We report the results of neutron scattering and nuclear magnetic resonance (NMR) measurements on the two-dimensional quantum spin system SrCu2(B03)2. The dispersion curve of the first excited state obtained by inelastic neutron scattering is almost flat. The Cu-NMR spectrum splits into four lines by the nuclear spin-spin coupling mediated by the electron spins of Cu ions which form dimers. These results are evidences of the characteristics suggested by theoretical studies. The Cu spectrum at 27.6, where the 1/8 plateau is observed in the magnetization curve, has a large number of peaks distributed over a wide frequency range. By comparing the NMR and theoretical results, the spin structure of the 1/8 plateau phase is determined. These results are good examples of the cooperative study by neutron scattering and NMR.
Neutron radiography (NR) technique has been applied to the diffusion coefficien measurements of lithium ions in ion conductive solids using 7Li/6 Listable isotopes as tracer. In this article, we present the procedure of diffusion coefficient measurement by means of NR method, and reviewed the results of three types of lithium ion conductors, i.e. Li4/3Ti5/3O4, LISICON solid solutions, and perovskite-type lithium ion conductors, including analyses of diffusion mechanisms.
A new neutron reflectometer “SUIREN” will provide beam-time for general users from the 5th cycle of the JRR-3 operation schedule in 2006. SUIREN has been under construction at the C2-2 port of the JRR-3 guide hall. Test measurements have been carried out since this April and proved that SUIREN can provide reflectivity data less than 10-6. This article describes the status of the construction, results of test measurements and future plans.
The neutron flux and energy spectrum from the renewed cold neutron source was measured at the C2-1 beam port in the guide hall of JRR-3. We confirmed that both the absolute flux of 2×1012n/m2s and the shape of energy spectrum were reproduced after the replacement of the liquid hydrogen tank. JAEA has a plan to increase cold neutron flux ten times as strong as that at present by introducing a new type of hydrogen tank and super mirror neutron guide in the next term.