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: juha@fzu.cz

Main research topics:(a) interaction of intense extreme ultraviolet, soft X-ray radiation and X-ray radiation with matter: from elementalsolids 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-and-

probe 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 heatingIn 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 x-ray 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).versusG. 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

Photon energy ~30-300 eV Bandwidth /~0.5 %Peak power >1 GWPulse duration 10-100 fs

TESLA Test Facility(TTF 1 FEL, 1995-2002)

FLASH, 2005

experimental hall

… 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 short-wavelength beamline PG2 developed at FLASH.

N. Gerasimova et al.: Rev. Sci. Instrum. 84, 065104 (2013).

recovered (partially coherent) electrical field modulus

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

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

Active medium: a plasma column created from slab target by

linearly focused NIR laser beam

slab target

IR laser beamXRL

XRL

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. 899-921.

installed in Pragueinstalled in Prague

[[made in Fort Collins, Colorado State University – made in Fort Collins, Colorado State University – S. HeinbuchS. Heinbuch et al. et al.:: OptOpt.. Express Express 1313, , 4050 (2006)]4050 (2006)]

table-top capillary-discharge XUV laser

46.9 nm0.01 mJ1-2 ns10 Hz

Collaboration with industryon 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) Carl Zeiss SMT GmbH, Rudolf-Eber-Strasse 2, 73447 Oberkochen, Deutschland(2) MESA+ Institute for Nanotechnology, University of Twente, Drienerlolaan 5, 7522 NB

Enschede, The Netherlands (3) Institute of Physics Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw,

Poland (4) Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182

21 Prague 8,Czech Republic(5) Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany (6) ASML Netherlands B.V., P.O. Box 324, 5500 AH Veldhoven, The Netherlands (7) Helmholtz-Zentrum Geesthacht, Max-Planck-Strasse 1, 21502 Geesthacht, Germany (8) Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany (9) 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 OpticsTeaching activities: “X-Ray Lasers and X-Ray Optics”

(NOOE130) J. Chalupský, L. JuhaTraining activities: supervision of MSc and PhD thesis

(b) Department of Surface and Plasma PhysicsTeaching activities: “Physics of Laser-Produced

Plasmas” (for PhD students), K. RohlenaTraining activities: supervision of M.Sc. and Ph.D.

thesis

Teaching/training II Czech Technical University in Prague: (c) Department of Nuclear ChemistryTeaching 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 ElectronicsTraining 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 Non-Ionizing 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