Stability of compression of shell targets in the Progress facility

The six-beam Progress laser facility was used in a study of compression and heating of glass microbubbles filled with a DT gas and coated outside by a thin (~0.1μ) aluminum film. The power density of Nd laser radiation (λ=1.054μ) reaching the target surface was (1–2)×10¹⁵ W/cm² and the specific energy deposited in the target was 0.1-0.25 J/ng. Two-dimensional images of a laser plasma were recorded using x-ray lines of multiply charged Si and Al ions. Strong Al lines observed at distances close to the target center were evidence of a strongly unstable nature of compression of the laser plasma. This was confirmed also by a weak dependence of the neutron yield on the specific input energy, which did not agree with the results of one-dimensional calculations carried out using the Zarya program.