日本の静電加速器の歴史を述べるためには，この分野の先進国である欧米における静電加速器の歴史を知っておく必要がある．そのため先ず第1部でその発達の経過，特に大型静電加速器の技術について纏めを行う．第2部で日本における静電加速器の設置状況と静電加速技術の研究の経過を概説する．

Positron Emission Tomography (PET) is a medical diagnosis device using radioisotopes. PET is useful to diagnose cancer, heart and dementia diseases and the number of PET centers is now increasing in Japan owing to the application of insurance cover to cancer disease. The fundamentals of PET and its applications are briefly presented here.

Octupole magnet takes an important part in the cure of the transverse instability at the Photon Factory storage ring. Under the existence of the octupole field, remarkable asymmetric frequency-response curves were observed in the excitation of the vertical betatron oscillation. The form of the response curve depended on the octupole current and the direction of the frequency scan. The betatron resonance continued much above the betatron tune and the amplitude of the oscillation suddenly fall down at the end. The frequency response extended to about 20 kHz higher than the tune frequency when the maximum octupole field was applied. Such asymmetric frequency responses appeared only for the positive frequency scan. We have found that the observed frequency response for the betatron oscillation has many similarities with the frequency response of the nonlinear forced oscillation described by the Duffing equation.

I have been working and living in Japan for a little over 10 years now. I first came over as a graduate student, to work on SuperKamiokande, then started working at KEK as a JSPS fellow after graduating, and now work in the Accelerator Division at KEK. My experiences have varied much over that time, due to different locations and different types of job, but as I look back on my first ten years in Japan, I think I can say that the experiences have been (almost) all positive.

Role of accelerator education at university and its requirements are considered based on my own experience of accelerator research. It is important to make such an environment where students can exhibit their initiative compromising the entire system of the accelerator. Ultimate goal of such an education is to enable students to enjoy their research works.

KEK–CERN cooperation on the LHC accelerator and detector superconducting magnet development is reviewed as well as on the Japanese industrial contribution to the accelerator construction.