Zaloha - nepublikovat
2.1.2022
January 1st
David Prokop was awarded by the IGA project, Advanced time-correlated single photon counting spectroscopy.
January 1st
The TAČR 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.
December 20th
Plasma Sources Science and Technology, Volume 30, Number 12, Published 20 December 2021
Full paper
December
Andrej Roštek has been chosen to receive an SVC (Society of Vacuum Coaters) Travel Support Award for SVC Technical Conference 2022 in California, USA.
November 19th
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!
November
We equipped our laboratory with a new toy: laser system from Ekspla, producing picosecond pulses with wavelengths tunable in range 193 – 2300 nm.
November
Tomáš Hoder and Pedro Viegas have both achieved "IOP Trusted Reviewer" status.
November 8th-9th
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.
November 8th
Petr Bílek with his supervisor Zdeněk Bonaventura won the Vice-Rector's Award of Masaryk University for Excellence in Doctoral Studies.
October 4th-8th
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.
September 24th
At Plasma Froids seminary of CNRS, Tomáš Hoder gave an invited talk "Ultra-fast plasma processes in gas and liquid".
September 22nd
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".
June 7th-11th
Two papers in PSST first-authored by Miroslav Šnírer were published less than three months apart.
April 15th
Tomáš Hoder and Pavel Dvořák have both been awarded as Outstanding reviewers of Plasma Sources Science and Technology journal in its 2020 Reviewer Awards.
January-June
Lukáš Kusýn started colaboration with the group of prof. Sander Nijdam in Technical university of Eindhoven (TUE) in Eindhoven, Neatherlands.
January
Pedro Viegas joined our group.
January 1st
The GAČR 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.
December 11th
Tomáš Hoder was invited to give a talk at the Institute of Plasma and Atomic Physics, Universität Bochum, Germany.
November 2nd-3rd
Tomáš Hoder gave an invited talk at the 7th Plasma Science & Entrepreneurship Workshop in Bochum, Germany.
October 5th-9th
September 16th
Tomáš Hoder was invited to talk about "High-resolution diagnostics of transient non-thermal plasmas" at the Heyerovsky Institute, Prague, Czech Republic.
September
Petr Bílek received a honorable mention in the Milan Odehnal prize. He was awarded for study of electric field in air plasmas. Congratulations!
January-March
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.
December 3rd
Two papers were published on the exact same day.
July 8th-12th
Miroslav Šnírer gave a talk at the 46th European Physical Society Conference on Plasma Physics in Milan, Italy.
June 9th-14th
Adam Obrusník gave a talk at the 24th International Symposium on Plasma Chemistry in Naples, Italy.
May 13th-16th
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.
May 6th-9th
Pavel Dvořák was invited to give a talk at the European Conference on Plasma Diagnostics in Lisbon, Portugal.
February 14th
Chemical Science (impact factor 9.825), 10, 3643–3648, published 14 February 2019
Full paper
October 16th
Tomáš Hoder was invited to give a talk at the Bochum University, Germany.
September 23rd-26th
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.
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.
July 17th-21st
Miroslav Šnírer presented his poster at Europhysics Conference on the Atomic and Molecular Physics of Ionized Gases in Glasgow, UK.
July 2nd-6th
Miroslav Šnírer presented a poster at the 45th European Physical Society Conference on Plasma Physics in Prague, Czech Republic.
June
Miroslav Šnírer won "Best image in plasma science" at 45th European Physical Society Conference on Plasma Physics. Congratulations!
March 4th-9th
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.
August 4th
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
Full paper
July 5th-9th
Tomáš Hoder was invited to give a talk at the 9th International Workshop on Microplasmas in Garmisch-Partenkirchen, Germany.
June 30th
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
Full paper
June 27th
Tomáš Hoder was invited to give a talk at the 5th Workshop on Solution Plasma and Molecular Technologies in Greifswald, Germany.
March 20th
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
Full paper
January 31st
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
Full paper
