Zhang Chun-Lei

Experimental Evidence of Two-Proton Emissions from 18Ne Excited State

Experiment 18Ne+ 197Au was performed in Heavy Ion Research Facility Radioactive Ion Beam Line at Lanzhou (RIBLL). The nuclear energy levels of 18Ne were built by complete kinematical reconstruction of the decay products and diproton decay were observed from 18Ne excited states. At 6.15 MeV, the experimental relative momentum and angular correlations of the emitted protons are given. The obvious enhancement at |qrel| = 23 MeV/c and θc.m. = 40° shows the experimental criterion of 2He cluster decay from 18Neq.

Quadrupole moment and a proton halo structure in 17F (Iπ = 5/2+)

The quadrupole moment of light nuclei 17F in the ground state (Iπ = 5/2+) is measured by the β–NMR method. The effective charge of the last proton in a d5/2 orbit for 17F is extracted from the measured quadrupole moment Q(17F) divided by the quadrupole moment Qsp calculated with a single particle model. A proton effective charge of eeffp = 1.12 ± 0.07e is obtained, which is in agreement with that given by a particle–vibration coupling model calculation within the experimental error. The present value of the proton effective charge is strong evidence for the existence of a proton skin in 17F (Iπ = 5/2+).

Enhanced Photovoltaic Properties of Gradient Doping Solar Cells

An optimum design of a-Si:H(n)/a-Si:H(i)/c-Si(p) heterojunction solar cell is realized with 24.27% conversion efficiency by gradient doping of the a-Si:H(n) layer. The photovoltaic properties are simulated by the AFORSHET software. Besides the additional electric field caused by the gradient doping, the enhanced and widen spectral response also improves the solar cell performance compared with the uniform-doping mode. The simulation shows that the gradient doping is efficient to improve the photovoltaic performance of the solar cells. The study is valuable for the solar cell design with excellent performances.

Optical Potential Parameters for Halo Nucleus System 6He+12C from Transfer Reaction 11B(7Li, 6He)12C

The optical potential parameters for the halo nucleus system 6He+12C are extracted from fits to the measured angular distributions of 11B(7Li, 6He)12C reaction at energies of 18.3 and 28.3MeV with distorted-wave Born approximation analysis. The characters of the obtained optical potential parameters are basically consistent with the results extracted from the fits to the elastic-scattering angular distributions in the literature.

Optical Potential Parameters of Weakly Bound Nuclear System 17F+13C

Elastic scattering angular distributions of the 14N+16O system and the angular distributions of transfer reaction 16O(14N,13 C)17 F at ELab = 76.2 MeV and 57MeV have been measured and calculated by means of the exact finite-range distorted-wave Born approximation with the PTOLEMY code. The optical potential parameters for the weakly bound nuclear system 17F+13 C have been deduced and applied to analyse the elastic scattering angular distributions of the similar systems 17F+12C and 17F+14N which are taken from literature. The result shows that the transfer reaction with stable projectile and target combination can be used as an alternative method to extract the optical potential parameters for the weakly bound nuclear system.

Calculation of Interaction Potentials between Spherical and Deformed Nuclei

The interaction potential for spherical-deformed reaction partners is calculated. The shape, separation and orientation dependence of the interaction potential and fusion cross section of the system 32S+154Sm are investigated within the double-folding model of the deformed nuclei. The effective nucleon-nucleon interaction is taken to be the M3Y-Reid potential. The density is considered for three terms of the expansion using the truncated multipole expansion method, which is a deformed Fermi shape with quadrupole and hexadecapole for the density distribution of 154Sm. It is found for the interaction potential that the height and the position of barrier strongly depend on the deformations, the orientation angle of the deformed nucleus, and hence produce great effects on fusion cross section. The integrated fusion cross section is in good agreement with the experimental data.

Unusual Threshold Anomaly in the 6Li+208Pb System

The angular distributions of elastic scattering for the 6Li +208Pb system have been measured at several energies around the Coulomb barrier. The parameters of optical potential are extracted by means of a phenomenological optical model analysis. It is found that the real and imaginal potentials show a pronounced energy dependence. The behaviour of the potential at the nearly especially sub-barrier energies in the 6Li+208Pb system is quite different from the results of some previous reports observed in other systems, such as 19F+208Pb and 16O+208Pb. This unusual threshold phenomenon indicates that breakup channel is strongly coupled with the elastic channel and has obvious effects on optical potential.

Surface Diffuseness Anomaly in 16O+208Pb Quasi-elastic Scattering at Backward Angle

The quasi-elastic scattering excitation function of the doubly magic 16O+208Pb system at a backward angle is measured at sub-barrier energies with high precision. The diffuseness parameters extracted from both the single-channel and the coupled-channels calculations give almost the same value a = 0.76 ± 0.04 fm. The results show that the coupling effect is negligible for the spherical system. The obtained value is smaller than the extracted value from the fusion excitation function, but larger than the value of a = 0.63 fm, which is from the systematic analysis of elastic scattering data.

Dynamical Structure of Nuclear Excitation in Continuum

Dynamical structures of collective excitation in continuum are studied by calculating the isoscalar and isovector strength as well as transition density of nuclei near the drip-line such as 28O and 34Ca. It is found that for some excited states in continuum the proton and neutron transition density calculated from isoscalar and isovector excitation at some given energies may be different, which will affect the calculation of the polarization for nuclei with N≠Z.