Intense pulsed neutron sources open a new window of mineralogy

Recently mineral scientists have paid attention to the neutron scattering, because some intense pulsed neutron sources have been constructed or in planning in the world. In Japan, the High Energy Accelerator Research Organization (KEK) and the Japan Atomic Energy Research Institute (JAERI) have jointly constructed a 1 MW pulsed neutron source (JSNS) at Tokai, Ibaraki. The neutron and the x-ray diffraction should provide complementary information each other because of their physical properties. For example, light elements like hydrogen are almost invisible for x-ray and it is difficult for x-ray to distinguish neighboring elements in the Periodic Table such as Mg, Al and Si, which are major elements in geological materials and often show interesting order-disorder relating phenomena. However, neutron expects to provide useful information about those invisible problems of x-ray since the scattering cross-section of neutron is independent of the atomic numbers. In this paper, we will give an overview of elastic neutron scattering and give some ideas of mineral physics at high pressure and high temperature. In addition, we will shortly introduce the JSNS and our proposal of a high pressure/temperature material science station in the JSNS. (author)