About the correction of laser beams with phase front vortex

The earlier predicted failure of phase conjugation at the stimulated Brillouin scattering (SBS) of the vortex laser beam directly focused into the SBS medium is experimentally confirmed. Phase conjugation of the vortex beam can be realized with using an advanced SBS mirror

Measurements of X-ray spectral opacity of dense plasma at ISKRA-5 laser facility

Powerful iodine ISKRA-5 laser facility was upgraded and now operates on the second harmonic. Experiments were performed to measure the x-ray spectral opacity of dense plasma of different materials. Sample of material under study was fabricated as a thin plate with the 0.1-0.15 $\mu$m thickness and was heated by the soft x-rays generated by irradiation of a thin film gold converter by one beam of the ISKRA-5 laser facility. Typical laser intensity on the converter was (1-5)$\cdot$10$^{13}$ W/cm$^{2}$ and laser pulse duration was 0.5-0.6 ns. The effective temperature of sample under experimental conditions didn't exceed 30-40 eV. The sample was tampered by $\sim$ 1 $\mu$m plastic layers on both sides to avoid its rarefaction during heating and to obtain a quasistationary layer of a dense plasma prepared to be probed by a backlighter. The backlighter was aluminum or dysprosium film irradiated by another beam of the ISKRA-5 laser facility with an intensity of 10$^{14}$-10$^{15}$ W/cm$^{2}$. Probe x-rays were registered by a Bragg spectrometer with spatial resolution. Comparison between experimental data and simulations is discussed