[en] The neutronics in the blankets to be used for particle beam (LIB or HIB)-driven ICF reactors were examined in case of the spherical reactor vessels with dry wall reactor cavities. The calculations were performed with the one-dimensional neutron transport code ANISN-JR and the nuclear data GICX 40. To examine the scale merits or demerits of particle beam ICF reactor systems, three reactor cavities were designed. The inner radii of the cavities were 2.0, 5.0 and 15.0 m, and the fusion energy of each cavity is designed to be 30 MJ, 300 MJ or 3000 MJ. Two types of the blankets for the dry wall reactors were examined. In one blanket (A-type blanket), a 64 cm thick liquid Li layer was the first blanket zone. In another blanket (B-type blanket), there was a moderator made of graphite behind the first wall, and then the second SUS wall and a 64 cm thick Li layer existed. There were reflectors made of graphite outside the Li blankets in both types. The thermal deposition in the first wall in the A blanket was quite larger than that in the B blanket. The tritium breeding ratio was less than unity in the B-type blanket. The first wall (SUS 1) reduced the number of 14 MeV neutrons, and softened the neutron energy spectrum. (Kato, T.)