The transport system of intense light ion beams through plasma channels is considered in the reactor system. Channel parameters for the beam transport are determined by diode brightness, pellet requirements, and channel constraints. We considered the desirable reactor parameters and the transportable power window. We have studied most of the single‐channel formation by the laser initiation, the beam transport in this channel, and the multiple‐channel formation within this window. Uniform and stable plasma channels were formed in 10–40 Torr of ethylene gas by the guidance of the CO2 laser with up to 1‐m length. Ion beams were injected to this channel from a pinch‐reflex ion diode on the Reiden IV generator. High total transport efficiencies of up to 70% were achieved. Beam orbits, estimated from the post‐transported beam pattern on the detector film with energy resolution, were in good agreement with the calculation in the center current mode. We proposed the uniform irradiation reactor channel system using the dodecahedral arrangement so as to satisfy the transportable window constraints. A triple plasma channel was also formed as a simulational model of an overlap channel system. A desirable channel system is expected from experiments and calculations when channels and return paths are alternately arranged.