Review of Advanced Accelerator Concepts R & D in Japan

More than 15 Japanese laboratories are dedicated to the advanced and compact accelerator development. Some use ultra‐intense lasers and others use microwave concepts. As for the laser electron accleration, the topics are the capillary acceleration and the mono‐energetic acceleration. The laser ion acceleration is also active. As well, the compatization is proceeding of the current rf accelerator. The National Institute for Radiological Science is promoting an advanced accelerator concept project mainly for the medical application.