Looking back the history of IMSS
 
      The Institute of Materials Structure Science (IMSS) was founded in April 1997 combining former Photon Factory (PF), Neutron Facility (KENS), both of KEK, and former Meson Science Laboratory (MSL) of the University of Tokyo. I have served as the director of this new institute for six years till the end of last March. Now let me examine to what extent my contemplation to develop the research activity of the institute was materialized in my director period.

   Major plans that I initially proposed are summarized as follows.

1.	Implement large-scale instrumental upgrade of the two existing light source facilities, PF and PF-AR, to make them competitive with the third generation sources.
2.	Secure budget for the construction of a high intensity proton accelerator to revitalize over 20 years old KENS and MSL and make them one of the most advanced facilities in the world.
3.	Organize strong research teams in a few promising fields and support their activity by assigning highest research priority.

      As for the light source upgrade plans, we realized a very successful improvement over the 6.5 GeV PF-AR facility. It included replacement of the whole accelerator vacuum system and construction of a new experimental hall. To my regret the plan to introduce a number of additional straight-sections for insertion devices into the 2.5 GeV PF-ring has not been realized yet.

      In 2001, the future plan for KENS and MSL came off as a high intensity proton accelerator complex, the J-PARC project by a joint effort between KEK and JAERI. The complex includes a 3 GeV rapid cycling synchrotron with a design beam power of 1 MW to provide world highest intensity neutron and muon beams to the facilities.

      We selected research fields of structural solid state physics and structural biology to be given high priorities. A research program was launched to pursue the structural solid state physics in collaboration with four outside groups tightly connected to KEK experimental facility through a computer network (so called co-laboratories). We could raise a powerful structural biology group and make their laboratory to be one of the leading structural biology research center in Japan.

      Importance of particle accelerators is getting more recognition in advanced research fields of materials and life sciences. I feel I made a certain contribution to furthering this scientific development as the IMSS director.

The author of this article, Dr. Yoshitaka KIMURA, the former director of IMSS is actively participating in J-PARC project, helping young accelerator researchers. He retired from KEK last April.