Open AccessMechanism of single-shot damage of Ru thin films irradiated by femtosecond extreme UV free-electron laser
Author(s) -
Igor Milov,
Igor A. Makhotkin,
R. Sobierajski,
Nikita Medvedev,
Vladimir Lipp,
J. Chalupský,
Jacobus Marinus Sturm,
K. Tiedtke,
Gosse de Vries,
M. Störmer,
Frank Siewert,
R. W. E. van de Kruijs,
Eric Louis,
Iwanna Jacyna,
M. Jurek,
L. Juha,
V. Hájková,
Vojtěch Vozda,
T. Burian,
Karel Saksl,
B. Faatz,
Barbara Keitel,
Elke Plönjes,
S. Schreiber,
S. Toleikis,
R.A. Loch,
Martin Hermann,
Sebastian Strobel,
Han-Kwang Nienhuys,
Grzegorz Gwalt,
Tobias Mey,
H. Enkisch,
F. Bijkerk
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.019665
Subject(s) - femtosecond , extreme ultraviolet , laser , spallation , materials science , optics , irradiation , ultrashort pulse , electron , radiation damage , optoelectronics , radiation , physics , neutron , quantum mechanics , nuclear physics
Ruthenium is a perspective material to be used for XUV mirrors at free-electron laser facilities. Yet, it is still poorly studied in the context of ultrafast laser-matter interaction. In this work, we present single-shot damage studies of thin Ru films irradiated by femtosecond XUV free-electron laser pulses at FLASH. Ex-situ analysis of the damaged spots, performed by different types of microscopy, shows that the weakest detected damage is surface roughening. For higher fluences we observe ablation of Ru. Combined simulations using Monte-Carlo code XCASCADE(3D) and the two-temperature model reveal that the damage mechanism is photomechanical spallation, similar to the case of irradiating the target with optical lasers. The analogy with the optical damage studies enables us to explain the observed damage morphologies.