Neutronic effects in reactor-size ICF targets

On the basis of coupled transport-hydrodynamic calculations, the neutronic effects in reactor-size volume ignition targets are investigated. It is sho wn that contrary to the case of central spark ignition, neutrons effectivel y heat the plasma in the ignition phase and reduce the threshold temperatur e for ignition. In practically-interesting regions where the areal density of compressed targets <15 g/cm(2), this positive effect exceeds the negativ e one, i.e. a shortening of the confinement time due to excessive heating i n the burn phase. Moreover, the suprathermal fusion reactions induced by ne utron recoils appreciably contribute to the energy production. Thus, in the volume ignition scheme, the inclusion of neutronic processes results in lo wering the ignition temperature and increasing the maximum fuel gain. (C) 1 999 Elsevier Science S.A. All rights reserved.