Recently, much attention has been paid to inertial-confinement fusion (ICF) by an intense pulsed light-ion beam (LIB). In this paper, the focusing and the transport of the LIB, that are believed to be most important themes in these fields of interests, are to be reviewed, from which particular points of the problems to be solved in the near future will be made clear.
In this short comments, we hope to point out the misunderstanding that Heliotron device is a near conductor system, which was suggested by Prof. T. Uchida in Kakuyugo Kenkyu 48 Supplement 1, p. 1 (1982). Heliotron device is thought to be one of the most important alternatives of tokamak device. We discuss about the necessity of the helical conductor and its basic physical meaning, which require a strong current.