Time-Resolved XUV Opacity Measurements of Warm Dense Aluminum
Artikel i vetenskaplig tidskrift, 2020

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. Here we 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 temperature-dependent 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.

Författare

S. M. Vinko

University of Oxford

V. Vozda

Czech Academy of Sciences

Charles Univ Prague

Jakob Andreasson

Czech Academy of Sciences

Chalmers, Fysik, Kondenserade materiens fysik

S. Bajt

Deutsches Elektronen-Synchrotron (DESY)

J. Bielecki

European XFEL

T. Burian

Czech Academy of Sciences

J. Chalupsky

Czech Academy of Sciences

O. Ciricosta

University of Oxford

M. P. Desjarlais

Sandia Natl Labs, Pulsed Power Sci Ctr, POB 5800

H. Fleckenstein

Deutsches Elektronen-Synchrotron (DESY)

J. Hajdu

Uppsala universitet

Czech Academy of Sciences

V Hajkova

Czech Academy of Sciences

P. Hollebon

University of Oxford

L. Juha

Czech Academy of Sciences

M. F. Kasim

University of Oxford

E. E. McBride

SLAC Natl Accelerator Lab

K. Muehlig

Uppsala universitet

T. R. Preston

European XFEL

D. S. Rackstraw

University of Oxford

S. Roling

Universität Münster

S. Toleikis

Deutsches Elektronen-Synchrotron (DESY)

J. S. Wark

University of Oxford

H. Zacharias

Universität Münster

Physical Review Letters

0031-9007 (ISSN) 1079-7114 (eISSN)

Vol. 124 22 225002

Ämneskategorier

Atom- och molekylfysik och optik

Fusion, plasma och rymdfysik

DOI

10.1103/PhysRevLett.124.225002

Mer information

Senast uppdaterat

2020-07-01