H. Ogata

Gross structure of deeply bound hole states in odd tin isotopes observed with the (3He, α) reaction

Abstract A study of the ( 3 He, α) reaction at 110 and 120 MeV on even tin isotopes revealed the presence of a (1g) −1 bump at E X = 6.3–7.0 MeV with the same spectroscopic factor as for the known (1 g 9 2 ) −1 deeply bound hole state.

Elastic scattering of 119 MeV 3He particles and energy and mass-number dependence of optical potential parameters

Abstract The elastic scattering of 119 MeV 3 He particles by 12 C, 27 Al, 58,60,62,64 Ni, 59 Co, 90,92 Zr and 89 Y has been investigated over a wide angular range in order to study the mass-number dependence of the optical potential and odd-even differences in the elastic scattering. The elastic scattering cross sections have been analyzed in terms of the optimal model. The data, except for 12 C, 27 Al and 59 Co, were fitted with r R = 1.21 fm, a R = 0.76 fm and r I = 1.17 fm, fixed at the average values. The following formulae were obtained for the three remaining parameters by combining with the energy dependence of the parameters (90–120 MeV) obtained previously: V=111.4−0.173E+ Z A 1 3 +14.9 N−Z A ( MeV ) W D =24.8−0.028E ( MeV ) , a I =0.754+0.78 N−Z A ( fm ) The depths of the valleys of the angular distribution in the case of 59 Co (I = 7 2 ) are considerably shallower than those for Ni isotopes, while the depths in the case of 89 Y (I = 1 2 ) are nearly the same as those for Zr isotopes. Thus it may be concluded that the odd-even differences are attributed to the scattering from the quadrupole moment of the odd- A nucleus (if I > 1 2 ).

Elastic scattering of 90–120 MeV 3He particles and an unambiguous optical potential

Abstract The elastic scattering of 109.2 MeV 3 He particles by 40 Ca, 58 Ni, 90 Zr and 116 Sn has been investigated over a wide angular range. The elastic scattering cross sections have been analyzed in terms of the optical model. The data for each nucleus studied were sufficient to eliminate the discrete ambiguity in the strength of the optical potential; the unique potential which fits the data has a real well depth of about 100 MeV and a corresponding volume integral per nucleon pair of about 310 MeV · fm 3 . The elastic scattering of 3 He particles by 58 Ni has been further measured at bombarding energies of 89.3 and 118.5 MeV, and the incident-energy dependence of the optical potential of 3 He particles for 58 Ni was obtained.

Excitation of isovector states by the (7Li,7Be) reaction on 12C and 13C

Abstract Isovector states in 12B and 13B are studied by using the (7Li, 7Be) reaction at a projectile energy of 21 MeV/nucleon. Angular distributions are measured at forward scattering angles of θL ⩽ 10° and compared with one-step distorted-wave Born approximation (DWBA) calculations. The form factors are microscopically evaluated with effective nucleon-nucleon interactions and realistic transition densities. The DWBA calculations reproduce the observed cross sections with normalization factors near to unity. This suggests that the (7Li, 7Be) reaction at 21 MeV/nucleon proceeds mainly through the one-step direct reaction process. The excitation of the giant dipole resonance is confirmed at E x = 7.6 MeV in 12 B and at E x = 9.5 MeV in 13B, from which the isovector collective potential strength is obtained to be V1 ∼ 50 MeV. The isovector octupole strength is observed in three states in 12B, but it is not distinctly observed in 13B.

PIXE measurement applied to trace elemental analysis of human tissues

Abstract PIXE measurement was applied for trace elemental analyses of 40 autoptic human kidneys. To investigate the reproducibility of the PIXE data, 9 targets obtained from one human liver were examined. The targets were prepared by wet-digestion using nitric and sulfuric acid. Yttrium was used as an internal standard. The extracted elemental concentrations for K, Fe, Cu, Zn, and Cd were in reasonable agreement with those obtained by atomic absorption spectrometry (AAS) and flame photometry (FP). Various correlations among the elements K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Rb, and Cd were examined individually for the renal cortex and renal medulla.

Dominance of the direct reaction process in the 12C(7Li, 7Be)12B reaction at θL=0° and EL⩾21 MeVA

The 12C(7Li, 7Be)12B reaction is studied at projectile energies of 14, 21 and 26 MeV/A. Emitted 7Be particles are detected at θL∼0° with an energy resolution of about 200 keV which is enough to separate transitions leading to the first excited state of 7Be (7Be1) from ones leading to the ground state of 7Be(7Be0). At incident energies higher than 21 MeV/A, both zero-degree excitation functions for 7Be0 and 7Be1 are well predicted by microscopic distorted-wave Born approximation calculations, but at an incident energy of 14MeV/A there are large contributions from complex reaction processes other than the one-step process.

Light-particle emission in the reaction of 93Nb + 14N at 132, 159 and 208 MeV

Abstract Nonequilibrium light-particle emissions have been investigated in the reaction 93 Nb + 14 N at 132, 159 and 208 MeV by measuring inclusive differential cross sections of p, d, t, 3 He and α. The experimental data were analyzed in terms of three models: (i) an extended exciton model, (ii) a coalescence model, and (iii) a moving thermal source model. The angle-integrated energy spectra of the protons were well described by the extended exciton model in which projectile nucleons were assumed to be transferred to the target one by one, but those of composite particles were not. On the other hand, the composite particle spectra (except for α at forward angles) were successfully described by the coalescence model using spectra consistent with those for the protons. Extracted coalescence radii P 0 were about 140 MeV/ c for d and t, and about 220 MeV/ c for α. The light-particle spectra were also fitted by the moving-source model assuming isotropic emission from a source moving with approximately half of the beam velocity and with much higher temperature than that of the compound nucleus. Extracted temperatures followed the systematics of a recent compilation for the various reactions. A discussion of these analyses is given.

Spin-flip probability in heavy-ion inelastic scattering☆

Abstract The spin-flip probability S(θ) was observed in the reactions 12C(13C, 13C′)12C(2+1) and 12C(15N, 15N′)12C(2+1) at E( 13 C ) = 87 and E( 15 N ) = 94 MeV , respectively, by particle-gamma angular correlations, in which gamma rays emitted both in-plane and out-of-plane were detected. Distorted-wave Born-approximation (DWBA) calculations required a strength of 2–3 MeV for the spin-orbit interaction to reproduce the observed S(θ), which is significantly larger than that given by the folding-model description.

Elastic scattering of 3He particles at 450 MeV

Abstract Elastic scattering of 3 He particles from 12 C, 28 Si, 58 Ni, 90 Zr and 208 Pb was measured at an incident energy of 450 MeV. Data were analyzed in the framework of the optical model based upon the Woods-Saxon parametrization. The depth of the real potential was determined to be about 30 MeV, irrespective of the target nucleus. It was found that volume integrals per nucleon of the real potentials became close to that of the proton and those of the imaginary potentials were about one half of that of the proton. A new empirical formula is proposed regarding the volume integrals per nucleon of the imaginary potentials.

Production of a nuclear polarized 3He+ beam☆

Abstract A nuclear polarized 3 He + beam with a polarization of 0.014±0.004 was produced by a new technique based on spin and charge transfer collisions between a 20 keV 3 He 2+ ion and a sodium atom polarized by laser optical pumping. Beam foil spectroscopy was used for the detection of the 3 He + nuclear polarization.