Abstract
The fast ignition concept is attractive because a high gain is achieved by small laser energy. Based on fast ignition targets the design windows of laser fusion modular power plants, which have several reactors with 100 ~ 200 MJ fusion pulse energies, and with 100 ~ 240 MWe electric powers, are analyzed. The feasibilities of a small-sized laser fusion experimental reactor suitable for developing their practical power plants are discussed. A road map for laser fusion energy and a new concept of a small-sized fast ignition experimental reactor are proposed.