Time-resolved XUV opacity measurements of warm dense aluminum

0533553 - FZÚ 2021 RIV US eng J - Journal Article
Vinko, S.M. - Vozda, Vojtěch - Andreasson, Jakob - Bajt, S. - Bielecki, J. - Burian, Tomáš - Chalupský, Jaromír - Ciricosta, O. - Desjarlais, M.P. - Fleckenstein, H. - Hajdu, Janos - Hájková, Věra - Hollebon, P. - Juha, Libor - Kasim, M.F. - McBride, E.E. - Muehlig, K. - Preston, T.R. - Rackstraw, D.S. - Roling, S. - Toleikis, S. - Wark, J. S. - Zacharias, H.
Time-resolved XUV opacity measurements of warm dense aluminum.
Physical Review Letters. Roč. 124, č. 22 (2020), s. 1-6, č. článku 225002. ISSN 0031-9007. E-ISSN 1079-7114
R&D Projects: GA MŠMT EF16_019/0000789; GA MŠMT EF15_003/0000447
EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE
Grant - others:OP VVV - ADONIS(XE) CZ.02.1.01/0.0/0.0/16_019/0000789; OP VVV - ELIBIO(XE) CZ.02.1.01/0.0/0.0/15_003/0000447
Institutional support: RVO:68378271
Keywords : inverse-bremsstrahlung absorption * free-electron laser * free-free opacity in plasma * time-resolved XUV opacity measurements * warm dense Aluminium plasma
OECD category: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)
Impact factor: 9.161, year: 2020
Method of publishing: Limited access
https://doi.org/10.1103/PhysRevLett.124.225002

The free-free opacity in plasmas is fundamental to our understanding of energy transport in stellar interiors and for inertial confinement fusion research. However, theoretical predictions in the challenging dense plasma regime are conflicting and there is a dearth of accurate experimental data to allow for direct model validation. Herewe present time-resolved transmission measurements in solid-density Al heated by an XUV free-electron laser. We use a novel functional optimization approach to extract the temperaturedependent absorption coefficient directly from an oversampled pool of single-shot measurements, and find a pronounced enhancement of the opacity as the plasma is heated to temperatures of order of the Fermi energy. Plasma heating and opacity enhancement are observed on ultrafast timescales, within the duration of the femtosecond XUV pulse. We attribute further rises in the opacity on ps timescales to melt and the formation of warm dense matter.
Permanent Link: http://hdl.handle.net/11104/0311917