S. L. Jin

ION-BEAM SYNTHESIS OF YTTRIUM SILICIDES IN (111)SI

Formation of yttrium silicides in 170 keV, 4 X 10(17)/cm(2) Y+-implanted (111) Si has been investigated by transmission electron microscopy, X-ray diffraction and Auger electron spectroscopy. A continuous buried YSi2 layer, about 35 nm in thickness, was found to form beneath a 30 nm thick polycrystalline layer. Preferential growth of YSi2 with [001] YSi2 parallel to [111]Si was found to be the dominant mode of YSi2 growth. A high density of twins and stacking faults was observed to distribute in the layer beneath the silicide layer. In samples annealed at 800 degrees C for 1 min, a continuous silicide layer, about 100 nm in thickness, was found to form at the surface of the samples. The YSi2 was found to agglomerate in samples annealed at 1000-1100 degrees C for 1 min. A high density of defects remained beneath the original silicide/Si interface. The silicide maintained the epitaxial relationships with respect to the substrate. No sign of vacancy ordering was detected from examination of diffraction patterns of all as-implanted and annealed samples.

7Be, 8B+208Pb Elastic Scattering at Above-Barrier Energies

Angular distributions for the elastic scattering of 7Be and 8B by an enriched 208Pb target were measured at the Radioactive Ion Beam Line at Lanzhou (RIBLL). The incident energies of the radioactive beams were about three times the respective Coulomb barriers. A suppressed Coulomb-nuclear Interference Peak (CNIP) is not observed for 8B, a pronounced proton halo nucleus. Optical model fits were performed using Woods-Saxon potentials and the total reaction cross sections deduced. The results are discussed.

Quasi-elastic scattering of 10,11C and 10B from a natPb target

Angular distributions of the differential cross sections for the quasi-elastic scattering from a Pb-nat target by C-10 at 226 and 256 MeV, by C-11 at 222 MeV and 226 MeV, and by B-10 at 173 MeV were measured at the Heavy Ion Research Facility in Lanzhou, Radioactive Ion Beam Line in Lanzhou (HIRFL-RIBLL). Contributions from the inelastic scattering channels to these data are found to be negligibly small with coupled-channel calculations within the angular range covered by this experiment. These data can be well reproduced by optical model calculations with systematic nucleus-nucleus potentials. The reduced total reaction cross sections were compared with other existing data

Mass Measurements of Proton‐rich Nuclides at the Cooler Storage Ring at IMP

Recent results and progress of mass measurements of proton‐rich nuclei using isochronous mass spectrometry (IMS) are reported. The nuclei under investigation were produced via fragmentation of relativistic energy heavy ions of 78Kr and 58Ni. After in‐flight separation by the fragment separator RIBLL‐2, the nuclei were injected and stored in the experimental storage ring CSRe, and their masses were determined from measurements of the revolution times. The impact of these measurements on the stellar nucleosynthesis in the rp‐process is discussed.

Investigation of the near-threshold cluster resonance in 14 C

An experiment for m p(14C},14C*→10Be+α)p inelastic excitation and decay was performed in inverse kinematics at a beam energy of 25.3 MeV/u. A series of 14C excited states, including a new one at 18.3(1) MeV, were observed which decay to various states of the final nucleus of 10Be. A specially designed telescope system, installed around zero degrees, played an essential role in detecting the resonant states near the α-separation threshold. A state at 14.1(1) MeV is clearly identified, being consistent with the predicted band-head of the molecular rotational band characterized by the π-bond linear chain configuration. Further clarification of the properties of this exotic state is suggested by using appropriate reaction tools.

Direct Breakup Rections Of 8B At Fermi Energy

The longitudinal momentum distributions of the core-like fragment 7Be from the breakup of 8B on 12C target have measured at the energy of 36MeV/u at the Radioactive Ion Beam Line in Lanzhou (RIBLL). In order to distinguish the stripping and diffraction mechanisms involving in breakup reaction of 8B, both fragments of 7Be and proton are measured coincidently. With this coincident measurement, the widths of longitudinal momentum distribution are deduced with the values of 124±17MeV and 92±7 MeV for stripping and diffraction mechanism respectively. It is found that the longitudinal momentum width of stripping component is larger than that of diffraction component, which is different from the breakup reaction at high energy as around GeV/u. The theoretical calculations are compared with these experimental results.

β -decay study of the Tz=−2 proton-rich nucleus Mg20

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beta-decay study of the T-z =-2 proton-rich nucleus Mg-20

beta

Correlation between quarter-point angle and nuclear radius

decay of the drip-line nucleus

Beta-decay study of

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