Dealing with saturation of the laser‐induced fluorescence signal: An application to lead atoms
Combustion and Flame, Volume 241, July 2022, 112100
Zdeněk Bonaventura has achieved "IOP Trusted Reviewer" status.
Nima Bolouki has join our group.
David Prokop was awarded by the IGA project, Advanced time-correlated single photon counting spectroscopy.
The Technology Agency of the Czech Republic Théta project Streamers and discharges sliding on dielectric surfaces in SF6 alternatives has started on 1 January 2022 and will finish on 31 December 2024. Four partners, from both academic and private sectors, will collaborate during this project. The team members participating on the project from our university are: doc. Mgr. Tomáš Hoder, Ph.D., Mgr. Zdeněk Bonaventura, Ph.D., Jaromír Hašana, Mgr. Lucia Kuthanová, Ph.D., doc. Mgr. Pavel Slavíček, Ph.D., Mgr. Ján Tungli.
Corrigendum: Plasma Sources Science and Technology, Volume 30, Number 12, Published 23 December 2021
Original paper: Plasma Sources Science and Technology, Volume 29, Number 9, Published 14 September 2020
Plasma Sources Science and Technology, Volume 30, Number 12, Published 20 December 2021
Andrej Roštek has been chosen to receive an SVC (Society of Vacuum Coaters) Travel Support Award for SVC Technical Conference 2022 in California, USA.
The Dean of the Faculty of Science Tomáš Kašparovský honoured 36 personalities who had made a significant contribution to the development of the Faculty, and its departments and institutes, over the last few decades. Tomáš Hoder and Pavel Dvořák were among the laureates. Congratulations!
We equipped our laboratory with a new toy: laser system from Ekspla, producing picosecond pulses with wavelengths tunable in range 193 – 2300 nm.
Tomáš Hoder, Pedro Viegas and Zdeněk Bonaventura have all achieved "IOP Trusted Reviewer" status.
Several of our colleagues gave talks or presented posters this November in Prague at the 8th Plasma Science & Entrepreneurship Workshop.
Nonlinear nature of sheaths leads to nonlinear VA characteristics and generation of higher harmonic frequencies in capacitively coupled discharges. Higher harmonic frequencies are known to influence heating of electrons, especially at low pressure, and to be very sensitive to number of discharge parameters, which enables to use higher harmonics for monitoring of various deposition and etching processes. The presentation summarizes the topic of probe measurements of higher harmonic frequencies of plasma potential, nonlinear modeling of behaviour of higher harmonic frequencies in capacitive discharges and explanation of the mechanism which leads to the sensitive reaction of higher harmonics on the presence of a deposited or etched thin film.
Nanosecond-pulsed argon plasma generated in barrier discharge is widely used for many different applications and research purposes, e.g. surface treatment or plasma medicine. An important piece of information is the energy coupling between initial discharge and plasma by fast electrons. The time scales relevant for the investigation of the initiating streamer discharge tend to be of the order of hundreds of picoseconds. To obtain detailed insight into the discharge dynamics, the optical emission spectroscopy is enhanced by time-correlated single photon counting with a temporal resolution in a far sub-nanosecond range. Spatially-resolved measurements with a high temporal resolution for several selected radiative transitions of mainly 2p states give insight into the electron-argon kinetics.
Petr Bílek and his supervisor Zdeněk Bonaventura won the Vice-Rector's Award of Masaryk University for Excellence in Doctoral Studies.
Even though the 74th Annual Gaseous Electronics Conference was held as a virtual only event, it was one of the major events for our group this year. We have given 2 invited talks, 3 regular talks and presented 2 posters.
Abstract: Streamer discharges are present in many fields of science. They are basic components of atmospheric electricity and frequently utilized sources of non-equilibrium plasmas, both in fundamental research and applications. Three cases from the physics of streamer discharges are discussed in this presentation. In a free space, the quasi-stationary phase of the streamer development is a well understood phenomenon. Nevertheless the very first stages of the initiation of the streamer in pulse driven discharges lack an experimental understanding, mostly due to the diagnostical challenges connected with the high streamer velocity and its stochastic occurrence. Here, we offer an approach for such detailed diagnostics. In a similar way, the complexity and high velocity of streamer discharges developing on dielectric surfaces is the reason for unanswered questions or lack of experimental data in the field. We offer experimentally based answers to two such questions: What amplitudes can the electric field strength reach during the streamer-surface interaction? What is the initiation mechanism of long plasma filaments in surface barrier discharges? We apply the time-correlated single-photon counting-based optical emission spectroscopy to surface and coplanar barrier discharges in atmospheric air to study such phenomena. We show experimentally that the electric field amplitude reaches values of 400 kV/cm as the positive streamer propagates directly on the surface in a coplanar discharge arrangement. Furthermore, we reveal an ultra-fast development of a remotely initiated streamer cascade in the case of surface barrier discharge operated at high overvoltage. We show that this previously unknown mechanism leads to the generation of an intense cathode spot, which is a crucial condition for plasma transition to a highly-ionized state.
Abstract: The dynamical charging of a dielectric BSO target by an atmospheric pressure low-temperature plasma jet is addressed numerically and experimentally, using a two-dimensional fluid model and Mueller polarimetry measurements. The jet geometry is the same in experiments and simulations. The target is placed perpendicularly to the jet propagation and the jet is powered by rectangular pulses of applied voltage of different polarity and magnitude. The axial component of electric field inside the target is quantitatively compared between simulations and experiments, yielding excellent agreement for every studied condition, during and after the pulses. The electric field inside the target is closely related to the charge deposition on the target surface. It is shown that the spatial distribution of electric field inside the target during the pulse takes a different shape according to the jet polarity. Shortly after the pulse, charge deposition of opposite signal to the one of the applied voltage takes place. Finally, in the long time-scales in between pulses, the distributions of leftover surface charges on the target surface and leftover electric field inside the target are dependent on the polarity and magnitude of applied voltage. The discharge dynamics and the reasons behind these differences are investigated.
Tomáš Hoder was invited to give a talk at the University Paul Sabatier, Toulouse, LAPLACE. His 40 minutes long presentation was titled "Filamentary barrier discharges: sub-nanosecond dynamics, electric field and memory effects".
Tomáš Hoder spent September 2021 in the LAPLACE laboratory at the University of Paul Sabatier in Toulouse, France, as an invited professor. In cooperation with Dr.Nicolas Naudé, Dr.Antoine Belinger and Dr.Simon Dap they investigated homogeneous barrier discharges in Townsend and glow regimes at atmospheric pressure.
Adam Obrusnik was invited to give a talk at the European Conference on Plasma Diagnostics.
Two papers in PSST first-authored by Miroslav Šnírer were published less than three months apart.
Miroslav Šnírer, Vít Kudrle, Jozef Toman, Ondřej Jašek and Jana Jurmanová, Plasma Sources Sci. Technol. 30 065020, Published 17 June 2021
Tomáš Hoder and Pavel Dvořák have both been awarded as Outstanding reviewers of Plasma Sources Science and Technology journal in its 2020 Reviewer Awards.
Lukáš Kusýn started colaboration with the group of prof. Sander Nijdam in Technical university of Eindhoven (TUE) in Eindhoven, Neatherlands.
Pedro Viegas joined our group.
The Czech Science Foundation project Advanced methods for ultra-fast diagnostics of transient argon-containing plasmas has started on 1 January 2021 and will finish on 31 December 2023. The team members participating on the project are: doc. Mgr. Tomáš Hoder, Ph.D., Mgr. Zdeněk Bonaventura, Ph.D., Jaromír Hašana, Mgr. Lucia Kuthanová, Ph.D., Mgr. Martina Mrkvičková, Ph.D., Mgr. Adam Obrusník, Ph.D., Ing. David Prokop and Petr Saul.
Tomáš Hoder was invited to give a talk at the Institute of Plasma and Atomic Physics, Universität Bochum, Germany.
Tomáš Hoder gave an invited talk at the 7th Plasma Science & Entrepreneurship Workshop in Bochum, Germany.
Vít Kudrle presented a poster at the12th International Conference on Nanomaterials - Research & Application in Brno, Czech Republic.
Petr Bílek and Zdeněk Bonaventura have given their talks at the 73rd Annual Gaseous Electronics Conference.
Tomáš Hoder was invited to talk about "High-resolution diagnostics of transient non-thermal plasmas" at the Heyerovsky Institute, Prague, Czech Republic.
Petr Bílek received a honorable mention in the Milan Odehnal prize. He was awarded for study of electric field in air plasmas. Congratulations!
Miroslav Šnírer started colaboration with the group of prof. Calzada in Córdoba, Spain (UCO) during his Erasmus stay, dedicated to plasma diagnostics of graphene synthesis in TIAGO.
Two papers were published on the exact same day.
Jan Voráč, Lukáš Kusýn, and Petr Synek, Review of Scientific Instruments 90, 123102, published 3 December 2019
Plasma Sources Science and Technology, Volume 28, Number 10, Published 17 October 2019
Martin Kubečka presented a poster at the 11th International Conference on Nanomaterials - Research & Application in Brno, Czech Republic.
Zdeněk Bonaventura was invited to give a talk and Vít Kudrle presented a poster at The Joint Conference of XXXIV International Conference on Phenomena in Ionized Gases (XXXIV ICPIG) and the 10th International Conference on Reactive Plasmas (ICRP-10).
Miroslav Šnírer and Jan Faltýnek participated at the 46th European Physical Society Conference on Plasma Physics in Milan, Italy.
Adam Obrusník gave a talk at the 24th International Symposium on Plasma Chemistry in Naples, Italy.
Lukáš Kusýn presented his poster at the 13th Frontiers in Low-Temperature Plasma Diagnostics & 1st Frontiers in Low-Temperature Plasma Simulations in Bad Honnef, Germany.
Pavel Dvořák was invited to give a talk at the European Conference on Plasma Diagnostics in Lisbon, Portugal.
Chemical Science (impact factor 9.825), 10, 3643–3648, published 14 February 2019
Tomáš Hoder was invited to give a talk at the Bochum University, Germany.
Pavel Dvořák and Martina Mrkvičková gave talks at the 8th International Workshop on Plasma Spectroscopy at Worcester College, Oxford, UK.
Atomic hydrogen was measured by means of TALIF in various discharges and flames. Several aspects of the (TA)LIF method, namely partial saturation of fluorescence process, were analyzed.
We developed a theoretical model of the laser-induced fluorescence process, which predicted the shape of fluorescence non-linear dependence on energy of laser pulses. Thanks to that model, we are able to evaluate the LIF measurements also in highly saturated regime. We used this aproach for measurement of concentration of atomic lead produced in hydride atomizers for atomic absorption spectrometry, in order to understand the atomization process. We found out that the lead atoms occur mainly in the centre of the flame atomizers and the key role in atomization process is played by hydrogen atoms.
Zdeněk Bonaventura was invited to give a talk at the 6th International Congress on Energy Fluxes and Radiation Effects in Tomsk, Russia.
Vít Kudrle was invited to give a talk at the Xth INTERNATIONAL WORKSHOP on MICROWAVE DISCHARGES: Fundamentals and Applications in Zvenigorod, Russia.
August 28th - September 1st
Tomáš Hoder was invited to give a talk at the 29th Summer School and International Symposium on the Physics of Ionized Gases in Belgrade, Serbia.
OBRUSNÍK Adam, BÍLEK Petr, HODER Tomáš, ŠIMEK Milan, BONAVENTURA Zdeněk, Plasma Sources Science and Technology, Volume 27, Number 8, Published 28 August 2018
BÍLEK Petr, OBRUSNÍK Adam, HODER Tomáš, ŠIMEK Milan, BONAVENTURA Zdeněk, Plasma Sources Science and Technology, Volume 27, Number 8, Published 30 August 2018
Miroslav Šnírer presented his poster at Europhysics Conference on the Atomic and Molecular Physics of Ionized Gases in Glasgow, UK.
Miroslav Šnírer presented a poster at the 45th European Physical Society Conference on Plasma Physics in Prague, Czech Republic.
Miroslav Šnírer won "Best image in plasma science" at 45th European Physical Society Conference on Plasma Physics. Congratulations!
Tomáš Hoder was invited to give a talk at 82. Jahrestagung der DPG und DPG-Frühjahrstagung in Erlangen, Germany.
Lukáš Kusýn was awarded PhD. talent scholarship for the years 2018-2021.
Tomáš Hoder, the Vice-chair of the Local Organising Committee, and Mirko Černák, the Chair of the International Scientific Committee, have written the editorial for a special issue of Eur. Phys. J. Appl. Phys., dedicated to the HAKONE 2016 conference in Brno, organized by our department.
EUROPEAN PHYSICAL JOURNAL-APPLIED PHYSICS, Volume 79, Number 3, Published 4 August 2017
July 30th - August 4th
Tomáš Hoder was invited to give a talk at the 9th International Workshop on Microplasmas in Garmisch-Partenkirchen, Germany.
In order to precisely understand the non-equilibrium of rotational-vibrational state distribution from the investigated spectra without limiting presumptions, a state-by-state temperature-independent fitting procedure is the ideal approach. In this paper, we present an addition of novel software tool developed for this purpose into our previously published software massiveOES, freely available for the scientific community. The introduced tool offers a convenient way to construct Boltzmann plots even from partially overlapping spectra, in a user-friendly environment. We apply the novel software to the challenging case of OH spectra in surface streamer discharges generated from the triple-line of the argon/water/dielectrics interface.
Journal of Physics D: Applied Physics, Volume 50, Number 29, Published 30 June 2017
Tomáš Hoder was invited to give a talk at the 5th Workshop on Solution Plasma and Molecular Technologies in Greifswald, Germany.
The fourth (and with its 15 pages by far the longest) paper about our hypergravity experiments with gliding arc was published recently. The hypergravity conditions up to 18g were achieved at Large Diameter Centrifuge in European Space Agency research centre in Netherlands, where we got access thanks to the Spin Your Thesis! student programme.
Plasma Sources Science and Technology, Volume 26, Number 4, Published 20 March 2017
In this study, the need to batch process the massive datasets containing overlapping molecular spectra in order to obtain the spatio-temporal maps of rotational and vibrational temperatures has arisen. However, none of the publicly accessible software packages provides such functionality. We therefore developed a software, massiveOES, specifically to overcome these shortcomings. This software is now freely available to the scientific community. This paper, besides the plasma diagnostics results, also briefly discusses the data processing methods used by our software.
Plasma Sources Science and Technology, Volume 26, Number 2, Published 31 January 2017