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

V.I. Annenkov; S.A. Bel'kov; A.V. Bessarab; S.V. Bondarenko; R.V. Garanin; G.G. Kochemasov; V.P. Kovalenko; A.V. Pinegin; N.A. Suslov; N.V. Zhidkov

doi:doi:10.1051/jp4:2006133189

Issue		J. Phys. IV France Volume 133, June 2006


Page(s)		939 - 941
DOI		https://doi.org/10.1051/jp4:2006133189
Published online		16 June 2006

Inertial Fusion Sciences and Applications 2005
J.-C. Gauthier, et al.
J. Phys. IV France 133 (2006) 939-941
DOI: 10.1051/jp4:2006133189

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

V.I. Annenkov, S.A. Bel'kov, A.V. Bessarab, S.V. Bondarenko, R.V. Garanin, G.G. Kochemasov, V.P. Kovalenko, A.V. Pinegin, N.A. Suslov and N.V. Zhidkov

Russian Federal Nuclear Centre - VNIIEF, 607190 Sarov, Russia

Abstract
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) $\cdot$ 10¹³ W/cm² 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 10¹⁴-10¹⁵ W/cm². Probe x-rays were registered by a Bragg spectrometer with spatial resolution. Comparison between experimental data and simulations is discussed.