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 shown that contrary to the case of central spark ignition, neutrons effectively heat the plasma in the ignition phase and reduce the threshold temperature for ignition. In practically-interesting regions where the areal density of compressed targets <15 g/cm2, this positive effect exceeds the negative one, i.e. a shortening of the confinement time due to excessive heating in the burn phase. Moreover, the suprathermal fusion reactions induced by neutron recoils appreciably contribute to the energy production. Thus, in the volume ignition scheme, the inclusion of neutronic processes results in lowering the ignition temperature and increasing the maximum fuel gain.