The role of vacuum technology in plasma confinement research and fusion reactor development

The role of vacuum technology in plasma confinement research and in fusion reactor development is briefly reviewed and discussed. Various wall materials and surface conditioning techniques have been developed since 1970's to solve the impurity and density control problems for pulse-operated plasma confinement devices.These works bring about a new domain in the vacuum technology. Although some special vacuum components and techniques have been applied to practical uses in the construction phase of large tokamak devices, the improved vacuum technology for heavier load operation is still needed to realize a steady-state fusion reactor. (author)