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We investigate the geometric phase produced by nonadiabatic transition of spin states at corners of mesoscopic square circuit with tilted magnetic field at its edges. From the Schrodinger equation, the transitions of electron spin state at corners are described by the transfer matrices. The eigenenergies and eigenstates are obtained from the cyclic condition and the multiplying of the transfer matrices. We show that there exist persistent charge and spin currents in such a system due to the lift of degeneracy between the opposite moving directions in the presence of the tilted magnetic field. The dependences of eigenenergies, geometric phase, charge and spin persistent currents on the tilting angles of magnetic field are analysed.

Distribution of the parallel momentum of $^{28}$Si fragments from the breakup of 30.7 MeV/nucleon $^{29}$P has been measured on C targets. The distribution has the FWHM with the value of 110.5 $\pm$ 23.5 MeV/c which is consistent quantitatively with Galuber model calculation assuming by a valence proton in $^{29}$P. The density distribution is also predicted by Skyrme-Hartree-Fock calculation. Results show that there might exist the proton-skin structure in $^{29}$P., Comment: 4 pages, 4 figures

Measurements of the total reaction cross sections (sigma (R)) for some proton-rich nuclei (N = 11 - 15 isotones) on a carbon target at intermediate energies have been performed on the Radioactive Ion Beam Line of the Heavy Ion Research Facility in Lanzhou. A larger enhancement of sigma (R) for P-27 has been observed than for its neighbours. Evidence for a proton halo in P-27 has been revealed in the Glauber analysis of the total reaction cross sections in terms of the difference factor d.

The total reaction cross sections (TRCSs) of 29S+28Si have been measured at intermediate energies. An obvious enhancement in TRCS of 29S is observed as compared with its neighbouring nuclei. The TRCSs of 29S+28Si are calculated with the modified Glauber theory in the optical limit and few-body approaches. The different factor d as a possible measure of halo appearance is deduced from the experimental and theoretical data. It is well accepted that 27P is a proton halo nucleus. Although not as anomalous as 27P, the different factor d of 29S is obviously larger than that of its neighbouring isotones of N = 13. This result indicates that a moderate proton halo may exist in 29S nucleus. We calculate the total reaction cross sections for 29S with the modified Glauber theory as a function of incident energy and compare the results with those for 27Si which is a core nucleus of 29S. The measured TRCSs of 27Si+28Si can be described to be satisfactory by the modified Glauber theory of the optical limit approach. Although a diffused nuclear density distribution is used, the theories still inadequately predict the experimental TRCSs of 29S+28Si, which further indicates the possibility of proton halo in 29S.

Total reaction cross sections sigma (R) for some proton-rich isotones (N = 10) near Al-23 on a carbon target have been measured at intermediate energies in the experiment performed at the Radioactive Ion Beam Line of the Heavy Ion Research Facility in Lanzhou. The Z-dependence Of sigma (R) shows a remarkable enhancement for Al-23 relative to its neighbours. The difference factor d has been deduced from the measured sigma (R) by using the Glauber or Boltzmann-Uehling-Uhlenbeck models. From the above analysis, a possible one-proton halo structure is suggested for Al-23.

fragments produced in the reactions of 69 MeV/nucleon Ar-36 and 55 MeV/nucleon Ar-40 on a Be target have been measured experimentally. The isotopic distributions from fragmentation reaction for both projectiles are reproduced by using a modified statistical abrasion-ablation model. the isotopic distributions produced in Ar-36 and Ar-40 fragmentation. disappearance of the isospin effect in the fragmentation reaction. A strong isospin effect is exhibited in Experimental evidence is seen for the disappearance of the isospin effect in the fragmentation reaction.

Measurements of the total reaction cross section for C12-16, N14-17 and O16-18 on carbon target at intermediate energies were performed on RIBLL of HIRFL. A larger enhancement of sigma(n) for C-15 was observed than that for its neighbors. The analysis of these data indicates possible existence of an anomalous nuclear structure in C-15. A new quantity was suggested as the criterion to distinguish anomalous structure nuclei from normal nuclei.

Fragments produced in the reaction of 60MeV/n O-18 On Be have been measured experimentally. The isotopic distribution of fragmentation reaction is well reproduced by a modified statistical abrasion-ablation model. It is predicted that the isotopic distribution shifts toward the neutron rich side for neutron rich projectile, but this isospin effect decreases with the increase of the atomic number difference Z - Z(A) and disappears at last, where Z and Z(A) are atomic numbers of the isotopic distribution and the projectile respectively.

Correlation measurements of neutrons and fragments have been performed in a reaction of 33.4 MeV/u 17N on a 9Be target. Energy spectra of n and nitrogen fragments were obtained at different angles. Based on the nuclear diffraction dissociation model, the measured energy spectra and the neutron angular distributions were reproduced quite well assuming that 17N was composed of 16N and n or 15N and 2n interacting with the nonlocal separable potential. The satisfactory agreement between the theoretical calculations and the experimental data shows that the contribution of Coulomb dissociation is negligible in the reaction concerned.

The experimental measurement of the total interaction cross sections of N, C, B, and Be isotopes on C-12 target at medium energies is described. A new formula that gives a good description of the energy-range relationship of energetic ions over a wide energy range is presented. The energy calibration of detectors is made by a Monte Carlo simulation method based on this new formula.

The separation and identification of isotopes emitted from the projectile fragmentation reaction of 80 MeV/u 20Ne on 9Be target were carried out by using the radioactive ion beam line in Lanzhou (RIBLL). Many proton rich isotopes are obtained. Their intensity and purity fit the theoretical calculations. Good separation and identification abilities of RIBLL A/ΔA > 300 and Q/ΔQ > 150, are obtained.

The quasi-elastic scattering of a secondary 6He beam (25 MeV/n) on a 9Be target has been measured for the first time with the application of a sophisticated tracking detector system. The angular distribution is reported. A phenomenological optical potential is obtained by fitting the experimental data, which encourages more accurate experimental measurements.

We measured the total reaction cross sections of 12N in Si at 36.2 MeV/u using B.adioactive Ion Beam Line in Lanzhou (RIBLL) with a new method. The reaction target was installed at the intermediate focusing point T1 at RIBLL. This scheme allows us to identify particles before and after the reaction target unambiguously. The total reaction cross section (1760 ± 78 mb) of 12N in Si is obtained. Assuming that 12N consists of a core 11C plus one halo proton, the excitation function of N on the Si and C targets is calculated with the Glauber model and the Fermi–Fermi density distributions. It can fit the experimental data very well. A large diffusion of the protons density distribution supports the halo structure for 12N.