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The ¹³C(α, n)¹⁶O reaction is believed to be the main neutron source reaction for the s-process in asymptotic giant branch (AGB) stars. The astrophysical S-factors of this reaction have been determined based on an evaluation of the α spectroscopic factor of the 1/2⁺ subthreshold state in ¹⁷O (E_x = 6.356 MeV) by using the ¹³C(¹¹B, ⁷Li)¹⁷O α transfer reaction. Our result confirms that the 1/2⁺ subthreshold resonance is dominant for the ¹³C(α, n)¹⁶O reaction at low energies of astrophysical interest.

The latest progress made in the field of radioactive ion beam physics is outlined and the key problems still under investigation are indicated. The focal points are the limit of nuclear existence, shell evolution and new magic numbers, halo and cluster structures, new excitation modes, and strong coupling between reaction channels. This field is still at a starting phase and much more new outcomes are foreseen.

Angular distributions for the ⁷Li(⁶Li, ⁷Li)⁶Li elastic-transfer reaction have been measured with the Q3D magnetic spectrograph at the HI-13 tandem accelerator of Beijing, China. The neutron spectroscopic factors of ⁷Li are derived by comparing the calculated differential cross sections, which are obtained through the distorted-wave Born approximation (DWBA) calculation, to the experimental data. And these spectroscopic factors are then used to deduce the direct capture cross sections in ⁶Li(n, γ)⁷Li at energies of astrophysical relevance.

In the present research, we used the ¹⁷Ne beam at 30.8 MeV/u to bombard the 43 mg/cm²¹²C target and measured the angular correlations between the fragments and emitted proton. In the break-up reaction of ¹⁷Ne, one-proton knockout would result in an unstable nucleus ¹⁶F, which would further decay by the proton emission. The measured angular correlation between the ¹⁶F momentum and the relative momentum of its decay products was compared with theoretical calculations and indicated that the valence proton in ¹⁷Ne has the most probability to be situated in the s_1/2 orbital with a small admixture of the d_5/2 orbital. The present results suggest that ¹⁷Ne has a halo structure.

The experiments of two-alpha emission from ^17,18Ne excited levels were performed at the HIRFL-RIBLL facility of the Institute of Modern Physics, Lanzhou. The beams of ¹⁷Ne at the energy of 49.9 MeV/u and ¹⁸Ne at 51.8 MeV/u bombarded a ¹⁹⁷Au target to populate excited states of ^17,18Ne via Coulomb excitation. Complete kinematics measurements were achieved by the detectors of a silicon strip and CsI+PIN array. The experimental results combined with simple MC simulations show the characteristic of sequential two-alpha emission via ¹⁴O excited states for ¹⁸Ne. The results of two-alpha emission from ¹⁷Ne are preliminary and need further analyses.

In the framework of the relativistic mean field theory, the isovector scalar interaction is considered by exchanging δ meson to study the influence of δ meson on the cooling properties of neutron star matter. The calculation results show that with the inclusion of δ meson, the neutrino emissivity of the direct Urca processes increases, and thus enhances the cooling of neutron star matter. When strong proton superfluidity is considered, the theoretical cooling curves agree with the observed thermal radiation for isolated neutron stars.

We used the Cornwall, Jackiw and Tomboulis (CJT) resummation scheme to study nuclear matter. In the CJT formalism the meson propagators are treated as the bare propagators and the the higher order loop corrections of the thermodynamic potential are evaluated at the Hartree approximation, while the vacuum fluctuations are ignored. Under these treatments in the CJT formalism we derived exact mean-field theory (MFT) results for the nuclear matter. The results are thermodynamically consistent, and our study indicates that the MFT result is the lowest order resummation result in the CJT resummation scheme. The relation between CJT formalism and MFT is clearly presented through the calculations.

In this paper we study the system with three nucleons within a single-j shell, which can be described as the angular momentum coupling of a nucleon pair and the odd nucleon. The overlaps between these non-orthonormal states form a special matrix coincidental with the one obtained by Rowe and Rosensteel. They proposed a proposition related to the eigenvalue problems of that matrix and dimensions of the associated subspaces. We prove their proposition with the help of the symmetric properties of the six-j symbols. We also derive algebraic expressions for eigen energies as well as conditions for conservation of seniority through the decomposition of the angular momentum.

The multiplicity of fragments in Fermi energy heavy-ion collisions was experimentally extracted. Compared with the results of calculation using the antisymmetrized molecular dynamics (AMD) model which accounts for the primary fragments only, the results calculated using the AMD together with a statistical decay code GEMINI to account for the deexcitation of excited primary fragments are in better agreement with those extracted from the experiment. This observation indicates that the experimental multiplicity distribution may be significantly different from those of primary fragments.

The excitation function of quasi-elastic (QEL) scattering at a backward angle has been measured for ⁹Be+²⁰⁸Pb. The barrier distribution was extracted by means of the first derivative of the measured excitation function and calculated with the coupled-channel model. The present work shows that the experimental barrier distribution extracted from QEL scattering is shifted to the low energy side by 1.5 MeV as compared with the theoretical one. This energy discrepancy indicates that breakup is important in the colliding processes of the weakly bound nucleus system.

The excited states of the doubly-odd ¹²⁰I have been investigated via the ¹¹⁰Pd(¹⁴N, 4n) and the ¹¹⁴Cd(¹⁰B, 4n) reactions at beam energies of 64 MeV and 48 MeV, respectively. The previously known bands are extended, and a new band structure is established. The yrast band is assigned to the πh_11/2 ⊗ νh_11/2 configuration instead of the previously assigned πg_7/2 ⊗ νh_11/2 configuration. Possible configurations of the other observed bands are also discussed.

The cross sections of fragments (σ_f) produced in the even ^36∼52Ca projectile fragmentation reactions at 80 AMeV are calculated in the framework of the statistical abrasion-ablation model. The distributions of σ_f are investigated. Linear correlations between the peak positions of the distributions and charge numbers of the fragment isotopes are found.

High spin states in the odd-A nucleus ¹¹³In have been investigated using the reaction ¹¹⁰Pd(⁷Li, 4n) at a beam energy of 50 MeV. A new positive parity dipole band with the configuration of π(g_9/2)⁻¹ ⊗ ν(h_11/2)² ⊗ ν(g_7/2)² is established. The effective interaction V(θ) values of this band have been successfully described by a semiclassical geometric model based on shear mechanism, which show that the dipole band has the characteristics of magnetic rotation. In addition the collective rotational angular momentum for this band is extracted. The results show that the core contribution increases gradually with the increase of the rotation frequency.

In the framework of the single-particle potential model, the root-mean-square radii of s-wave valence proton distributions for P and S isotopes have been systematically calculated. The scaling law of s-wave valence proton distributions is obtained by analyzing the relation between radii and separation energies. Necessary condition for the occurrence of 2s_1/2-state proton halos is deduced from the scaling law. Quantitative condition derived from this work can to some extent serve as reference for proton halo search.

The g-factors of Ground Rotational Band states of N = 44 isotones ⁸²Sr, ⁸³Y, ⁸⁴Zr and ⁸⁵Nb have been measured by the transient-magnetic-field ion implantation perturbed angular distribution (TMF-IMPAD) method. The measured g-factors of ⁸²Sr increase with the increase of spin I, indicating a proton alignment only. Positive peaks appear in the variation of g-factors with spin for ⁸³Y and ⁸⁴Zr at spin 21/2⁺ and 10⁺ respectively, indicating a proton alignment followed by a neutron alignment. A negative peak occurs for ⁸⁵Nb at the spin 25/2⁺, indicating a neutron alignment followed by a proton alignment.

¹⁵²Dy is the first observed superdeformed nucleus, whose band structure reflects the typical distribution of high j low Ω orbitals of superdeformed nuclei in A∼150 mass region. The particle-number conserving treatment of the cranked shell model with monopole and quadrupole paring interactions is adopted to investigate the observed six superdeformed bands in ¹⁵²Dy. The π[523]7/2 orbital is emphasized for the first time to interpret the microscopic structure of band 2 and 3 of ¹⁵²Dy. A new comprehension is proposed on the basis of ever existing experimental and theoretical results, and the reliability is illustrated by several superdeformed bands of neighboring nuclei.

High spin states of the odd-odd nucleus ¹²²I have been investigated via the fusion-evaporation reaction ¹¹⁶Cd(¹¹B, 5n) at a beam energy of 68 MeV. The yrast band is extended up to I^π = (29⁺). The band termination at I^π = (22⁺) reported in previous studies is confirmed and interpreted as arising from a shape change from collective prolate to noncollective oblate according to Total-Routhian-Surface (TRS) calculations. In addition, the I^π=(29⁺) state is assigned to the [πh_11/2(πg_7/2)²]_23/2-⊗[(νh_11/2)³(νd_5/2)²]_35/2⁻ configuration corresponding to the full alignment of all valance nucleons outside the semi-closed shell.

An experiment for measuring the hyperon-related fission rate was carried out with the reaction ²⁰⁹Bi(e, e'K⁺)²⁰⁹_ΛPb at the Thomas Jefferson National Laboratory (Jlab). In the experiment, the performance of the fission fragment detector (FFD) was dramatically crashed by the background particles in comparison with that during the test without beam. The scattering of the high intensity (500 nA) primary electrons was the dominant cause. Using the GEANT4 toolkit, this report simulates the experimental situation of the target chamber in which the FFD was located. The simulation results indicate that the background particles were dominantly δ electrons, and protons and alpha particles were the important heavy background particles. The performance of the multi-wire proportional chambers (MWPCs) depends not only on the background-particle intensity but also the current density, which was also given by the simulation code. Furthermore, the measures to suppress the background particles were also investigated with the simulation code.

A novel method has been established to realize the experiment of electron scattering off short-lived nuclei. The method was based on the well known "ion trapping" phenomenon in electron storage rings. In the R&D experiments at Kyoto University, stable nucleus, ¹³³Cs, was employed as the target nucleus. The luminosity of scattering experiment was nearly 1026 cm⁻²s⁻¹ at electron beam current around 75 mA. The angular distribution of elastically scattered electrons from trapped Cs ions was measured and the result was well fitted by theoretical calculation. It was indicated that higher luminosity can be reached with larger electron beam current.

The Penning trap is one of the most important experimental devices in the field of nuclear physics, and measures atomic masses with the highest precision in the world. Many such devices are currently in operation, with more being designed and constructed. To start the experimental study of atomic masses with very high precision in China, the Lanzhou Penning Trap (LPT) is being constructed at the Institute of Modern Physics, Chinese Academy of Sciences. In this paper the progress and status of the LPT will be reported.

Heavy metals have seriously contaminated soil and water, and done harm to public health. Academician WANG Naiyan proposed that ion-implantation technique should be exploited for environmental bioremediation by mutating and breeding plants or microbes. By implanting N⁺ into Taikonglian No.1, we have selected and bred two lotus cultivars, Jingguang No.1 and Jingguang No.2. The present study aims at analyzing the feasibility that irradiation can be used for remediation of soil and water from heavy metals. Compared with parent Taikonglian No.1, the uptaking and accumulating ability of heavy metals in two mutated cultivars was obviously improved. So ion implantation technique can indeed be used in bioremediation of heavy metals in soil and water, but it is hard to select and breed a cultivar which can remedy the soil and water from all the heavy metals.

X-ray fluorescence (XRF) in combination with partial least-squares (PLS) regression was employed to analyze the ore slurry grade. Using the Monte Carlo simulation code PENELOPE, X-ray fluorescence spectra of ore samples were obtained. Good accuracy was achieved when this method was used to analyze elements with concentrations of several percent or above. It was demonstrated that the more the number of X-ray fluorescence spectra used to calibrate, the better the obtained accuracy. In this method detector resolution was found to have little or no effect on the results of quantitative analysis. The effect of the concentration of water was investigated as well, and it was found to have little influence on the results.

Coincidence Doppler broadening measurements of positron annihilation for multi-walled carbon nanotubes, double-walled carbon nanotubes, single-walled carbon nanotubes and graphite were performed. The ratio curves of the Doppler broadening for these samples to silicon were obtained. It is shown that there are distinct peaks at the position of 10×10⁻³m₀c for both carbon nanotubes and graphite, however the amplitudes of the peaks are not the same. We have the opinion that these peaks arise from the annihilation of positron with the 2s and 2p electron of carbon element.

Measurements were performed of K-shell ionization cross sections of Ti element by 10∼30 keV positron impact using the thick-target method. The effects of multiple scattering of incident positron and from bremsstrahlung photons and annihilation photons with the thick-target method are discussed with the Monte Carlo code PENELOPE. Meanwhile, the Monte Carlo method is also applied to determine the detection efficiencies of X- and γ-ray detectors. Our experimental K-shell ionization cross sections for Ti element are compared with the distorted-wave Born approximation (DWBA) theoretical predictions, and it is found that the agreement of the experimental data and theoretical values is good and this indicates that the experimental method adopted in this study is applicable.

Tritium (³H) in excess of the atmospheric values was found at volcanic Lakes Pavin (France), Laacher (Germany) and Nemrut (Turkey), as well as Kilauea Volcano at Hawaii (USA) and other volcanoes. Because ³H has a short half-life of 12.3 years, the tritium and the resulting ³He must have formed recently in the Earth. The result suggests that nuclear reactions may generate a significant amount of tritium in the interior of the Earth, although we have not yet learned what the reaction mechanism may be responsible. The nuclear reaction that can be responsible for tritium production in the Earth is probably a new research field in physics science. Nuclear reactions that generate tritium might be a source of "missing" energy (heat) in the interior of the Earth. Finding in-situ ³H in the mantle may exhibit an alternative explanation of ³He origin in the deep Earth.

The La-dopping effect on the piezoelectricity in the K_0.5Na_0.5NbO₃ (KNN) crystal with a tetragonal phase is investigated for the first time using the first-principle calculation based on density functional theory. The full potentiallinearized augumented plane wave plus local orbitals (APW-LO) method and the supercell method are used in the calculation for the KNN crystal with and without the La doping. The results show that the piezoelectricity originates from the strong hybridization between the Nb atom and the O atom, and the substitution of the K or Na atom by the La impurity atom introduces the anisotropic relaxation and enhances the piezoelectricity at first and then restrains the hybridization of the Nb-O atoms when the La doping content further increases.