Very Large Hadron Collider R&D

This article discusses the present state of R&D for a post-LHC very large hadron collider (VLHC). Such a machine can be built with today's technology; the thrust of the R&D is to reduce the cost of the machine, through development of new ideas and utilization of new technologies. R&D issues in the areas of accelerator physics, magnets, and general accelerator technologies, will be reviewed. Finally, the outlook for future R&D will be presented. (35 refs).