A new and promising P2-type layered oxide, Na_5/6[Li_1/4Mn_3/4]O₂ is prepared using a solid-state method. Detailed crystal structures of the sample are analyzed by synchrotron X-ray diffraction combined with high-resolution neutron diffraction. P2-type Na_5/6[Li_1/4Mn_3/4]O₂ consists of two [Li_1/4Mn_3/4]O₂ sheets with partial in-plane √3a × √3a -type Li/Mn ordering. Na/Li ion-exchange in a molten salt results in a phase transition accompanied with glide of [Li_1/4Mn_3/4]O₂ layers without the destruction of in-plane cation ordering. P2-type Na_5/6[Li_1/4Mn_3/4]O₂ translates into an O2-type layered structure with staking faults as the result of ion-exchange. Electrode performance of P2-type Na_5/6[Li_1/4Mn_3/4]O₂ and O2-type Li_x[Li_1/4Mn_3/4]O₂ is examined and compared in Na and Li cells, respectively. Both samples show large reversible capacity, ca. 200 mA h g^–1, after charge to high voltage regardless of the difference in charge carriers.

In condensed-matter physics, spinel-type oxide metal LiV₂O₄ has attracted much attention for recent two decades, thanks to the combination of frustration and extremely heavy electron. Here we feature the making with findings of the entitled paper studying this material. Our preliminary single-crystal neutron study and published powder study are introduced with this point of view. The characteristic form factors to demarcate a metal from an insulator are also discussed.

In the Japanese Spallation Neutron Source (JSNS) of Japanese Proton Accelerator Research Complex (J-PARC), the proton beam with a high power of 1 MW was successfully introduced to the mercury target. In 2015, the beam operation with the power of 500 kW has started. As increasing the beam power, the pitting damage to the target vessel becomes serious. To mitigate the damage, reduction of the peak current density at the target is important for high power beam operation. In order to reduce the peak current density, a beam flattening system with non-linear beam optics using octupole magnets has been developed. It was found that a considerably flat distribution could be obtained with the octupole magnets. The calculated beam profile showed good agreement with the experimental result for 0.8 MW. The peak current density can be reduced as much as 30 %, which mitigates 76 % of the pitting damage at the vessel of the target.

We introduce the basic principle of neutron radiography technique, and the brief review of its applications. Most of works in this article have been performed at TNRF, Tokai, Japan. Neutron radiography is a nondestructive testing method, so that this technique is used for not only academic studies but also industrial applications.

In neutron scattering facilities, it is important to provide a wide range of state-of-the-art sample environment equipment for cutting-edge outputs on the academic and industrial research front. In the Materials and Life Science Experimental Facility (MLF) of J-PARC, a sample environment team has been officially organized with succeeding the previous ad hoc sample environment team, aiming to comprehensively measure safety of the sample environment in the MLF and to perform efficient user support in sample environment. In the MLF, each beamline (BL) has its own dedicated sample environment equipment, while some additional BL-common sample environment equipment is prepared by the sample environment team. MLF users can also bring their own equipment or devices for their experiment. All equipment and devices are required to pass a rigorous safety examination before being allowed in the MLF.