material used to reduce neutron energy by scattering without appreciable capture, a material, such as ordinary water, heavy water, or graphite, that is used in a reactor to slow down high-velocity neutrons, thus increasing the likelihood of fission, materjal, mida kasutatkse neutronite aeglustamiseks läbi neutronite põrkumise materjaliga ilma olulise neutronite neeldumiseta

a material used to reduce, by scattering collisions and without appreciable capture, the kinetic energy of neutrons, material such as water, heavy water, graphite used to slow down neutrons in a reactor