Numerical simulation of three-dimensional X-ray and laser field inhomogeneities in experiments with spherical box converters on the Iskra-5 facility

The results of spectral calculations of the dynamics of laser radiation absorption and X-ray generation in a spherical box converter are presented for experiments on inertial fusion performed in the 1990s on the Iskra-5 facility. Numerical simulations were carried out taking into account the actual configuration of 12 laser beams and six apertures for introducing laser radiation. Calculations were performed in the sector approximation in which the inner surface of the box is divided into a certain number of regions or sectors. The movement of matter and radiation transport in each sector were calculated by using the one-dimensional spectral nonequilibrium dynamics program. Spectral calculations showed a strong inhomogeneity of irradiation of a capsule in the M-band region (2.7—2.9 keV). It is shown that the spectrum-averaged root-mean-square inhomogeneity of the X-ray energy flux on the capsule (during the time of its compression) is about 2.5% for laser beams of the same energy and is about 3% if the characteristic energy misbalance between the beams is taken into account.