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To fabricate sandwich-structure composite of porous metal with nonporous surface layer, the nonporous skin layer was formed on surface of open-cell type nickel foam from aluminum powder by friction stir powder incremental forming (FSPIF) process. In this process, the surface pores of the foam were filled with the powder, then the powder and the cellular matrix near the surface of the foam were incrementally hammered by a rod-shaped tool without rotation. After that, the hammered surface of the foam was incrementally stirred by the tool at a very high rotation rate. The formed skin layer was composed of two layers; the friction stirred layer (relative density: above 0.90) in the upper part and the compact layer (relative density: 0.60–0.90) in the lower part. The friction stirred layer with a maximum thickness of 0.8 mm was formed on the surface of the foam without deforming the cellular matrix of the inside of the foam under the forming conditions; a tool rotation rate of 8000 rpm, a tool feed rate of 60 mm/min, a tool pushing pitch of 0.1 mm, and a total forming depth of 5.0 mm.

We have measured the differential cross-sections and analyzing powers for ($p,2p$) reactions at an incident energy of 392 MeV on $^{12}$C, $^{16}$O, $^{40}$Ca, and $^{208}$Pb nuclei, leading to discrete states of the residual nuclei. The data are compared with two kinds of distorted-wave impulse approximation (DWIA) calculations, a standard calculation using a global optical potential and a calculation using wave functions generated in a relativistic Hartree model. The spectroscopic factors deduced from these two calculations agree with those determined in ($e,e'p$) studies mostly within 15% in the case of the lighter three target nuclei. However, those for the $^{208}$Pb target are overestimated compared with the ($e,e'p$) results. In the heavy target case, the DWIA results are very sensitive to the radius parameter of the bound-state potential and thus a careful treatment is required. Regarding the analyzing powers of the present measurement, we confirmed that the $j$-dependence is sufficient for practical spectroscopic use.

Progress in proton elastic scattering at intermediate energies to determine nuclear density distributions is reviewed. After challenges of about 15 years to explain proton elastic scattering and associated polarization phenomena at intermediate energies, we have reached to some conclusions regarding proton elastic scattering as a means of obtaining nuclear densities. During this same period, physics of unstable nuclei has become of interest, and the density distributions of protons and neutrons play more important roles in unstable nuclei, since the differences in proton and neutron numbers and densities are expected to be significant. As such, proton elastic scattering experiments at intermediate energies using the inverse kinematic method have started to determine density distributions of unstable nuclei. In the region of unstable nuclei, we are confronted with a new problem when attempting to find proton and neutron densities separately from elastic proton scattering data, since electron scattering data for unstable nuclei are not presently available. We introduce a new means of determining proton and neutron densities separately by double-energy proton elastic scattering at intermediate energies.

A new type of neutron detector, named Stack Structure Solid organic Scintillator (S 4 ), consisting of multi-layer plastic scintillators with capability to suppress low-energy γ rays under high-counting rate has been constructed and tested. To achieve n - γ discrimination, we exploit the difference in the ranges of the secondary charged particles produced by the interactions of neutrons and γ rays in the scintillator material. The thickness of a plastic scintillator layer was determined based on the results of Monte Carlo simulations using the Geant4 toolkit. With layer thicknesses of 5 mm, we have achieved a good separation between neutrons and γ rays at 5 MeV ee threshold setting. We have also determined the detection efficiencies using monoenergetic neutrons at two energies produced by the d + d → n + 3 He reaction. The results agree well with the Geant4 simulations implementing the Li e ge Intranuclear Cascade hadronic model (INCL++) and the high-precision model of low-energy neutron interactions (NeutronHP).

The isospin character of p-n pairs at large relative momentum has been observed for the first time in the ^{16}O ground state. A strong population of the J,T=1,0 state and a very weak population of the J,T=0,1 state were observed in the neutron pickup domain of ^{16}O(p,pd) at 392 MeV. This strong isospin dependence at large momentum transfer is not reproduced by the distorted-wave impulse approximation calculations with known spectroscopic amplitudes. The results indicate the presence of high-momentum protons and neutrons induced by the tensor interactions in the ground state of ^{16}O.

The angular distribution of 12 C + 12 C scattering at an incident energy of 100 A MeV has been measured. The elastic and inelastic scatterings in 12 C to the excitation energies of up to ∼ 45 MeV were measured simultaneously for the first time with the high-resolution Grand Raiden spectrometer at the Research Center for Nuclear Physics (RCNP). The angular distributions of the elastic scattering to the ground state ( 0 1 + ) and inelastic scattering to the 4.44 MeV ( 2 1 + ) excited state were precisely obtained in the angular range of 1.0°–7.5° with a step of 0.1°. Additionally, the angular distribution was obtained for the sum of the cross sections for excitation energies above the 4.44 MeV state up to 11 MeV, which includes the 7.65 MeV ( 0 2 + ), 9.64 MeV ( 3 1 − ), and 10.30 MeV ( 2 2 + ) states, in addition to probably the simultaneous excitation of the 4.44 MeV state in the projectile and the target nuclei. Those combined data provide a means to study the effects of channel coupling on the elastic cross section. The observed angular distributions are compared with theoretical calculations based on three double-folding models with complex G-matrix interactions, the CEG07b, MPa, and ESC models. The importance of three-body repulsive forces included in the CEG07b and MPa models will be discussed.

Friction stir incremental forming (FSIF) process was applied to join a commercial open-cell type nickel foam with a polymethyl methacrylate (PMMA) sheet for fabrication of porous metal–nonporous resin composite. In this process, a rotating rod-shaped tool was vertically pushed and horizontally fed against the sheet on the foam. The sheet was frictionally heated and incrementally deformed by the rotating tool, while the cellular matrix of the foam was not plastically deformed. The sheet with a thickness of 1.0 mm was joined with the foam under FSIF conditions of rotation rate faster than 2000 rpm and feed rate slower than 60 mm/min. The joining strength between the foam and the sheet was investigated by performing tensile test. The joining strength was obtained over the fracture strength of the foam. The joining mechanism of the foam and the sheet was discussed from the microscopic observation of the foam–sheet interface and the temperature change in the sheet. It is concluded that the sheet was mechanically interlocked (anchored) to the porous structure of the foam by the plastic flow of the heated and softened PMMA into the surface pores of the foam.

The nuclear shell structure, which originates in the nearly independent motion of nucleons in an average potential, provides an important guide for our understanding of nuclear structure and the underlying nuclear forces. Its most remarkable fingerprint is the existence of the so-called magic numbers of protons and neutrons associated with extra stability. Although the introduction of a phenomenological spin–orbit (SO) coupling force in 1949 helped in explaining the magic numbers, its origins are still open questions. Here, we present experimental evidence for the smallest SO-originated magic number (subshell closure) at the proton number six in 13–20C obtained from systematic analysis of point-proton distribution radii, electromagnetic transition rates and atomic masses of light nuclei. Performing ab initio calculations on 14,15C, we show that the observed proton distribution radii and subshell closure can be explained by the state-of-the-art nuclear theory with chiral nucleon–nucleon and three-nucleon forces, which are rooted in the quantum chromodynamics., Magic numbers are associated with the stability of atomic nuclei. Here, the authors analyse the proton radii, binding energies and electric quadrupole transition rates of neutron-rich carbon isotopes at proton number six and use nuclear structure models to support the magic number Z = 6.

The isoscalar giant monopole resonance (ISGMR) strength distribution in $^{24}$Mg has been determined from background-free inelastic scattering of 386-MeV $\alpha$ particles at extreme forward angles, including 0$^{\circ}$. The ISGMR strength distribution has been observed for the first time to have a two-peak structure in a light-mass nucleus. This splitting of ISGMR strength is explained well by microscopic theory in terms of the prolate deformation of the ground state of $^{24}$Mg., Comment: 5 pages, 4 figures; to be published in Phys. Lett. B

By using para-hydrogen and a mechanical press made of neodymium magnets, we have succeeded in making a 1-mm-thick and 30-mm-diameter solid hydrogen target (SHT), and have measured elastic scattering of protons with radioactive ion beams at 300 MeV/u. We also succeeded in making not only a 0.5-mm-thick and 10-mm-diameter SHT but also a 2-mm-thick and 30-mm-diameter SHT to study excited-state properties of nuclei via (p,p′) reactions, and quasi-free (p,pα) reactions at intermediate energies. The ortho–para converter and the simple mechanical press show possibilities for making SHTs which have various radii and thicknesses.

The angular distributions of differential cross sections of $^{12}\mathrm{C}+^{12}\mathrm{C}$ elastic and inelastic scattering populating the ground and excited states in $^{12}\mathrm{C}$ up to 15 MeV excitation energy are precisely measured for the first time at an incident energy of $100A$ MeV to study the effect of repulsive three-body forces. Using the high-resolution spectrometer Grand Raiden at the Research Center for Nuclear Physics (RCNP), Osaka University, we have obtained the differential cross sections for the ground state (${0}_{1}^{+}$) and 4.44 MeV (${2}_{1}^{+}$) excited state, as well as the summed differential cross sections for the states between 4.44 and 15 MeV in the angular range of $1.{0}^{\ensuremath{\circ}}--7.{5}^{\ensuremath{\circ}}$. The results are compared with microscopic coupled-channel calculations. The potential between the colliding nuclei is determined by the double folding method with three different complex $G$-matrix interactions, the ESC, CEG07b, and MPa interactions. The CEG07b and MPa interactions, which include repulsive three-body forces, describe the data well, whereas the ESC interaction, which does not include repulsive three-body forces, fails to reproduce the data. The results provide evidence of repulsive three-body forces in $^{12}\mathrm{C}$ and demonstrate the possible sensitivity of elastic scattering to three-body forces.

The effects of three nucleon force (3NF) have been actively studied via the nucleon–deuteron (Nd) scattering states. The differential cross sections and the vector analyzing powers A y of the 2H(p, n) inclusive breakup reaction at 170 MeV were measured for the study of 3NF effects in the intermediate energy region. The polarized proton beam of 170 MeV was injected to the deuterated polyethylene (CD2) target and the energy of scattered neutrons were measured by using TOF method. The data were compared with the Faddeev calculations based on modern nucleon–nucleon (NN) forces with and without the 3NF. Concerning the differential cross sections, we can see large discrepancies between the data and the calculations in the region of scattered neutron energies are low, which is similar to the results of the 2H(p, p) inclusive breakup reaction at 250 MeV.

We have measured the 16O(p, d) reaction using 198-, 295- and 392-MeV proton beams to search for a direct evidence on an effect of the tensor interactions in light nucleus. Differential cross sections of the one-neutron transfer reaction populating the ground states and several low-lying excited states in 15O were measured. Comparing the ratios of the cross sections for each excited state to the one for the ground state over a wide range of momentum transfer, we found a marked enhancement of the ratio for the positive-parity state(s). The observation is consistent with large components of high-momentum neutrons in the initial ground-state configurations due to the tensor interactions.

Tensor correlations in 4He were studied via the (p, dp) reaction at the incident energy of 392 MeV with a focus on spin configurations of correlated pn pairs in 4He at high relative momenta \({(P_{\rm rel}^{\rm cor})}\). The preliminary results show that the correlated pn pair at \({P_{\rm rel}^{\rm cor} = 310 {\rm MeV/c}}\) predominantly has the channel spin S = 1, which is consistent with the characteristics of tensor correlations.

For the study of three nucleon force (3NF) effects in the intermediate energy region, the differential cross sections and the vector analyzing power Ay were measured for the 2H(p, n) inclusive breakup reaction at 170 MeV. The polarized proton beam of 170 MeV was injected to the deuterated polyethylene (CD2) target and the energy of scattered neutrons were deduce by TOF method. The data was compared with the results of the Faddeev calculations with and without 3NFs. Concerning about the differential cross sections, we can see large discrepancies between the data and the calculations in the region where the energies of scattered neutrons are low, which are similar to the results of the 2H(p, p) inclusive breakup reaction at 250 MeV.

Multipole strength distributions for isoscalar $L\ensuremath{\le}2$ transitions in $^{28}\mathrm{Si}$ have been extracted using 386-MeV inelastic $\ensuremath{\alpha}$ scattering at extremely forward angles, including ${0}^{\ensuremath{\circ}}$. Observed strength distributions are in good agreement with microscopic calculations for an oblate-deformed ground state. In particular, a large peak at an excitation energy of 17.7 MeV in the isoscalar giant monopole resonance strength is consistent with the calculations.

Strength distributions for isoscalar giant resonances with multipolarity $L\ensuremath{\le}2$ have been determined in $^{24}\mathrm{Mg}$ from ``instrumental background-free'' inelastic scattering of 386-MeV $\ensuremath{\alpha}$ particles at extreme forward angles, including ${0}^{\ensuremath{\circ}}$. The isoscalar $E0, E1$, and $E2$ strengths are observed to be $57\ifmmode\pm\else\textpm\fi{}7%, 111.{1}_{\ensuremath{-}7.2}^{+10.9}%$, and $148.6\ifmmode\pm\else\textpm\fi{}7.3%$, respectively, of their energy-weighted sum rules in the excitation energy range of 6 to 35 MeV. The isoscalar giant monopole (ISGMR) and quadrupole (ISGQR) resonances exhibit a prominent $K$ splitting which is consistent with microscopic theory for a prolate-deformed ground state of $^{24}\mathrm{Mg}$. For the ISGQR it is due to splitting of the three $K$ components, whereas for the ISGMR it is due to its coupling to the $K=0$ component of the ISGQR. Deformation effects on the isoscalar giant dipole resonance are less pronounced, however.

We have developed a simple one-dimensional scintillating fiber detector (SFD) for momentum tagging high-energy (a few hundred MeV per u) and high-intensity ( ∼ 10 6 particles per second, pps) beams of light ( Z ≤ 10 ) ions in the momentum-dispersive focal plane of a fragment separator. This SFD consists of 60 rows of scintillating fibers that have 2 mm square cross-sections. The detection efficiency is constant for beam intensities between 103 and 106 pps and a position detection efficiency of 100% is achieved by injecting ions obliquely. The position resolution is less than 1 mm (rms). In addition, the SFD is demonstrated to be effective for identifying particles in cocktail beams. These results show that the application of scintillating fibers is found to be one of the most suitable methods to tag the light radioactive ion beams.

The effects of three-nucleon force (3NF) has been actively studied by using the nucleon–deuteron (Nd) scattering states. The differential cross sections of the elastic Nd scattering at the energy below 150 MeV can be well reproduced by incorporating 3NF in the Faddeev calculation based on modern nucleon–nucleon (NN) interactions. On the other hand, the differential cross sections of Nd elastic and inelastic scatterings at 250 MeV show large discrepancies between the data and the Faddeev calculations with 3NF. It indicates the presence of the missing features of the three nucleon system at this energy region. For the systematic study about the energy dependence of this large discrepancies, we measured the differential cross sections and the vector analyzing power A y for the 2H(p, n) inclusive breakup reaction at 170 MeV. The experiment was carried out at RCNP by detecting scattered neutrons by using the neutron detector NPOL3. The data was compared with the results of the Faddeev calculations with and without the 3NF.

We have developed a large, thin solid hydrogen target (SHT) that is 30 mm in diameter and 1 mm thick for elastic scattering of protons from unstable nuclei. By using para-H 2 that has a high thermal conductivity at low temperatures, we could prevent sublimation at the target center due to radiation from the higher temperature surroundings. The uniform SHT was used during long-term scattering experiments and it maintained its shape and thickness.

Altitude distributions of radioactive cesium (134Cs and 137Cs) fallout at Mt. Fuji due to Fukushima Daiichi Nuclear Power Station accident have been investigated. Radioactive cesium from Fukushima Daiichi Nuclear Power Station is found to reach the height of 2,700 m. It is inferred that some amounts of radioactive cesium are attributable to the global fallout due to the nuclear weapons tests in the atmosphere.

A self-supporting target made of elemental sulfur has been developed for use in vacuum in high energy-resolution measurements at 0° using charged particle beams. The sulfur target is placed on a target ladder that is cooled by liquid nitrogen to minimize its sublimation due to heating by the energy loss of the beam in the target. Sulfur sheets with areal densities of 6–60 mg/cm2 and size of 2 × 2 cm 2 are prepared. An energy resolution of 29 keV (FWHM) in the 32 S ( p , p ′ ) experiment at 0° is achieved using a 295 MeV proton beam. The target thickness is stable within ±5% during irradiation with a beam energy loss of 0.2 mW in the target. A windowless sulfur target was used successfully for the first time.

Gamow–Teller states, possibly with narrow widths, have been searched for by the 4 He (3 He , t) reaction with an energy resolution of 100 keV. The search is motivated by theoretical discussions on the role of pions in nuclear structure and simulation of supernovae explosion. In the preliminary analysis of the spectrum at around 0°, no significant narrow structure is observed.

The cluster structures of the excited states in 11B are studied by analyzing the isoscalar monopole and quadrupole strengths in the 11B(d,d′) reaction at E d = 200 MeV . The excitation strengths are compared with the predictions by the shell-model and antisymmetrized molecular-dynamics (AMD) calculations. It is found that the large monopole strength for the 3 / 2 3 − state at E x = 8.56 MeV is well described by the AMD calculation and is an evidence for a developed three-body 2 α + t cluster structure.

8 pages, 5 figures.-- PACS nrs.: 25.40.Ep, 25.70.De.-- ISI Article Identifier: 000247257800008., Published in the Proceedings of the 2nd International Conference on Collective Motion in Nuclei under Extreme Conditions (COMEX 2). Sankt Goar, Germany, June 20-23, 2006., Experimental technique for measuring proton inelastic scattering with high-resolution at 295 MeV and at forward angles including zero degrees have been successfully developed. An excitation energy resolution of less than 20 keV, good scattering angle resolution, low background condition, and reasonable background subtraction have been achieved. The experimental technique have been applied for several sd and pf shell nuclei for systematic study M1 and E1 excitations in nuclei. The experimental method and preliminary spectra are reported.

The cluster structures of the excited states in 11 B are studied by analyzing the isoscalar monopole and quadrupole strengths in the 11 B( d , d ′) reaction at E d = 200 MeV . The excitation strengths are compared with the predictions by the shell-model and antisymmetrized molecular-dynamics (AMD) calculations. It is found that the large monopole strength for the 3 / 2 3 − state at E x = 8.56 MeV is well described by the AMD calculation and is an evidence for a developed 2 α + t cluster structure.

Collective motions of β unstable nuclei are interesting because of the uniqueness of shapes different from those of stable nuclei. Measurements of such mode of the giant resonances will supply fruitful of information unaccessible from the previous experiments. In order to access region of the sufficiently high excited energy with small momentum transfer for β unstable nuclei, we newly constructed a magnetic spectrometer for 0 degree scattered recoil particles in inverse kinematics. By means of the spectrometer we measured the H(38S,p′) reaction at forwarding angles including θ CM = 0 ° at E 38 S = 62 A MeV as the first challenge of this method. As an experimental result, a bump is confirmed at around E x = 17 MeV . Direct evidences for ISGMR of the β unstable nuclei have not yet been derived. It is hoped that the E0 strength co-exists in the observed bump.

The cluster structures of the excited states in 11B are studied by analyzing the isoscalar monopole and quadrupole strengths in the B 11 ( d , d ′ ) reaction at E d = 200 MeV . The excitation strengths are compared with the predictions by the shell-model and antisymmetrized molecular-dynamics (AMD) calculations. The large monopole strength for the 3 / 2 3 − state at E x = 8.56 MeV is well described by the AMD calculation and is suggested to be an evidence for a well developed 2 α + t cluster structure.

Differential cross sections of isoscalar and isovector spin-M1 (0(+)→1(+)) transitions are measured using high-energy-resolution proton inelastic scattering at E(p)=295 MeV on (24)Mg, (28)Si, (32)S, and (36)Ar at 0°-14°. The squared spin-M1 nuclear transition matrix elements are deduced from the measured differential cross sections by applying empirically determined unit cross sections based on the assumption of isospin symmetry. The ratios of the squared nuclear matrix elements accumulated up to E(x)=16 MeV compared to a shell-model prediction are 1.01(9) for isoscalar and 0.61(6) for isovector spin-M1 transitions, respectively. Thus, no quenching is observed for isoscalar spin-M1 transitions, while the matrix elements for isovector spin-M1 transitions are quenched by an amount comparable with the analogous Gamow-Teller transitions on those target nuclei.

The cluster structures of the excited states in 11 B are studied by analyzing the isoscalar monopole and quadrupole strengths in the 11 B (d,d′) reaction at Ed = 200 MeV . The excitation strengths are compared with the predictions by the shell-model and antisymmetrized molecular-dynamics (AMD) calculations. It is found that the large monopole strength for the [Formula: see text] state at Ex = 8.56 MeV is well described by the AMD calculation and is an evidence for a developed 2α + t cluster structure.

Experimental method of measuring inelastic proton scattering with high-resolution at forward angles including zero degrees has been developed. An energy resolution of 20 keV and a scattering angle resolution of 0.5 degrees have been achieved as well as low background condition and a reliable background subtraction method. The experimental technique was applied to the 12 C (p,p′) reaction for studying the property of the second 0+ state at 7.7 MeV and a broad bump around Ex~10 MeV , where the presence of a 2+ state was reported from the 12 C (α,α′) measurement. Preliminary spectra and angular distributions are shown.

The strength distribution of the isoscalar giant dipole resonance (ISGDR) in $^{58}$Ni has been obtained over the energy range 10.5--49.5 MeV via extreme forward angle scattering (including 0$^{\circ}$) of 386 MeV $\alpha$ particles. We observe a ``bi-modal'' ${E1}$ strength distribution for the first time in an A $, Comment: 14 pages, including 5 figures

The polarization of secondary protons from the (p, 2p) reaction induced by 1-GeV protons incident to a 4He nucleus was measured in a kinematically complete experiment. By using a two-arm magnetic spectrometer, two secondary protons from this reaction were recorded in coincidence at unequal scattering angles of Θ1 = 18°−24.21° and Θ2 = 53.22° over a broad range of the recoil-nucleus momentum K B between 0 and 150 MeV/c. It was found that the measured polarization of either secondary proton is less than that observed in free elastic proton-proton scattering. The magnitude of this difference is determined by the mean binding energy of s-shell protons rather than by the effective nuclear density. The polarizations measured in inclusive quasielastic and elastic scattering of 1-GeV protons on 4He nuclei are presented for scattering angles in the range Θ1 = 18° − 24.21°.

The cross section of the O16(p,p′)O16(0−,T=1) scattering was measured at a bombarding energy of 295 MeV in the momentum transfer range of 1.0fm−1⩽qc.m.⩽2.1fm−1. The isovector 0− state at Ex=12.8MeV is clearly separated from its neighboring states owing to the high energy resolution of about 30 keV. The cross section data were compared with distorted wave impulse approximation (DWIA) calculations employing shell-model wave functions. The observed cross sections around qc.m.≃1.7fm−1 are significantly larger than obtained by these calculations, suggesting pionic enhancement as a precursor of pion condensation in nuclei. The data are well reproduced by DWIA calculations using random phase approximation response functions including the Δ isobar that predict pionic enhancement.

We report our experimental studies on (p, 2p) reactions from two kinds of view points, namely to investigate single particle properties of nuclei and to observe possible modification of NN interactions in nuclear field. Comparison of the cross section data with theoretical predictions and data of (e, e'p) reaction suggests that the reaction mechanizsm at incident energies of around 400 MeV is simple enough to extract spectroscopic information through the (p, 2p) reactions. In addition, some analyzing power data show anomaly which is not seen in cross section data and, therefore, which suggest importance of polarization studies. On the examination of the NN interaction, systematic study on analyzing powers for 1s1/2-proton knockout has been continued. A new systematics, a Q-value dependence the analyzing power was newly observed.

Weak-interaction responses of 11B were studied by measuring the 11B(3He, t) and 11B(p, p′) reactions. Obtained nuclear transition matrix elements B(GT), B(στ), and B(σ) were compared with the shell-model calculations. The shell-model calculations, which explained the isovector parts B(GT) and B(στ) reasonably well if the quenching factors of 0.5–0.7 were taken into account, did not describe the isoscalar part B(σ).

Decay particles from the s-hole states in 11B and 15N have been measured in coincidence with the quasifree 12C(p, 2p) and 16O(p, 2p) reactions at Ep=392 MeV. Triton decay is found to be dominant for the 11B(s-hole) state and also found to be larger than α decay for the 15N(s-hole) state despite its smaller Q value compared to α decay. Measured decay branching ratios are discussed in comparison with the results of statistical-model, SU(3)-model, and shell-model calculations. The energy spectra around the s-hole states in both 11B and 15N exhibit some bumplike structures, which can be qualitatively explained by recent shell-model calculations for both nuclei.

The effective analyzing power for a 3 He polarimeter was calibrated at E 3 He =443 MeV . For the calibration, the absolute magnitude of the polarization was determined by means of the double scattering method using the 3 He scattering on 12 C at 7° in the laboratory frame. The effective analyzing power of Ayeff=0.232±0.010−0.015+0.017 was obtained for the polarimeter with a plastic scintillator of 16 mm thickness as analyzer. The energy dependence of Ayeff was measured. The first data of the induced polarization for 3 He + 12 C elastic scattering at E 3 He =443 MeV will be presented.

A new beam line that can accomplish both lateral and angular dispersion matching with the Grand Raiden spectrometer was designed and constructed at RCNP. A resolution of about 30 keV and a scattering-angle resolution of about 5 mrad were achieved in the (3He,t) reaction at T3He = 420 MeV (140 MeV/A) and angles of 0°–3°. This high-resolution and good angle-resolution reaction enables us to study nuclear structure and fine structure of giant resonances with unprecedented precision.

The isoscalar giant dipole resonance (ISGDR) in Pb-208 has been investigated with inelastic a-scattering of 400 MeV at extremely forward angles, including 0degrees. Energy spectra, virtually free from instrumental background, have been obtained and the ISGDR strength distribution has been extracted using a multipole-decomposition analysis (MDA). A difference-of-spectra approach yields the same ISGDR centroid energy as with MDA. These results lead to a value for nuclear incompressibility that is consistent for both the isoscalar dipole and monopole modes. (C) 2003 Elsevier Science B.V All rights reserved.

For precise measurements of nuclear-reaction spectra using a beam from an accelerator, a high-resolution magnetic spectrometer is a powerful tool. The full capability of a magnetic spectrometer, however, can be achieved only if the characteristics of the beam coming from the accelerator are matched to those required by the spectrometer by properly adjusting the beam line conditions. The matching methods, lateral dispersion matching, focus matching and also the kinematic correction compensate the spectrum line-broadening effects caused by the beam momentum spread and reaction kinematics. In addition, angular dispersion matching should be performed if good resolution of the scattering angle is important. Diagnostic methods developed to realize these matching conditions for the spectrometers K600 at IUCF and Grand Raiden at RCNP are presented.

We report on experimental investigation of the (p, 2p) reactions on nuclei 6Li, 7Li, 12C and 40Ca. In this experiment, polarizations of the secondary protons from the (p, 2p) reactions are measured using 1 GeV proton beam of the PNPI synchrocyclotron. Two final protons from the reaction are detected in coincidence by means of a two-arm magnetic spectrometer at non-symmetric scattering angles. The resolution of the spectrometer on separation energy of 4.5 MeV (FWHM) is enough to distinguish reliably the shell structure of the investigated nuclei. In order to measure polarization of the two secondary protons, both spectrometer arms are equipped with multiwire proportional chamber polarimeters. Strong reduction of polarizations (large depolarization factor) relatively to free pp scattering is observed in the experiment. The 6Li, 7Li P-shell data are interpreted in terms of this reduction being combined with classical phenomenon of the effective polarization calculated with the help of DWIA. For the S-shell protons the depolarization factors are apparently seen not being obscured by the spin-orbit coupling. In case of the 7Li S-shell data the depolarization factors calculated by deviation from IA are found to be ΔP/P=0.31±0.07 and 0.39±0.04 for the scattered and recoil proton polarization, respectively. As estimations show, significant and roughly equal polarization reduction of the two secondary protons with essentially different energies (≈-200 and 800 MeV) can hardly be explained by a trivial nuclear distortion effect like depolarization due to rescatterings in nuclear matter. Measurements with heavier nucleus targets (12C, 40Ca) show that magnitude of the depolarization is a decreasing function of the nuclear density in the part of the nucleus volume which effectively contributes to the pp scattering in a nucleus. An explanation of the observed depolarization might be done in terms of modification of the pp-scattering amplitude in the nuclear meidum.

A windowless and self-supporting ice target is described. An ice sheet with a thickness of 29.7 mg/cm$^2$ cooled by liquid nitrogen was placed at the target position of a magnetic spectrometer and worked stably in the $^{16}$O$(p,p')$ experiment at $E_{p}=392$ MeV. Background-free spectra were obtained., Comment: 14 pages, 4 figures, Nucl. Instr. & Meth. A (in press)

Isoscalar giant resonances and low spin states in $^{32}$S have been measured with inelastic $\alpha$ scattering at extremely forward angles including zero degrees at E$_{\alpha}$ = 386 MeV. By applying the multipole decomposition analysis, various excited states are classified according to their spin and parities (J$^{\pi}$), and are discussed in relation to the super deformed and $^{28}$Si + $\alpha$ cluster bands.

Introduction of a magnetic spectrometer for the analysis of nuclear reaction products can open a new dimension in structure studies as well as reaction studies through the capability of achieving high-resolution and low-background measurements. Ion-optical matching methods to achieve better energy (momentum) resolutions than those inherent to the incident beam causing the reaction are described for a magnetic spectrometer using beams from an accelerator. They are the lateral dispersion matching, focus matching and also the kinematic correction. In addition the angular dispersion matching should be performed if better resolution of the scattering angle is important. These conditions are described in the first order approximation of ion optics. The diagnostic methods to realize the conditions of lateral dispersion matching and angular dispersion matching condition are briefly presented. The method described here can be applied for a good resolution spectroscopy of a reaction using a beam from ion source or a secondary beam with a larger energy spread.

Polarization transfer (PT) observables in the 12 C (p,p′) reaction at 0° for 392 MeV protons have been measured. The excitation strengths are decomposed into the spin-flip part and the non-spin-flip part by using the obtained PT observables. The PT observables for excitation of the 1+, T=0 and 1+, T=1 states are compared with distorted wave impulse approximation calculations. The strength ratios of the isoscalar spin-dependent term to the isovector tensor term and the isovector tensor term to the isovector spin-dependent term are reasonably consistent with the Franey and Love interaction.