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The worldwide supply of 99Mo isotopes now encounters a serious crisis due to difficulties in sustainable production by research nuclear reactors. We report the experimental data for the 99mTc and impurity isotopes produced via the natMo(γ, n) reaction with bremsstrahlung γ-rays generated using a 30 MeV electron beam. The supply feasibility of 99mTc isotopes via the natMo(γ, n) reaction is discussed on the basis of the obtained data. [ABSTRACT FROM AUTHOR]

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 of the H( 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 (CD) 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 H( p, p) inclusive breakup reaction at 250 MeV. [ABSTRACT FROM AUTHOR]

For the study of three nucleon force (3NF) effects in the intermediate energy region, the differential cross sections and the vector analyzing power A were measured for the H( p, n) inclusive breakup reaction at 170 MeV. The polarized proton beam of 170 MeV was injected to the deuterated polyethylene (CD) 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 H( p, p) inclusive breakup reaction at 250 MeV. [ABSTRACT FROM AUTHOR]

Tensor correlations in He 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 He 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. [ABSTRACT FROM AUTHOR]

Spectroscopy for neutron-rich nuclei He and Be has been performed by means of heavy-ion double charge exchange (HIDCX) (O, Ne) reaction on stable target nuclei Be and C, respectively. Several clear peaks in Be at low excitation energy region even above neutron separation energy have been observed in one-shot measurement, whereas no prominent signals of He have been observed owing to the small cross section. It is shown that the HIDCX reaction is a new powerful spectroscopic tool for study of unstable neutron-rich nuclei. [ABSTRACT FROM AUTHOR]

The triple α reaction rate in stars is quite important in many astrophysical scenarios including the stellar evolution and carbon synthesis in stars. Recently the non-resonant triple α reaction rate has been reevaluated using a calculation with the continuum-discretized coupled-channels (CDCC) method, which dramatically increased the rate at low temperature compared to the widely-used NACRE compilation. Since the enhancement influences strongly on astrophysical model simulations, we have planned an experiment for drawing conclusion on the non-resonant triple α reaction rate at low temperature by measuring the three- α continuum state in C. We report the present situation of the experiment. [ABSTRACT FROM AUTHOR]

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 for the H( 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. [ABSTRACT FROM AUTHOR]

Gamow–Teller states, possibly with narrow widths, have been searched for by the 4He(3He, 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. [ABSTRACT FROM AUTHOR]

Analyzing powers measurement Ay, Ayy and Axx for the d - p elastic scattering were performed at the Internal Target Station of Nuclotron at JINR at Ed = 880 and 2000 MeV. These data are necessary to obtain the information on the 3NF structure and the relativistic effects. They are also important for development of the efficient deuteron beam polarimetry at high energies. The results of the analyzing powers at Ed = 880 MeV covered the angular range from 60 to 140° in the c.m.s. are compared with several theoretical calculations. The preliminary data on the analyzing powers measurement Ay, Ayy at Ed = 2000 MeV are discussed. [ABSTRACT FROM AUTHOR]

The cluster structures of the excited states in 11B and 13C were discussed by measuring the isoscalar monopole strengths in the inelastic α scattering at Eα = 388 MeV. It was found that the $1/2^-_2$, $1/2^-_3$, and $1/2^-_4$ states in 13C are candidates for the α cluster states with a 3α + n molecular configuration. [ABSTRACT FROM AUTHOR]

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 . 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 state at is well described by the AMD calculation and is an evidence for a developed three-body cluster structure. [Copyright &y& Elsevier]

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.© 2004 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

The triple alpha reaction is one of the most important reactions in the nuclear astrophysics. However, its reaction rate in high temperature environments at T 9 > 2 was still uncertain. One of the major origins of the uncertainty was that the radiative-decay probability of the 3 1 − state in 12C was unknown. In the present work, we have determined the radiative-decay probability of the 3 1 − state to be 1.3 − 1.1 + 1.2 × 10 − 6 by measuring the 1H(12C,12C p) reaction for the first time, and derived the triple alpha reaction rate in high temperature environments from the measured radiative-decay probability. The present result suggests that the 3 1 − state noticeably enhances the triple alpha reaction rate although the contribution from the 3 1 − state had been assumed to be small. [ABSTRACT FROM AUTHOR]

The experimental program on the study of deuteron-proton interaction at Internal Target at Nuclotron is discussed. Recent results on the deuteron vector and tensor analyzing powers in dp-elastic scattering obtained at intermediate energies are presented. The status of the DSS setup upgrade is reported. [ABSTRACT FROM AUTHOR]

In our previous measurement of pd radiative capture at E d = 137 and 196 MeV, we found an interesting fact that the measured tensor analyzing powers show the relation A xx ≈ A yy , although calculated A xx and A yy are apparently different, A xx ≠ A yy . The measured A yy agrees fairly well with the 3 N calculations, and the measured A xx largely disagrees with calculated A xx . Similar experiments on pd capture have been made at KVI at nearly the same energies of 130–180 MeV. The KVI data also support A xx ≈ A yy relation, but absolute values of A xx and A yy at KVI are about half of RCNP data. Therefore, we made a new experiment of pd capture at E d = 196 MeV. A zz was measured in three different ways, and data analysis is in progress. Preliminary data seem to support our previous data. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]

Under the assumption of isospin symmetry, Tz = ±3/2 → ±1/2 Gamow-Teller (GT) transitions in an isobar quartet with a mass A are analogous, where Tz = (1/2)(N -- Z) is the z component of the isospin T. We studied the Tz = +3/2 → +1/2 GT transitions by the 37Cl(3He, t)37Ar reaction at an incoming beam energy of Ebeam = 140 MeV/nucleon with an energy resolution of ΔE = 30 keV. The distribution of the GT strength was obtained up to an excitation energy (Ex) of 14.2 MeV. This distribution was compared with that of the Tz = --2/3 → --1/2 transitions studied in 37Ca β decay up to Ex = 8.6 MeV. Although the overall distributions were similar, details of the fine structure were not necessarily reproduced. The experimental results were compared with a shell-model (SM) calculation using the USD interaction and the effective GT operator that compensates for the effect of limited model space. Although the overall distribution was reproduced by the SM calculation, the fragmentation of states was not reproduced. Neutrino cross sections were derived for the 8B solar-neutrino source. [ABSTRACT FROM AUTHOR]

The double-differential cross sections for the 208Pb and 90Zr(t, 3He) reactions at 300 MeV/u have been measured at the RI Beam Factory at RIKEN. This was the first physics experiment with the SHARAQ magnetic spectrometer. The combined analysis of the present (t,3 He) data and previous (n, p) data provides the clearest identification for the &bgr;+ isovector spin monopole resonance both in the 208T1 and 90Y nuclei, and puts the observations of this giant resonance on a firm foundation. The measured distributions of the (t, 3He) monopole cross sections were well reproduced by the distorted-wave Born approximation calculation, where the target transition density was calculated with the self-consistent Hartree-Fock plus random-phase approximation using the T43 Skyrme interaction. A major part of the expected &bgr;+ isovector spin monopole strength was found in the measured cross section spectra. [ABSTRACT FROM AUTHOR]

The double-differential cross sections for the 116Cd(p,n) and 116Sn(n,p) reactions were measured at 300 MeV for studying the nuclear matrix element of the 116Cd ßß 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 116In are 40 ± 6 and 11 ± 1 in the (p,n) and (n,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. [ABSTRACT FROM AUTHOR]

Measurements of deuteron–proton breakup reactions at 135 MeV/A have been made at RIKEN Accelerator Research Facility, focusing on the specific coplanar configurations. The obtained results are compared with the Faddeev calculations based on the modern nucleon–nucleon forces together with the Tucson-Melbourne99, and UrbanaIX three nucleon forces. [Copyright &y& Elsevier]

The differential cross sections and the vector analyzing powers for the nd elastic scattering at E n = 250 MeV have been measured for the study of the three-nucleon force (3NF) effects in the Coulomb-free system. To cover a wide angular region, the experiments were performed by using two different methods at the (n, p) facility and at the NTOF facility which constructed at the Research Center for Nuclear Physics (RCNP). The results were compared with theoretical predictions of the Faddeev calculations based on the modern nucleon-nucleon (NN) forces with the three-nucleon force (3NF). The inclusion of 3NFs leads to a good description of the cross section except for the backward angles. The results were also compared with the theoretical predictions with relativistic corrections. The direct data-to-data comparison of the cross sections of the nd and pd was performed. [Copyright &y& Elsevier]

The 58Ni(t,3He)58Co reaction at 112 MeV/nucleon was measured to identify strength associated with Gamow-Teller transitions in the direction. The experiment is a test case for future similar studies. The main aim of such studies is to test theoretical models used to predict Gamow-Teller strength distributions that serve as input for supernovae evolution calculations. The results indicate that the (t,3He) reaction is indeed a powerful tool to perform such tests. [Copyright &y& Elsevier]

Background-free inelastic scattering spectra have been obtained for 144,148,150,152,154Sm with 386 MeV α particles at forward angles (including 0°) to investigate the effect of deformation on the isoscalar giant dipole resonance. The strength distributions for isoscalar giant resonances have been extracted via a multipole decomposition analysis using angular distributions calculated in the framework of the density-dependent single-folding model. The effects of deformation are found to be different for the low- and high-excitation energy components of the isoscalar giant dipole resonance. Evidence has been obtained for the theoretically-predicted mixing between the isoscalar giant dipole resonance and the high energy octupole resonance. [Copyright &y& Elsevier]

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. [Copyright &y& Elsevier]

We have designed and constructed a new beam line which can accomplish both lateral and angular dispersion matching with the Grand Raiden spectrometer. In dispersive mode, lateral and angular dispersions of the beam line are b16=37.1 m and b26=−20.0 rad, respectively, to satisfy matching conditions for Grand Raiden. In achromatic mode, the beam line satisfies the double achromatic condition of b16=b26=0. The magnifications of the beam line are (Mx,My)=(−0.98,0.89) and (−1.00,−0.99) for dispersive and achromatic modes, respectively. In the commissioning experiments, we have succeeded to separate the first excited 2+ state of 168Er with Ex=79.8 keV clearly from the ground state in the (p,p′) reaction. We achieved energy resolutions of ΔE=13.0±0.3 and 16.7±0.3 keV in full width at half-maximum for 295 and 392 MeV protons, respectively. These energy resolutions agree with the resolving power of Grand Raiden for an object size of about 1 mm. [Copyright &y& Elsevier]