Abstract
The aim of this symposium is to discuss whether synchrotron orbital radiation can be available for use in the mineralogical field, on which Prof. Takeuchi gave a lecture in 1975. Informations about the materials brought out by means of X-rays are reviewed and as a result of it, the need for X-ray sources is made clear . As 'hot' X-ray sources have no room for remarkable improvements, 'cold' X-ray sources such as synchrotron orbital radiation come to be indispensable. The property of synchrotron orbital radiation and the recent research in Photon Factory are discussed.
