J. Nakano

Fusion and breakup at the barrier with 11Be

Abstract The cross-section excitation functions for various neutron-evaporation channels have been measured in the 11,10,9 Be+ 209 Bi systems around the Coulomb barrier, for energies ranging from 35 to 70 MeV, in order to see any eventual effect from the expected breakup of the 11 Be unstable halo nucleus. Within the simplified reaction process considered, the data are consistent with a breakup of 11 Be at the top of the Coulomb barrier contributing to less than 25% to the total fusion cross-section; however contributions from other type of breakup mechanisms cannot be excluded.

Multiple-sampling and tracking proportional chamber for nuclear reactions with low-energy radioactive isotope beams

Abstract Nuclear reactions with radioactive isotope beams at low energy near to the Coulomb barrier are very important for studying nuclear astrophysics, nuclear structure and the reaction mechanism involving unstable nuclei. Due to the limited intensity of low-energy radioactive isotope beams, a new device is required to carry out experiments with reasonable statistics. A multiple-sampling and tracking proportional chamber was constructed for measuring these reactions and tested with radioactive isotope beams. In addition, read-out electronics and a data-acquisition system were developed and tested along with the detector. It was proved that they are useful for detecting nuclear reactions in the low-energy region, like a fusion reaction and astrophysical nuclear reactions.

Implementation of on-site virtual time machine for mobile devices

In this study, we developed a system for mobile devices designed to provide a virtual experience of past scenery depicted in old photographs by superimposing them on landscapes in video see-through frames. A user is asked to capture a photograph of a landscape to be used as a keyframe and enter correspondence points between the new and old photos. The old photograph is deformed by projective transform with homography computed based on correspondence points. We then superimpose of the old photograph onto video see-through frames of current landscape. To achieve real-time and robust superimposition on mobile devices, both motion-sensor-based pose information and camera-image-keypoint-tracking-based pose information is used for devices camera pose tracking.

Measurement of fusion cross section with neutron halo nuclei

Abstract Fusion cross sections of 11 Be, 10 Be and 9 Be have been measured on 209 Bi target at 30–70 MeV. Due to the neutron halo effect of 11 Be, a large enhancement or suppression of the fusion cross section around the Coulomb barrier was theoretically predicted. Comparing the excitation function of 11 Be with 10 Be at near the Coulomb barrier region, no significant difference has been observed.

Structure of Λ13C hypernucleus studied by the (K−, π−γ) reaction

Abstract The BNL-AGS/E929 experiment was carried out to study energy levels of the Λ 13 C hypernucleus by a gamma-ray spectroscopy. Energy splitting of the spin-orbit doublets, 1 2 − and 3 2 − states, was estimated precisely. The excitation energy of the 1st 3 2 + state was also measured. We discuss the symmetric and the anti-symmetric spin-orbit interactions between a Λ particle and a nucleon from the measurement.

13C active target for hypernuclear experiment

Abstract We present the design of a 13C active target used in the (K−,π−) reaction measurement for hypernuclear studies. The active target has been fabricated from enriched 13C benzene by adding commercially available laser dyes. The performance of the active target has been tested with a 930 MeV /c kaon beam, and used for the 13C(K−,π−γ)13ΛC reaction measurement to reduce the K− decay in-flight backgrounds.

Case Study of AR Field Museum for Activating Local Communities

In this research and development, we use virtual reality and Augmented Reality (AR) technology which is experiential media accompanying physicality as social value of space resources (buildings, townships, townscape) with historical and cultural values. It is aimed to communicate to the subjects inside and outside the region by using visualization and experience and further combining with the method of community design to find the possibility of active utilization.

High-Resolution Gamma-Spectroscopy of Λ 7 Li and Λ 9 Be

We report on the first two experiments of hypernuclear γ-ray spectroscopy with Hyperball, a large-acceptance germanium detector system. In a KEK experiment, we observed two γ transitions in Λ 7 Li, the spin- flip M1(3/2+ → 1/2+) at 691.7 ± 0.6 stat ± 1.0 sys keV and the E2(5/2+ → 1/2+) at 2050.4 ± 0.4 stat ± 0.7 sys keV. The former gives unambiguous information on the strength of the ΛN spin-spin interaction. B(E2) of the latter transition was measured to be \( 3.6 \pm {0.5^{stat}}\,_{ - 0.4}^{ + 0.5}{\,^{sys}}{e^2}f{m^4} \). In the second experiment at BNL, we observed the E2(5/2+, 3/2+ → 1/2+) transitions of Λ 9 Be at around 3.05 MeV.

Spin-orbit splitting of 13ΛC

Publisher Summary Since ΛN scattering data are extremely limited due to experimental difficulties, the reaction data have clarified the gross structure of the A-nucleus interaction. The strange quark contributes little to the nuclear force. The small Λ-nucleus spin-orbit interaction has been one of the most interesting subjects in the hypernuclear physics for more than 20 years. The re-analysis of the emulsion experimental data collected by the European K- collaboration also indicates a relatively large splitting. There are also discrepancies among theoretical predictions on the spin-orbit splitting. This chapter performs an experiment with an electromagnetic probe and has great advantages over previous experiments. The (K-, π-) reaction on an enriched 13C target was used at the Brookhaven Alternate Gradient Synchrotron. This experiment with high resolution and high statistics is necessary to conclude the discrepancies.