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The isotopic cross sections of residual nuclei produced in fragmentation reactions of 18O projectiles impinging on a carbon target at energies near 260 MeV/nucleon were measured at the HIRFL facility in Lanzhou (China). A full identification of atomic and mass numbers of fragments was achieved from the determination of their magnetic rigidity, energy loss, and time of flight. The production cross sections for a dozen of nitrogen, carbon, and boron isotopes were determined with uncertainties below 30% for most of the cases. The obtained cross sections for N and B isotopes show a rather good agreement with previous experimental data obtained with different projectile energies. The cross sections for some C isotopes seem to exhibit a dependence on the projectile energy. A comparison of the data and several theoretical model calculations are presented.

The elemental fragmentation cross sections of boron fragments produced by stable and neutron-rich 12-16C beams with a carbon target were systematically measured at an incident beam energy of approximately 240 MeV/nucleon. The measured cross sections were found to increase as the projectile mass number increases. The observed feature is explained qualitatively based on the abrasion-ablation two-stage reaction model and is compared quantitatively with predictions from various reaction models, including empirical and statistical models. All models agree with the measured cross sections within a factor of 2.

High-spin states in 161Er have been studied experimentally using the 150Nd(16O, 5n) reaction at a beam energy of 86 MeV. The relatively enhanced E1 transitions between the 5/2+[642] and 3/2−[521] bands are observed in 161Er, and the B(E1) values are extracted experimentally. The systematics of the R(E1) values in the N = 93 isotones are presented. It is found that the strength of the E1 transitions obviously exhibits angular momentum dependence, and the occurrence of the relatively enhanced E1 transitions could be attributed to octupole softness.

High-spin states in 185Pt have been reinvestigated via the reaction 173Yb(16O, 4n) at a beam energy of 90 MeV. The previously known band based on the ν7/2−[503](f7/2) Nilsson orbital has been extended to higher spin states. Properties of the ν7/2−[503](f7/2) band have been discussed with an emphasis on the evolution of configuration while increasing the spin.

High-spin states in nucleus 139Pm have been studied using the reaction 116Cd(27Al, 4n)139Pm. Two dipole cascades have been found. Spin and parity assignments were based on the Directional Correlation of Oriented Nuclei (DCO) ratios and systematic behavior in neighboring odd-proton nuclei. The level structures of 139Pm are compared with those of the N = 78 isotone 141Eu in which two dipole bands have been confirmed as magnetic rotational bands. The close similarity between them suggests that the dipole bands in 139Pm may be magnetic rotational bands.

High-spin states of 165Er were studied using the 160Gd(9Be, 4n)reaction at beam energies of 42 and 45 MeV. The previously known bands based on the v5/2? [523] and v5/2+ [642] configurations have been extended to high-spin states. Electric-dipole transitions linking these two opposite parity bands were observed. Relatively large B(E1) values have been extracted experimentally and were attributed to octupole softness.

The phi-charmonium dissociation reactions in hadronic matter are studied. Unpolarised cross sections for 12 reactions are calculated in the Born approximation, in the quark-interchange mechanism and with a temperature-dependent quark potential. The potential leads to remarkable temperature dependence of the cross sections. With the cross sections and the phi distribution function we calculate the dissociation rates of the charmonia in the interactions with the phi meson in hadronic matter. The dependence of the rates on temperature and charmonium momentum is meaningful to the influence of phi mesons on charmonium suppression., 21 pages, 12 figures

The model of three-body Borromean halo nuclei breakup was described by using standard phase space distributions and the Monte Carlo simulation method was established to resolve the detection problem of two neutrons produced from breakup reaction on the neutron wall detector. For 6He case, overall resolution σEk for the Gaussian part of the detector response and the detection efficiency including solid angle acceptance with regard to the excitation energy Ek are obtained by the simulation of two neutrons from 6He breakup into the neutron wall. The effects of the algorithm on the angular and energy correlations of the fragments are briefly discussed.

A time-of-flight system with a plastic scintillator coupled to photomultipliers is developed for the external target facility (ETF). This system can satisfy the requirement of an ultrahigh vacuum (~10−9 mbar), a high counting rate (~106 particles per second) and a magnetic field environment. In the beam test experiment, a total time resolution of 580 ps FWHM was obtained for the whole system, and nuclei with a mass of up to 80 could be identified using this system.