Calorimetric measurements of laser radiation energy balance in spherical targets heated in the Delfin-1 facility

Investigations were made of the energy balance, anisotropy of plasma expansion, and laser radiation scattering on spherical targets heated in the Delfin-1 facility at energies of 0.1–1 kJ incident on the target. The efficiency of the absorption of laser radiation by high aspect-ratio targets of diameter 300 μ or more was 40–45% for a surface power density of (0.1–1)×10¹⁴ W/cm². A correlation was observed between the uniformity of irradiation of the target, the homogeneity of heating, and the anisotropy of plasma expansion.