Eur. Phys. J. D (2013) 67: 136
https://doi.org/10.1140/epjd/e2013-30630-8

Regular Article

A new target design for laser shock-compression studies of carbon reflectivity in the megabar regime

¹ Dipartimento di Fisica G.Occhialini, Università di Milano Bicocca, Piazza della Scienza 3, 20126 Milan, Italy
² University Bordeaux, CEA, CNRS, CELIA (Centre Laser Intense at Applications), UMR 5107, 33405 Talence, France
³ Laboratoire pour l’Utilisation des Lasers Intenses, UMR 7605 CNRS-CEA-ÉcolePolytechnique-Paris VI, Palaiseau, France
⁴ Institute of Laser Engineering, Osaka University, 2–6 Yamadaoka, Suita City, Osaka 565-0871, Japan
⁵ Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milan, Italy
⁶ INFN-Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati, Italy
⁷ Institute of Advanced Technologies - Palazzo Presidenza Provincia, Via Garibaldi, 91100, Trapani, Italy
⁸ Institute for Geothermal Researches DSC of Russian Academy of Sciences - Pr. Shamilya 39A, 367030 Makhachkala, Russia

^a e-mail: batani@mib.infn.it

Received: 12 October 2012
Received in final form: 26 February 2013
Published online: 11 July 2013

Abstract

A new design for targets employed in laser induced shock-compression experiments is presented. Numerical simulations to optimize target parameters and to clarify shock dynamics are realized. The experiments proved the new scheme is reliable and appropriate for reflectivity measurements of thermodynamical states lying out of the standard graphite or diamond Hugoniot: the final state reached in compression can be varied tuning the carbon layer characteristics (initial density and thickness) and the laser intensity, with the possibility to determine the reflectivity of carbon and the position on the phase diagram. An increase of reflectivity in carbon has been observed at 260 GPa and 14 000 K while no increase in reflectivity is found at 200 GPa and 20 000 K.