In this article studied was the temporal development of radiation damage in the first wall by fusion α-particles. By means of computer simulation program MARLOWE-13 with the time-ordered binary approximation

the radiation damage in amorphous iron materials caused by fusion α-particles with energies in the order of ten’s keV has been investigated. The time evolution of the distributions of vacancies

energy deposition and stopped α-particles in the materials have been calculated. The results based on the time-ordered and velocity-ordered collision cascade simulations has also been compared.