RIKEN Nishina Center

Hour-scale response of low-Earth-orbit satellite altitude to extreme geomagnetic storms revealed by the NinjaSat CubeSat during the 2024 solar maximum

Abstract Extreme geomagnetic storms accelerate low-Earth-orbit satellite decay by inflating the thermosphere, yet the hour-scale pathway from solar-wind energy to atmospheric heating is poorly understood. Using the GNSS receiver of the NinjaSat CubeSat ( $$\sim 500$$ km, $$97^\ci...

Weak Ferromagnetism in NiS 2 under Nanocrystallization

Structurally well-ordered NiS 2 nanocrystals with an average diameter of 27.0 ± 6.5 nm retain the bulk-like two-step antiferromagnetic transitions, as shown by magnetization and heat-capacity measurements. Below the lower transition, the nanocrystals exhibit a hysteretic ferromag...

The first four ground-level enhancements in the 1940s: investigation, digitization and analysis of forgotten data

Intense solar eruptions occasionally accelerate solar energetic particles (SEPs) and trigger ground-level enhancements (GLEs). Among the 77 known GLEs, the first four #1- 4, in the 1940s, took place before the advent of the standard neutron monitors (NMs) and were missing from th...

Characterization of the GARIS-III Separator via the 40 Ar + 208 Pb Fusion Evaporation Reaction

This work reports on the measurements performed during the commissioning of the GARIS-III separator in RIKEN with the study of the 40 Ar + 208 Pb → 248 Fm * reaction. The excitation functions of the 2n, 3n, and 4n exit channels were measured with maximum cross sections of 27.5 ±...

Codebase release 0.5 for FewBodyToolkit.jl

Few-body physics explores quantum systems of a small number of particles, bridging the gap between single-particle and many-body regimes. To provide an accessible tool for such studies, we present FewBodyToolkit.jl, a Julia package for quantum few-body simulations. The package su...

FewBodyToolkit.jl: A Julia package for solving quantum few-body problems

Few-body physics explores quantum systems of a small number of particles, bridging the gap between single-particle and many-body regimes. To provide an accessible tool for such studies, we present FewBodyToolkit.jl, a Julia package for quantum few-body simulations. The package su...

Therapeutic Efficacy and Safety of Intraperitoneally Administered 211At-Labeled Gold Nanoparticles for Peritoneally Disseminated Malignancies

Background/Objectives: Peritoneal dissemination of malignancies leads to poor prognoses, and no effective treatment currently exists. The difficulty of treating such malignancies is likely because systemically administered drugs cannot easily target malignant cells in the abdomin...

99Mo production cycle based on muon nuclear-capture reaction with infinite 99Tc resources.

Tc resource (Product Catalog; Ando and Takano, 1999; Oigawa, 2014), and the advantages of using muon nuclear-capture reactions for radioisotope production.

An orbifold framework for classifying layer groups with an application to knitted fabrics

Abstract Entangled structures, such as textiles and architected materials, are often doubly periodic. Owing to this property and their finite transverse thickness, the symmetries of these materials are described by the crystallographic layer groups. While orbifold notation provid...

Concurrence in Neutron–Proton Scattering for Polarization-Induced Mixed States

We investigate spin entanglement generated in neutron–proton scattering by evaluating the concurrence from the scattered two-nucleon density matrix. While previous studies mainly discussed pure initial spin states, the present work extends the analysis to polarization-induced mix...