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The RANS (RIKEN Accelerator driven Neutron Source), one of compact accelerator neutron sources (CANS), tries to expand its performance by installing a cold neutron which may provide new opportunities in many applications. RANS is a low power CANS with a proton beam of 7 MeV and 100 µA at maximum. A moderator system was constructed based on results of optimization design study with mesitylene. Recently, we have done performance tests aiming at showing characteristics as cold neutron source. Cryogenic mesitylene moderator was installed on a plug with a new target moderator reflector configuration of RANS. Experiment using a gas electron multiplier (GEM) detector was carried out to measure neutron spectra of the cold moderator. This paper describes performance of the cold moderator in terms of 1) Cold neutron gain of optimization design with respect to a polyethylene moderator, 2) Temperature dependency of cold neutron spectrum flux regarding scattering kernel (SK), and 3) comparison between experiment and calculation. A note is given for comparison between calculations with different SKs available. Also, two-dimensional imaging of cold and thermal neutron spectrum flux on the viewed surface is shown with a pinhole slit configuration.

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.

In order to study the nucleus–nucleus interactions for syntheses of superheavy nuclei, we measured excitation functions for the quasielastic scattering of 48Ca+208Pb, 50Ti+208Pb, and 48Ca+248Cm using the gas-filled-type recoil ion separator GARIS. The quasielastic scattering events were clearly separated from deep-inelastic events by using GARIS and its focal plan detectors, except for high-incident-energy points. The quasielastic barrier distributions were successfully extracted for these systems, and compared with coupled-channels calculations. The results of the calculations indicate that vibrational and rotational excitations of the colliding nuclei, as well as neutron transfers before contact, strongly affect the structure of the barrier distribution. For the reactions of 48Ca+208Pb and 50Ti+208Pb, a local maximum of the barrier distribution occurred at the same energy as the peak of the 2n evaporation cross section of the system. On the other hand, for the hot fusion reaction of 48Ca+248Cm, the 4n e...

A blow-in type windowless thick He gas target has been developed to measure 4He(12C,16O) γ cross section for astrophysical interests. We use a 12C beam of energy from 6 to 2.8 MeV and detect 16O recoils at forward angles. Numerous 12C backgrounds have been rejected by particle identification techniques. 16O backgrounds from the target are not many but fatally harmful. Our techniques to reduce the 16O backgrounds are described.

A chiral complex, [Fe(HL)2](PF6)2 (1), where HL denotes 2-pyridylmethylidenehydrazono-4-(2-methylimidazolyl)methane, was prepared. X-ray structure analysis revealed that it crystallizes as a kryptoracemate of sesquihydrate chiral crystals in the orthorhombic noncentrosymmetric space group P212121 (Z = 8, Z′ = 2). Two diastereomeric cationic complexes with opposite configuration reside within the asymmetric unit. KBr pellets prepared using selected single crystals showed enantiomorphous circular dichroism patterns.

In astrophysics, He-4(C-12,O-16)gamma reaction places an important role. At Kyushu University Tandem accelerator Laboratory (KUTL), the measurement of He-4(C-12,O-16)gamma cross section is in progress in the energy range of astrophysical nuclear reaction. Since the charge state of product O-16 ions after passing through the gas target is spread and only one charge state can be measured at terminal detector, it is necessary to know the charge state distribution of O-16 ions passing through the He gas target precisely. Here, we report the charge state distribution of the O-16 recoils both experimentally and theoretically. Experimentally, we measured the equilibrium charge state distribution of O-16 ions in the windowless helium gas target with the beam energy of primary O-16 ions at 7.2, 4.5, and 3.45 MeV at KUTL. The measured results showed a Gaussian distribution for the charge state fraction. Theoretically, we proposed a framework for the charge state distribution study. Charge state distribution was computed by solving a set of differential equations including a series of charge exchange cross sections. For the ionization cross section, plane-wave Born approximation was applied and modified by taking target atomic screening as a function of momentum transfer into account. For the capture cross section, continuum distorted wave approximation was applied and the influence of the gas target density was taken into account in the process of electron capture. Using above charge exchange cross sections, the charge state evolution was simulated. According to the equilibrium distribution, we compared the theoretical calculation to the experimental data. After taking into account the density effects in the charge exchange process, the theoretical charge state distributions shows a good agreement with the experimental data. Both experimental and theoretical results are useful to understand the charge fraction of recoil oxygen created via He-4(C-12,O-16)gamma reaction, especially in the energy range of astrophysical nuclear reaction. (C) 2014 Elsevier B.V. All rights reserved.

We present a preliminary self-consistent numerical model of solid-state convection in a wet mantle with magmatism and tectonic plates to understand how magmatism and tectonic plates affect circulation of water injected into deep mantle. The solidus temperature of mantle materials depends on water-content, but their water-saturation limit is assumed to be constant and water-content dependence of viscosity is neglected. When the mantle is mildly heated by heat producing elements, plate tectonics steadily occurs, and subducted basaltic crusts accumulate on the core-mantle boundary. Water injected into deep mantle is mostly transported to basaltic accumulation areas, which serve as a major storage of injected water. The characteristic time for the water-circulation is 2–6 Gyr. Water significantly enhances magmatism. When the mantle is more strongly heated and the internal heating rate exceeds a threshold, however, basaltic accumulations become convectively unstable, cause vigorous magmatism, and split the lithosphere into smaller fragments. Water transported into deep mantle by subducting lithospheric fragments distributes more uniformly, and the water storage capacity of the mantle becomes much smaller than that under the mild internal heating below the threshold. The characteristic time for water-circulation is 1–2 Gyr. The characteristic time of water-circulation in the mantle is comparable to the age of the Earth under mild internal heating, and the water-circulation depends on the regime of magmatism and mantle convection, which in turn depends on the internal heating rate; a full understanding of dynamics of magmatism and mantle convection is crucial for understanding water-circulation in the mantle and the effect of water on mantle evolution.

A cross section measurement employing a direct 16O detection method for the reaction energies from E cm = 2.4 to 0.7 MeV is planned at Kyushu University Tandem Laboratory. To perform this experiment and to obtain quantitative information about the cross section to within an error of 10%, we have developed several instruments, including a blow-in type windowless gas target and a ionization chamber. A target thickness of 24 × 3.9 Torr cm was achieved using the developed gas target. The particle identification was successfully performed by using the energy deposit in the ionization chamber. Experiments were performed at E cm = 2.4 and 1.5 MeV using the developed instruments and the cross sections were obtained.

12C+4He fusion reaction at Ecm = 0.3 MeV is one of the main reaction in 4He-burning in stars, and is very important in nuclear synthesis. However the fusion cross section has not been determined yet in spite of 40 years efforts in the world. Recently we succeeded in the measurement at 1.5 MeV. We have a plan to make direct measurement of the total fusion cross section down to 0.7 MeV at Kyushu University Tandem accelerator Laboratory (KUTL), and to determine the cross section at 0.3 MeV by extrapolation.

症例は58歳の男性で，上腹部の痛みと体重減少にて近医受診し，腹部USにて膵体部に低エコー腫瘤を認め当院に紹介された．腹部CTにて膵体部に5cm大の造影効果の乏しい腫瘍と，末梢膵管の著明な拡張を認めたため膵体部癌と診断し，膵体尾部切除を行った．病理組織学的に腫瘍は主膵管および周囲の小範囲に浸潤性膵管癌を認める以外，浸潤部のほとんどに広範な異型の強い紡錘形細胞の増殖と線維化を認めた．各種免疫染色検査においてこれらの紡錘形細胞は間葉系マーカーに陽性を示した．以上より，膵体部に発生した癌肉腫と診断した．術後6か月経過したが，再発兆候はなく，補助化学療法としてgemcitabine投与を行っている．膵癌肉腫は極めてまれでまた治癒切除が施行された場合でも再発し，急速に進行し予後不良とされている．今後は化学療法を含めた集学的治療の確立のため，さらなる症例数の蓄積が必要と考えられた．

Mononuclear [Fe(H2LR)2]X2 (R = H, 2-Me, 5-Me, 2-Et-5-Me; X = ClO4, BF4) and dinuclear [Fe2(H2LR)3]X4 complexes containing imidazole-4-carbaldehyde azine (H2LH) and its derivatives prepared by condensation of 4-formylimidazole, 2-methyl- or 5-methyl-4-formylimidazole, or 2-ethyl-4-methyl-5-formylimidazole, with hydrazine in a 2:1 mole ratio in methanol, were prepared and their magnetostructural relationships were studied. In the mononuclear complexes, H2LR acts as an unsymmetrical tridentate ligand with two imidazole nitrogen atoms and one azine nitrogen atom, while in the dinuclear complexes, H2LR acts as a dinucleating ligand employing four nitrogen atoms to form a triple helicate structure. At room temperature, [Fe2(H2LH)3](ClO4)4 and [Fe2(H2L2-Me)3](ClO4)4 were in the high-spin (HS) and low-spin (LS) states, respectively. The results are in accordance with the ligand field strength of H2L2-Me with electron-donating methyl groups being stronger than H2LH, with the order of the ligand field strengths being H2L2-Me > H2LH. However, in the mononuclear [Fe(H2LH)2](ClO4)2 and [Fe(H2L2-Me)2](ClO4)2 complexes, a different order of ligand field strengths, H2LH > H2L2-Me, was observed because [Fe(H2LH)2](ClO4)2 was in the LS state while [Fe(H2L2-Me)2](ClO4)2 was in the HS state at room temperature. X-ray structural studies revealed that the interligand steric repulsion between a methyl group of an H2L2-Me ligand and the other ligand in [Fe(H2L2-Me)2](ClO4)2 is responsible for the observed change in the spin state. The same is true for [Fe(H2L2-Et-5-Me)2](ClO4)2, while [Fe(H2L5-Me)2](ClO4)2 does not involve such a steric congestion and stays in the LS state over the temperature range 5–300 K. Two kinds of crystals (polymorphs) were isolated for [Fe2(H2LH)3](BF4)4 and [Fe2(H2L2-Et-5-Me)3](ClO4)4, and they exhibited different magnetic behaviors.

Mononuclear [Fe(H2L2-Et-5-Me)2]2+ and dinuclear [Fe2(H2L2-Et-5-Me)3]4+ complexes, where H2L2-Et-5-Me denotes 2-ethyl-5-methylimidazole-4-carbaldehyde azine, were prepared and isolated as the perchl...

We have developed a tracking detector with a gas electron multiplier (GEM) for nuclear experiments. The developed GEM detector was installed inside the dipole magnet used for transporting the primary beam to the beam dump and it was used to measure the momentum of charged particles. A sufficiently high spatial resolution was achieved at a high counting rate and a magnetic field for coherent pion production with a 392 MeV proton beam to study the short-range component of the residual nuclear interaction. The detector systems and development procedure are described.

Mononuclear [Fe(H(2)L(R))(2)](2+) and dinuclear [Fe(2)(H(2)L(R))(3)](4+) (R = H, 2-Me, 5-Me) complexes containing the new imidazole-4-carbaldehyde azine ligand (H(2)L(H)) and its derivatives (H(2)L(2-Me) and H(2)L(5-Me)) prepared from the condensation reaction of 4-formylimidazole or 2-methyl- or 5-methyl-4-formylimidazole with hydrazine (2:1) were prepared, and their magnetostructural relationships were studied. In the mononuclear complexes, H(2)L(R) acts as an unsymmetrical tridentate ligand with two imidazole nitrogen atoms and one azine nitrogen atom, while in the dinuclear complexes, H(2)L(R) acts as a dinucleating ligand employing four nitrogen atoms to form a triple helicate. At room temperature, [Fe(2)(H(2)L(H))(3)](ClO(4))(4) and [Fe(2)(H(2)L(2-Me))(3)](ClO(4))(4) were in the high-spin (HS) and low-spin (LS) states, respectively. The results are in accordance with the ligand field strength of H(2)L(2-Me) with electron-donating methyl groups being stronger than H(2)L(H), with the order of the ligand field strengths being H(2)L(2-Me)H(2)L(H). However, in the mononuclear [Fe(H(2)L(H))(2)](ClO(4))(2) and [Fe(H(2)L(2-Me))(2)](ClO(4))(2) complexes, a different order of ligand field strengths, H(2)L(H)H(2)L(2-Me), was observed because [Fe(H(2)L(H))(2)](ClO(4))(2) was in the LS state while [Fe(H(2)L(2-Me))(2)](ClO(4))(2) was in the HS state at room temperature. X-ray structural studies revealed that the interligand steric repulsion between a methyl group of an H(2)L(2-Me) ligand and the other ligand in [Fe(H(2)L(2-Me))(2)](ClO(4))(2) is responsible for the observed change in the spin state. Two kinds of crystals, needles and blocks, were isolated for [Fe(2)(H(2)L(H))(3)](BF(4))(4), and both exhibited a sharp spin transition, [LS-HS]--[HS-HS]. The spin transition of the block crystals is more abrupt with a hysteresis, T(c) upward arrow = 190 K and T(c) downward arrow = 183 K with DeltaT = 7 K.

We made again an experiment of pd radiative capture at [Formula: see text], and obtained Axx, Ayy and Azz (= -Axx - Ayy) data using a newly-developed data-analysis method of high detection efficiency. Re-analysis of previous data on Axx and Ayy was also made using a new method. All the new and previous data at 197 MeV agree to each other, and Axx anomaly has been confirmed.

症例は56歳，女性．下血を主訴に当院を受診し，大腸内視鏡検査で直腸に粘膜下腫瘍様病変を認め精査目的に入院となった．生検にて胞体がクリアな腫瘍細胞を認め，子宮・卵巣由来の悪性腫瘍が考えられたが，子宮および卵巣摘出術後状態であり診断に難渋した．直腸癌の可能性も否定できず，低位前方切除術を施行した．腫瘍は直腸壁外に主座をおき直腸内腔に潰瘍を形成した病変で，組織型はclear cell adenocarcinomaであった．腫瘍周囲の直腸壁内に子宮内膜組織を認めたため直腸子宮内膜症の癌化と診断した．術後18カ月経過した現在，再発の徴候は認めていない．腸管子宮内膜症の癌化は稀な症例であり報告する．

We report measurements of the cross section and a complete set of polarization observables for the Gamow–Teller C 12 ( p → , n → ) N 12 ( g.s. , 1 + ) reaction at a bombarding energy of 296 MeV. The data are compared with distorted wave impulse approximation calculations employing transition form factors normalized to reproduce the observed beta-decay ft value. The cross section is significantly under-predicted by the calculations at momentum transfers q ≳ 0.5 fm −1 . The discrepancy is partly resolved by considering the non-locality of the nuclear mean field. However, the calculations still under-predict the cross section at large momentum transfers of q ≃ 1.6 fm −1 . We also performed calculations employing random phase approximation response functions and found that the observed enhancement can be attributed in part to pionic correlations in nuclei.

Inelastic α scattering on 16 O is studied at 400 MeV using an ice target. Near the 4 α breakup threshold of 14.4 MeV, a broad peak is observed at an excitation energy of 13.6 ± 0.1 MeV with a width of 0.6 ± 0.2 MeV . The spin-parity is estimated to be 0 + from the momentum-transfer dependence. The observed width is significantly larger than that of the 0 + state at 12.0 MeV with the α + C 12 structure, indicating a well-developed α cluster structure. The magnitude of the cross section is sensitive to the density distribution of the constituent α clusters. The observed cross section is consistent with the theoretical prediction for the α cluster condensed state, characterized by its dilute density distribution with a large root-mean-square radius.

The cross sections and spin observables of the pd elastic scattering have been measured at 392 MeV. The results are compared with the prediction of Faddeev calculations with and without including a three nucleon force.

We report measurements of the cross section and a complete set of polarization observables for the Si 28 ( p → , n → ) P 28 ( 6 − ) reaction at a bombarding energy of 198 MeV. The data are compared with distorted wave impulse approximation calculations employing response functions normalized to inelastic electron scattering. The spin-longitudinal polarized cross section I D q is slightly over-predicted by the calculations, while the normal spin-transverse polarized cross section I D n is significantly under-predicted. The calculated in-plane spin-transverse I D p and spin-scalar I D 0 polarized cross sections agree well with the experimental data. These results are consistent with those for Si 28 ( p → , p → ′ ) Si 28 ( 6 − , T = 1 ) scattering at the same energy, and thus it is concluded that isospin-mixing effects are not responsible for the discrepancy between theory and experiment in the ( p → , p → ′ ) case. Energy half-off-shell effects as medium effects on the effective nucleon–nucleon interaction are also investigated and found to be too small to be responsible for the discrepancy.

A cross section measurement employing a direct 16O detection method for the reaction energies from Ecm = 2.4 to 0.7 MeV is planned at Kyushu University Tandem Laboratory (KUTL). To perform this experiment and to obtain quantitative information about the cross section to within an error of 10%, we have developed several instruments, including a blow-in type windowless gas target, a recoil mass separator and a RF-deflector. The measurements at Ecm = 2.4 and 1.5 MeV have been performed with these instruments. For measuring at Ecm < 1.2 MeV, a hybrid detector employing both, an ionization chamber and a silicon detector was developed to reduce the carbon backgrounds more efficiently. The oxygen ions were clearly separated from carbon background by using the energy deposit in the ionization chamber. Experiment of Ecm = 1.2 MeV was performed and the cross section was obtained.

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 two charge exchange reactions 14N(d, 2He)14C and 14N(3He, t)14O were studied with high resolution in order to identify the Gamow–Teller (GT) strength distribution starting from the ground state (g.s.) of 14N in the β− and β+ directions. The isospin symmetry in the A = 14 mass system is investigated. An overview of the main features of the experimental investigation is summarized here.

In order to study the Gamow–Teller (GT) transitions in the fp-shell nucleus 64Cu, the 64Ni(3He, t)64Cu charge-exchange reaction was investigated at MeV/nucleon [1]. The outgoing tritons were momentum analysed by the Grand Raiden spectrometer at 0°. The very high energy resolution of 35 keV (FWHM) allowed the separation of individual levels in the excitation energy region from 0 to 3.5 MeV. An angular distribution analysis was performed for the observed transitions to these states. In addition to the ground state (g.s.), known to be a Jπ = 1+ GT state, several excited states showed L = 0 nature, making them candidates of GT states. At higher excitation energies, the level density becomes very high and a bump-like structure, the so-called GT Giant Resonance, dominates the spectrum.

Thin self-supporting targets are indispensable in high energy-resolution studies using a magnetic spectrometer. However, nuclear targets of alkaline and alkaline-earth metal or halogen isotopes are not easily available. In order to produce thin target foils of these elements for the use in charge-exchange reactions, we take advantage of the fact that the stable isotopes of these elements have relatively small negative Q values, while 12 C and 16 O have large negative Q values. Therefore, even if organic compounds containing carbon and oxygen are used as supporting material, clean spectra on alkaline and alkaline-earth metal or halogen targets can be obtained up to the excitation energies of Q-value differences. A technique to produce thin foils of the chemical compounds Na 2 CO 3 , K 2 CO 3 , CaCO 3 and CaCl2 was developed using polyvinylalcohol as supporting material. Foils with a total thickness of 1– 2 mg / cm 2 were produced and used as targets in a ( 3 He ,t) reaction study at an incident energy of 420 MeV . Owing to the small contributions of energy-loss differences of beam and reaction products in such thin targets, a very good resolution of ΔE/E=7×10−5 was achieved in combination with a high-resolution magnetic spectrometer.

To study the three-nucleon force (3NF) effects without ambiguities from the Coulomb effect, the differential cross sections and the vector analyzing powers for the [Formula: see text] elastic scattering at En = 245 MeV have been measured at θcm = 85° - 180°. The data are compared to the results of Faddeev calculations using modern nucleon-nucleon (NN) forces with and without 3NF. Additionally we have a plan to extend our measurement to the forward angular region where the Coulomb effect is expected to be large. We carried out the test experiment and measured the differential cross sections at θcm = 21°.

The fusion reaction 48Ca + 248Cm → 296Lv* was investigated using the gas-filled recoil ion separator GARIS at RIKEN. The reaction was studied at excitation energies of 41.3 and 38.2 MeV. A total of seven decay chains were observed. Three of the chains were assigned to the decay of 292Lv and three to the decay of 293Lv. A possible observation of an α-decay branch of 284Cn populating the new spontaneously fissioning nucleus 280Ds is discussed. The assignment of one of the decay chains to the 3n evaporation channel, resulting in a spontaneous fission branch of 285Cn, or to the 2n channel, resulting in the population of the new fissioning nucleus 286Cn, is ambiguous. Measured cross sections are in agreement with previously published values.

The reaction 12C + 4He → 16O + γ at Ecm = 0.3 MeV plays an important role in stellar evolution, but the reaction cross section has not been measured yet. Recently we succeeded to measure total cross section of the reaction down to Ecm = 1.5 MeV at Kyushu University. We have a plan to measure the cross section down to 0.7 MeV in several years, and to extrapolate the results to 0.3 MeV.

A fusion reaction of 12C+4He→16O+γ is one of the main reactions in He-burning of stars and important for nucleosynthesis. The fusion cross section at stellar energy of Ecm=0.3 MeV has not been determined precisely yet in spite of efforts for about 40 years. We plan to measure directly the total fusion cross section down to 0.7 MeV at Kyushu University Tandem accelerator Laboratory and to estimate the cross section at 0.3MeV by extrapolation. We have already measured the cross sections at 2.4 MeV and 1.5 MeV. The measurement at Ecm=1.2 MeV is in progress.

患者は72歳の男性. 大動脈周囲リンパ節転移と肝転移H2を伴う2型進行胃癌に対し, 胃全摘・膵脾合併切除, 肝転移巣切除, D4リンパ節郭清を行ったが, 大動脈周囲リンパ節が完全摘除できず, 非治癒切除となった. 術後化学療法として, 5-FU, adriamycin, mitomycin C (MMC)の肝動注, doxifluridineの内服, および, cisplatin, MMC, etoposide, pirarubicinの静注を行い, 外来でtegafur内服とlentinan静注を継続した. 遺残した大動脈周囲リンパ節転移は術後1年6か月の腹部CTスキャンで消失し, complete responseが5か月間得られた. 患者の状態は良好に保たれ, 血清CEAとimmunosuppressive acidic proteinは術後4年6か月まで正常値を維持した. 術後5年2か月に縦隔リンパ節再発により死亡したが, 肝再発は認めなかった. 本症例の長期生存には, 減量手術と術後早期の導入化学療法が奏効したことに加え, 長期の維持免疫化学療法が寄与したことが示唆された.

The double-differential cross sections for the ${}^{116}$Cd$(p,\phantom{\rule{-0.16em}{0ex}}n)$ and ${}^{116}$Sn$(n,\phantom{\rule{-0.16em}{0ex}}p)$ reactions were measured at 300 MeV for studying the nuclear matrix element of the ${}^{116}$Cd $\ensuremath{\beta}\ensuremath{\beta}$ decay. A multipole decomposition technique was applied to the spectra to extract the Gamow-Teller (GT) component. The integrated GT strengths up to an excitation energy of 30 MeV in the intermediate nucleus ${}^{116}$In are $40\ifmmode\pm\else\textpm\fi{}6$ and $11\ifmmode\pm\else\textpm\fi{}1$ in the $(p,\phantom{\rule{-0.16em}{0ex}}n)$ and $(n,\phantom{\rule{-0.16em}{0ex}}p)$ spectra, respectively, including the component from the isovector spin monopole (IVSM). The spectra are compared with those obtained from a theoretical calculation with a quasiparticle random phase approximation, where the contribution from the IVSM component as well as the interference effect between the GT and IVSM components are fully taken into account.

Scattering of protons of several hundred MeV is a promising new spectroscopic tool for the study of electric dipole strength in nuclei. A case study of 208Pb shows that at very forward angles J^pi = 1- states are strongly populated via Coulomb excitation. A separation from nuclear excitation of other modes is achieved by a multipole decomposition analysis of the experimental cross sections based on theoretical angular distributions calculated within the quasiparticle-phonon model. The B(E1) transition strength distribution is extracted for excitation energies up to 9 MeV, i.e., in the region of the so-called pygmy dipole resonance (PDR). The Coulomb-nuclear interference shows sensitivity to the underlying structure of the E1 transitions, which allows for the first time an experimental extraction of the electromagnetic transition strength and the energy centroid of the PDR., Comment: submitted to Phys. Rev. C

A benchmark experiment on Pb-208 shows that polarized proton inelastic scattering at very forward angles including 0 degrees is a powerful tool for high-resolution studies of electric dipole (E1) and spin magnetic dipole (M1) modes in nuclei over a broad excitation energy range to test up-to-date nuclear models. The extracted E1 polarizability leads to a neutron skin thickness r(skin) = 0.156(-0.021)(+0.025) fm in Pb-208 derived within a mean-field model [Phys. Rev. C 81, 051303 (2010)], thereby constraining the symmetry energy and its density dependence relevant to the description of neutron stars.

x-ray bursts are identified as thermonuclear explosions in the outer atmosphere of accreting neutron stars. The thermonuclear runaway is fueled by the alpha p process that describes a sequence of (alpha,p) reactions triggered by the Ne-18(alpha,p)Na-21 breakout reaction from the hot CNO cycles. We studied the level structure of the compound nucleus Mg-22 by measuring the Mg-24(p,t)Mg-22 reaction at the Grand Raiden spectrometer at Research Center for Nuclear Physics, Osaka. A large number of alpha-unbound states was identified and precise excitation energies were determined. Based on shell model and alpha-cluster model calculations we predict the level parameters for determining the stellar reaction rate of Ne-18(alpha,p)Na-21 for a wide temperature range. x-ray burst simulations have been performed to study the impact of the reaction on the x-ray burst luminosity.

[1] A series of self-consistent numerical models of mantle convection with magmatism and moving plates are presented to clarify the dynamics of the strongly heated mantle of the earliest Earth. Broad hot accumulations of subducted basaltic crusts develop on the core-mantle boundary and remain there for geologic time only when the internal heating rate is below a threshold. Above the threshold, the basaltic accumulations become unstable. Instead, the thermal buoyancy induced by the strong internal heating repeatedly causes a massive upwelling, or burst, of hot materials from deep mantle. The mantle burst induces vigorous magmatic activity on the surface. The magmatic activity, in turn, damages the lithosphere and disintegrates it into smaller fragments. In contrast to the well-ordered plate motion observed below the threshold, the lithospheric fragments chaotically move and new subduction zones sporadically develop. The mantle burst and chaotic motion of lithospheric fragments effectively stir the mantle, and the mantle remains chemically rather homogeneous in spite of the chemical differentiation due to the vigorous magmatism. The Earth's mantle convection has probably changed its regime from one dominated by frequent mantle bursts and chaotic motion of lithospheric fragments to one dominated by stable basaltic accumulations and well-ordered plate motion, as the internal heat source decays. The suggested regime transition fits in with the Earth's tectonic evolution inferred from geologic observations of the continents of various ages.

To study the Gamow-Teller (GT) transitions to the pf-shell nucleus Cu-64, the Ni-64(He-3,t)Cu-64 experiment was performed at the Research Center for Nuclear Physics (RCNP) Ring Cyclotron, Osaka, using a He-3 beam of 140 MeV/nucleon. The outgoing tritons were momentum analyzed by the Grand Raiden spectrometer at 0(degrees). A high energy resolution of 32 keV (full width at half-maximum) allowed the separation of individual levels in the excitation-energy region from 0 to 3.5 MeV. In addition to the ground state (gs), known to be a J(pi)=1(+) GT state, many low-lying states showed L=0 nature, suggesting that they are candidates for GT states. Because the GT strength B(GT) for the gs transition is known from the beta-decay measurement, the strengths for the excited states could be determined using the proportionality between the B(GT) and the reaction cross section extrapolated to q=0 momentum transfer. At higher excitation energies, the level density becomes high and the so-called GT giant resonance dominates the spectrum. The lower and the upper limits of the strength contained in this energy region were estimated. Our results show that less than 55% of the strength predicted by the Ikeda sum rule is located in the excitation-energy region from 0 to 17 MeV..

Gamow-Teller (GT) unit cross sections, ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$, are obtained at 198 and 297 MeV by measuring the double differential cross sections at ${0}^{\ifmmode^\circ\else\textdegree\fi{}}$ for the $(p,n)$ reaction on $^{58}\mathrm{Ni}$, $^{70}\mathrm{Zn}$, $^{114}\mathrm{Cd}$, $^{118}\mathrm{Sn}$, and $^{120}\mathrm{Sn}$. The mass dependence of ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ and the ratio of ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ to the Fermi unit cross section, ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{F}}$, $({R}^{2})$ are also derived in the mass region of $58\ensuremath{\leqslant}A\ensuremath{\leqslant}120$. The ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ value for $^{90}\mathrm{Zr}$ at 297 MeV interpolated using the $A$-dependence obtained herein agrees with that used in a previous analysis where the GT transition strength over a wide energy region up to the continuum was discussed. However, the deduced $^{64}\mathrm{Ni}$${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ value at 198 MeV is 20% smaller than that obtained from the analysis of a previous $(n,p)$ measurement. The present ${R}^{2}$ values in the mass region heavier than $^{42}\mathrm{Ca}$ are larger than those in the region up to $^{42}\mathrm{Ca}$ and increase as a function of $A$.

We measured the differential cross section and the spin correlation parameter C{sub yy} of the p-vector+{sup 3}He-vector elastic backward scattering at 200, 300, and 400 MeV at {theta}=180 deg. in the center-of-mass frame to study the mechanism of the reaction and to examine the validity of the {sup 3}He wave functions based on two different realistic two-body forces. This is the first measurement of the spin correlation parameter C{sub yy} of the p-vector+{sup 3}He-vector EBS at intermediate energies. The experimental results were compared with few-body calculations, including three reaction mechanisms: two-nucleon-pair exchange, pion exchange, and direct pp scattering. It was found that few-body calculations describe the differential cross-section data reasonably well. The spin correlation parameter C{sub yy} shows clear evidence for the two-nucleon-pair exchange processes in the reaction, demonstrating that the spin observables are helpful for deeper understanding of the reaction mechanism.

A complete set of polarization transfer observables has been measured for the $^{12}{\rm C}(p,n)$ reaction at $T_p=296 {\rm MeV}$ and $\theta_{\rm lab}=0^{\circ}$. The total spin transfer $\Sigma(0^{\circ})$ and the observable $f_1$ deduced from the measured polarization transfer observables indicate that the spin--dipole resonance at $E_x \simeq 7 {\rm MeV}$ has greater $2^-$ strength than $1^-$ strength, which is consistent with recent experimental and theoretical studies. The results also indicate a predominance of the spin-flip and unnatural-parity transition strength in the continuum. The exchange tensor interaction at a large momentum transfer of $Q \simeq 3.6 {\rm fm}^{-1}$ is discussed., Comment: 4 pages, 4 figures

Gamow-Teller (GT) transition is the most popular nuclear weak process with the nature of spin-isospin excitation. GT transitions in pf -shell nuclei, including those starting from unstable nuclei, are of interest, due to their importance in astrophysical processes. Weak processes, however, gives us rather limited information on the GT response of nuclei. We introduce high-resolution ( 3 He ,t )reactionat0 ◦ and at an intermediate beam energy as a new spectroscopic tool for studying GT excitations. Owing to the high energy-resolution of the reaction ( ≈ 30 keV), individual transitions can be observed up to the region of GT giant resonance. Assuming isospin symmetry for the T z = ± 1 → 0 isobaric analogous transitions in isobars with mass number A , we present a new method to deduce GT transition strengths starting from proton rich exotic nuclei. ispartof: pages:70- ispartof: Nuclear Physics A vol:788 issue:1-4 pages:70- ispartof: 2nd International Conference on Collective Motion in Nuclei Under Extreme Conditions location:St Goar: GERMANY date:20 Jun - 23 Jun 2006 status: published

The short range component of the nucleon‐nucleus interaction is phenomenologically described by effective interaction including the so‐called Landau‐Migdal parameters g′, among which only gΔΔ′ has been left unfixed because of the scarcity of experimental information. We propose Coherent Pion Production (CPP) measurement 12C(p, nπ+)12C(g.s.) to get quantitative information on gΔΔ′. A preliminary CPP experiment was performed at the RCNP neutron time of flight facility by involving exclusive measurement of pions and neutrons. We have specially developed for this purpose a new pion counter and embedded it in the beam swinger magnet of the neutron time of flight facility. We describe the experiment and preliminary result from the pion‐neutron coincidences.

Supernarrow dibaryons (SNDs) have been searched for by the $\mathit{pd}\ensuremath{\rightarrow}\mathit{ppX}$ and $\mathit{pd}\ensuremath{\rightarrow}\mathit{pdX}$ reactions at ${E}_{p}=295$ MeV over a mass range of 1898 to 1953 MeV, where three candidates of SNDs were found at the Moscow Meson Factory. The experiment was carried out at the Research Center for Nuclear Physics using a two-arm magnetic spectrometer system and a liquid deuterium target. A good mass resolution of 1 MeV and a low background condition were achieved. No resonance structure was observed in the missing mass spectra. Upper limits of the SND production cross section were determined.

A new experimental approach to the famous problem of the anomalously slow Gamow-Teller (GT) transitions in the {beta} decay of the A = 14 multiplet is presented. The GT strength distributions to excited states in {sup 14}C and {sup 14}O was studied in high-resolution (d,{sup 2}He) and ({sup 3}He,t) charge-exchange reactions on {sup 14}N. No-core shell-model (NCSM) calculations capable of reproducing the suppression of the {beta} decays predict a selective excitation of J{sup {pi}} = 2{sup +} states. The experimental confirmation represents a validation of the assumptions about the underlying structure of the {sup 14}N ground state wave function. However, the fragmentation of the GT strength over three 2{sup +} final states remains a fundamental issue not explained by the present NCSM using a 6 {h_bar}{omega} model space, suggesting possibly the need to include cluster structure in these light nuclei in a consistent way.