for proton-neutron Bremsstrahlung hard photons in intermediate energy heavy-ion collisions. The positive directed flow and negative elliptic flow of directed photons are illustrated and they seem to be anti-correlated to the free proton's flow. Also we calculated the two-photon correlation functions from which the information of photon source was extracted, and while two-photon azimuthal correlations are presented as a good method to extract the elliptic flow parameter v₂ of direct hard photons. (author)

[en] The iso scaling properties of the primary and final products are studied via isospin dependent quantum molecular dynamics (IQMD) model and sequential decay model GEMINI respectively, the iso scaling parameter alpha and beta of both primary and final products keeps no significant change for the light fragments, but increases with the mass increasing of intermediate and heavy products. The iso scaling dynamical effect is exhibited by that alpha value decreases a little with the evolution time prolonging, and opposite trend for the heavy products. The iso scaling secondary decay effect is reflected in the increasing of the alpha value for the final products which have secondary decay process. Furthermore the density dependence of the symmetry energy has also been explored. Isospin effect of the statistical emission fragments from the equilibrated source is investigated in the frame of statistical binary decay implemented into Gemini code, iso scaling behavior is observed and the dependences of iso scaling parameters alpha and beta on emission fragment size, source size, source isospin asymmetry and excitation energies are studied. Results show that alpha and beta neither depends on light fragment size nor on source size. A good linear dependence of alpha and beta on the inverse of temperature T is manifested and the relationship of alpha=4C_sym*delta(Z/A)² and beta=4C_sym*delta(N/A)² from different isospin asymmetry sources are satisfied. The symmetry energy coefficient Csym extracted from simulation results is about 23 MeV which includes both the volume and surface term contributions, of which the surface effect seems to play a significant role in the symmetry energy. Projectile fragmentation products were measured from 50 MeV/u 36,40 Ar induced reactions on ⁶⁴Ni, the projectile fragment yields are measured and their yield ratios for different isotopes and isotones are calculated, iso scaling behavior are observed for the light and intermediate mass fragments. The experimental results are compared with the EPAX prediction, Statistical Abrasion-Ablasion model (SAA) calculation and Isospin dependent Quantum Molecular Dynamical (IQMD) simulations

[en] Anisotropic flows of light nuclear clusters and hard photons are studied by nucleonic transport models in intermediate energy heavy ion collisions. The transverse momentum and rapidity dependences of the directed flow (v_1) and elliptic flow (v_2) are studied for light nuclear clusters and their scaling behaviors are found. The ratio of v_4/v_2"2 of nuclear clusters show a constant value of 1/2. Proton-neutron Bremsstrahlung hard photon shows non-zero flows with the contrary sign of proton's flows. (author)

[en] The reaction cross section of ¹⁷C on a carbon target at 79 A MeV has been measured by the transmission method. The density distribution of ¹⁷C was deduced using the finite-range Glauber model (FRGM) combined with the interaction cross section of ¹⁷C at high energy. The existence of a tail in the density distribution of ¹⁷C is suggested to get a better understanding of both the low energy and high energy data. Under a core plus single-particle assumption, analysis shows a dominant d-wave of the valence neutron in ¹⁷C

[en] The correlation between neutron-to-proton yield ratio (R_n_p) and neutron skin thickness (δ_n_p) in neutron-rich projectile induced reactions is investigated within the framework of the isospin-Dependent Quantum Molecular Dynamics (IQMD) model, By adjusting the diffuseness parameter of neutron density in the Droplet model for the projectile, the relationship of the neutron skin thickness and the corresponding R_n_p in the collisions is obtained. We simulate the reaction between Ca or Ni isotope with "1"2C at 50 MeV/u, and the simulated data for Ca and Ni isotopes induced reactions show a good linear correlation between R_n_p and δ_n_p for neutron-rich projectile. It is suggested that R_n_p could be used as an experimental observable to extract the neutron skin thickness for neutron-rich nucleus. When the neutron skin thickness of one isotope is obtained, we can get some information on the EOS in different theoretical models such as Skyrme Hartree-Fock, relativistic mean-field and BUU model. From the isotope dependence of neutron skin thickness, a lot of information on the derivation of volume and surface symmetry energy, as well as nuclear incompressibility with respective to density can be extracted. This is very important to the study of the EOS of asymmetric nuclear matter. (authors)

[en] Experiments of ²³Al and ²²Mg radioactive beams bombarding a ¹²C target at an energy of 60 ~70 A MeV have been performed at the projectile fragment separator beamline (RIPS) in the RIKEN Ring Cyclotron Facility to study the two-proton emission from ²³Al and ²²Mg excited states, respectively. The trajectories of the decay products, namely ²¹Na + p + p from ²³Al and ²⁰Ne + p + p from ²²Mg, are clean identified. The relative momentum and opening angle between two protons in the rest frame of three body decay channels are obtained by relativistic-kinematics reconstruction. The results demonstrate that there are some di-proton emission components from ²He cluster for the excited ²³Al and ²²Mg. (author)