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Ryo Taniuchi

Publications and source records attributed to Ryo Taniuchi.

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Detectors for next-generation quasi-free scattering experiments at the RIBF

The advent of high-intensity radioactive ion beams has opened new avenues for nuclear structure research. By studying exotic ions, phenomena such as shell evolution, halos, and the limits of stability have been studied. In particular, Quasi-Free Scattering (QFS) experiments on hydrogen targets have proven to be a valuable tool to investigate the structure of exotic ions. Recently, a series of QFS experiments were performed at the Radioactive Isotope Beam Factory (RIBF) of the RIKEN Nishina Center employing the MINOS liquid hydrogen system. A fundamental part of the success of these experiments was the use of dedicated devices to measure the gamma-rays, charged particles, and neutrons emitted in the reactions. The experience gained during the past campaigns, as well as the upcoming upgrade of the RIBF facility call for improvements on the existing devices, as well as for the development of new detection systems. Here we review the main detection devices used at the RIBF for QFS experiments, and give an overview of the ongoing and upcoming developments.

physics.ins-det

Competition of the shell closure and deformations across the doubly magic $^{78}$Ni

The properties of the neutron-rich isotope $^{78}$Ni, long postulated to be doubly magic, have been extensively explored through recent experimental and theoretical studies. Confirmations of robust shell closures at $Z=28$ and $N=50$ as well as hints of competing deformations in neighboring isotopes have been obtained. Innovations of a thick liquid hydrogen target system with vertex reconstructions and the in-beam $\gamma$-ray spectroscopy technique have facilitated detailed investigations into the nuclear structure of these extreme systems. Proton knockout reactions conducted at relativistic energies have provided the first experimental evidence of shape coexistence at the cornerstone nucleus $^{78}$Ni and its vicinity. As the nuclear structure around $^{78}$Ni influences the description of very neutron-rich systems and r-process nucleosynthesis, these findings underscore the importance of further investigations. This review encapsulates the recent results concerning the nuclear structure at the vicinity of $^{78}$Ni on both experimental and theoretical aspects. It outlines prospective research directions that could further illuminate this complex and intriguing area of the nuclear chart.

nucl-ex