Calculation of the symmetry of irradiation of a spherical laser target allowing for absorption and refraction of radiation in the corona

An analysis is made of a model describing the angular distribution of laser radiation absorbed in a spherically symmetric plasma corona subject to an allowance for refraction. The evolution of this angular distribution during compression of a target is studied assuming the experimental conditions in the Del'fin facility. It is shown that the degree of homogeneity of the heating changes during compression of the target and that the maxima and minima of the distribution function may become displaced. In the case of irradiation conditions satisfying the symmetry of a cube the degree of homogeneity of the absorbed energy is 0.79, whereas under the experimental conditions it is 0.30.