Laser-matter Interaction
and Chemical Physics
Libor Juha
Department of Radiation and Chemical Physics
Institute of Physics
Academy of Sciences of the Czech Republic
Prague, Czech Republic
E-mail: [email protected]
Main research topics:
(a) interaction of intense extreme ultraviolet, soft X-ray
radiation and X-ray radiation with matter: from elemental
solids to biomolecules
(b) X-ray, extreme ultraviolet, optical, and IR emission spectroscopy of
plasmas
(c) characterization and application of neutrons and charged particles
emitted from plasmas
(d) other advanced diagnostic techniques, incl. imaging and pump-andprobe techniques
(e) characterization and applications of focused beams of short-wavelength
lasers
(f) X-ray holography with atomic resolution and related techniques
(g) chemical and plasma-chemical generators of reactive transients
(h) laser-plasma chemistry: chemical consequences of laser-induced
dielectric breakdown (LIDB) in molecular gases and their mixtures
(i) theory and computer simulations of matter interacting with intense
radiation in different spectral ranges
Warm Dense Matter - WDM
Nonideal character of plasma
is usually characterized by the
coupling parameter.
volumetric heating
In certain position, where the frequency of electrons oscillating
in plasma (plasma frequency; Langmuir frequency) is equal to
the frequency of the laser EM field, the index of refraction of the
plasma becomes zero. Thus the EM wave cannot penetrate into the plasma,
being reflected. This is called plasma mirror effect.
The plasma frequency is a function of the plasma electron density
e2 = ne e2 / 0 me
and the laser frequency is equal to the plasma frequency exactly at the critical
electron density
nc [electrons/cm3] = 1021 x -2 [m]
for  < 10 nm is nc > 1025 cm-3
 X-rays do not create a critically dense plasma so that their energy is
deposited in a volume below the irradiated solid surface
S. M. Vinko, O. Ciricosta, B.-I. Cho, K. Engelhorn, H.-K. Chung, C. Brown, T. Burian, J.
Chalupsky, R. Falcone, C. Graves, V. Hajkova, A. Higginbotham, L. Juha, J. Krzywinski, H. J.
Lee, M. Messerschmidt, C. Murphy, Y. Ping, A. Scherz, W. Schlotter, S. Toleikis, J. J. Turner, L.
Vysin, T. Wang, B. Wu, U. Zastrau, D. Zhu, R. W. Lee, P. A. Heimann, B. Nagler, J. S. Wark:
Creation and diagnosis of solid-density hot-dense matter with an X-ray free-electron
laser, Nature 482, 59 (2012). [cited: 119 times]
W. F. Schlotter et al.: The soft x-ray
instrument for materials studies at
the Linac Coherent Light Source xray free-electron laser, Rev. Sci.
Instrum. 83, 043107 (2012).
IPD – ionization potential depression
O. Ciricosta, S. M. Vinko, H.-K. Chung, B.-I. Cho,
C. R. D. Brown, T. Burian, J. Chalupský, K.
Engelhorn, R.W. Falcone, C. Graves, V. Hájková,
A. Higginbotham, L. Juha, J. Krzywinski, H. J. Lee,
M. Messerschmidt,C. D. Murphy, Y. Ping, D. S.
Rackstraw, A. Scherz, W. Schlotter, S. Toleikis, J. J.
Turner, L. Vyšín, T. Wang, B. Wu, U. Zastrau, D.
Zhu, R.W. Lee, P. Heimann, B. Nagler, J. S. Wark:
Direct measurements of the ionization potential
depression in a dense plasma, Phys. Rev. Lett.
109, 065002 (2012). [cited: 52 times]
J. C. Stewart, K. D. Pyatt: Lowering of ionization potentials in plasmas,
Astrophys. J. 144, 1203 (1966).
versus
G. Ecker, W. Kröll: Lowering of the ionization energy for a plasma in
thermodynamic equilibrium, Phys. Fluids 6, 62 (1963).
FLASH - Free-electron
LASer in Hamburg
TESLA Test Facility
(TTF 1 FEL, 1995-2002)
FLASH, 2005
experimental hall
Photon energy
Bandwidth D/
Peak power
Pulse duration
~30-300 eV
~0.5 %
>1 GW
~10-100 fs
… in-situ focus characterization
Ablative imprints in PMMA studied with use of the (a)
Navitar in the diagnostics port and (b). Nomarski DIC
microscope ex situ.
A compact diagnostics port attachable to shortwavelength beamline PG2 developed at FLASH.
N. Gerasimova et al.: Rev. Sci. Instrum. 84, 065104 (2013).
measured (partially coherent)
electrical field modulus
recovered (fully coherent)
electrical field modulus
recovered phase
recovered modulus of the
complex degree of transverse
coherence
fit of the Gaussian Schell model
recovered (partially coherent)
electrical field modulus
J. Chalupský et al.: Imprinting a focused X-ray laser beam to measure its full
spatial characteristics, Phys. Rev. Appl. 4, 014004 (2015).
PALS (Prague Asterix Laser System)
Neon-like zinc XRL driven by multi-100-ps NIR laser pulses
Simplified level scheme of neon-like zinc
Generic experimental scheme
slab target
XRL
XRL
IR laser beam
Active medium: a plasma column
created from slab target by linearly
focused NIR laser beam
Laser-plasma chemistry
with a motivation from astrobiology
M. Ferus, S. Civiš, A. Mládek, J.
Šponer, L. Juha, J. E. Šponerová:
On the road from formamide ices
to nucleobases: IR-spectroscopic
observation of a direct reaction
between cyano radicals and
formamide in a high-energy
impact event, J. Am. Chem.
Soc. 134, 20788 (2012).
For more details on laser-plasma chemistry, please, see:
L. Juha, S. Civiš: Laser-plasma chemistry: Chemical reactions
initiated by laser-produced plasmas, In: Lasers in Chemistry
(Ed. M. Lackner), Vol. 2, Wiley-VCH, Weinheim 2008, pp. 899921.
table-top capillary-discharge XUV laser
[made in Fort Collins, Colorado State University –
S. Heinbuch et al.: Opt. Express 13, 4050 (2006)]
46.9 nm
0.01 mJ
1-2 ns
10 Hz
installed in Prague
Collaboration with industry
on the development of compact high-reprate FELs
Current stage of the project: testing optical elements for
prospective high-repetition-rate soft X-ray free-electron lasers
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
Carl Zeiss SMT GmbH, Rudolf-Eber-Strasse 2, 73447 Oberkochen, Deutschland
MESA+ Institute for Nanotechnology, University of Twente, Drienerlolaan 5, 7522 NB
Enschede, The Netherlands
Institute of Physics Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw,
Poland
Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182
21 Prague 8,Czech Republic
Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
ASML Netherlands B.V., P.O. Box 324, 5500 AH Veldhoven, The Netherlands
Helmholtz-Zentrum Geesthacht, Max-Planck-Strasse 1, 21502 Geesthacht, Germany
Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany
Helmholtz Zentrum Berlin, Elektronenspeicherring BESSY-II, Institut für Nanometer Optik
und Technologie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
Teaching/training I
Charles University in Prague:
(a) Department of Chemical Physics and Optics
Teaching activities: “X-Ray Lasers and X-Ray Optics”
(NOOE130) J. Chalupský, L. Juha
Training activities: supervision of MSc and PhD thesis
(b) Department of Surface and Plasma Physics
Teaching activities: “Physics of Laser-Produced
Plasmas” (for PhD students), K. Rohlena
Training activities: supervision of M.Sc. and Ph.D.
thesis
Teaching/training II
Czech Technical University in Prague:
(c) Department of Nuclear Chemistry
Teaching activities: courses entitled
“Introduction to Photochemistry and Photobiology”
(15UFCB), L. Juha
“Theoretical Foundation of Radiation Chemistry”
(15TZRCH), L. Juha
“Radiation Chemistry and Photochemistry” (for PhD
students), L. Juha
Training activities: supervision of M.Sc. and Ph.D.
thesis
(d) Department of Physical Electronics
Training activities: supervision of M.Sc. and Ph.D.
thesis
Teaching/training III
PhD thesis defended:
J. Chalupský: Characterization of Focused Beams of
X-Ray Lasers of Various Kind (2006-2012; his
scientific achievements were awarded to a prize
Doctorandus in 2010)
M. Šmíd: X-Ray Spectroscopy of Non-Nomogeneous
Laser Plasmas (2011-2015)
M. Toufarová: Reactivity of All-Carbon
Nanostructures Exposed to Ionizing and NonIonizing Electromagnetic Radiation (2008-2015)
Future trends:
(a) hot plasmas  warm dense matter
(b) physics of LPP  laser-plasma chemistry
(c) bulk materials  interfaces
(d) large-scale facilities  compact sources in standard labs
(e) collisional plasma theory  strongly coupled systems