[en] A newly developed one-dimensional hydrodynamic code ''Mt. FUJI'' is used to simulate the implosion motion of a hollow shell target. The code includes special processes occurring in the target such as fuel depletion caused by fusion reactions and reabsorption of neutrons, α-particles and photons which are produced in the target, as well as the ordinary processes, for instance, depositions of energy, momentum and mass of impinging light ion beams. The simulation shows that a pellet gain of more than 90 can be attainable in an adiabatic compression of the fuel provided that the pellet has the optimum amount of D-T fuel and the fuel velocity exceeds 10⁷ cm/sec at the pellet implosion. (author)