Michael Komm and tokamak research
Michael Komm is the Head of the High-Temperature Plasma Physics Department at the Institute of Plasma Physics, Czech Academy of Sciences in Prague. His research focuses on nuclear fusion - specifically, how to protect the first wall of future fusion reactors from extreme heat fluxes from hot plasma. In addition to experiments on tokamaks, he is also involved in modelling the interaction of plasma with first wall components. To do this, he uses the services of a number of supercomputers, including those of IT4Innovations (IT4I).
Do you remember when and how you first encountered a supercomputer?
The first and only supercomputer I ever visited was at IT4I in Ostrava on the occasion of its commissioning. The IT4I building and the equipment of its data room left me with a very positive impression. Touring the data room in a reduced oxygen atmosphere was a bit of an adrenaline rush :)
Which supercomputers at IT4Innovations have you used?
I have been using the IT4I supercomputers for years. So far, I have used the Anselm, Salomon, and Karolina supercomputers. When it comes to foreign supercomputers, I am currently performing my computations on Italian Marconi located in Cineca and Japanese JFRS.
Which IT4Innovations supercomputer are you currently using for your research, and how important is it for your work?
I am currently using the Karolina machine for particle-in-cell simulations of fusion plasma-first wall interactions. I strive for thorough characterisation of the effect of collisions between plasma particles on the incident heat and particle fluxes and on the thermionic electron flux that can be emitted into the plasma by tungsten components when heated to temperatures near the melting point. This scenario may occur in the future, for example, on the ITER tokamak if the heat fluxes to its tungsten plates exceed a nominal rate. It is important to investigate what would happen in such a case and what the consequences would be for the lifetime of the plates and the quality of the plasma discharge.
Can you reflect on an achievement you are particularly proud of?
Last year, in collaboration with colleagues from several European fusion laboratories, I was able to experimentally demonstrate on the German ASDEX Upgrade tokamak that heat fluxes originating from plasma edge instabilities (edge-localised modes, ELMs) can be significantly reduced by injecting argon into the plasma. This approach has long been considered unfeasible in the community due to the predictions of numerical modelling. However, in plasma physics, it is still true that experiments are one step ahead of modelling. :)
A few years ago, my Swedish colleagues and I were able to augment a predictive model of thermionic flux escaping from a hot wall (e.g. tungsten) for plasmas with magnetic fields. This required a series of computationally intensive simulations, a large part of which was performed using IT4I supercomputers. I would like to thank IT4Innovations for the long-term provision of computational resources!
Štěpán Sklenák and zeolite research
RNDr. Štěpán Sklenák, PhD, DSc. has been a senior researcher at the J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences in Prague since 2004. After obtaining his PhD in 1995, he spent almost ten years at the Technion-Israel Institute of Technology, Yale University, University of California, and Michigan State University. In 2023, he received the Doctor of Chemical Sciences (DSc.) degree from the Czech Academy of Sciences.
His current research focuses on quantum chemical calculations of zeolites to model their structure, reactivity, catalytic activity, and properties.
In 2020, he received the most prestigious Czech scientific award - the Czech Head Invention Award, together with Dr Jiří Dědeček and Dr Edyta Tábor for the creation and description of the structure and reactivity of new, unique types of transition metal cation reaction centres in zeolite matrix and their application in the oxidation of methane to methanol.Do you remember when and how you first encountered a supercomputer?
I only started using supercomputers at IT4I in Ostrava. However, in 1999, I saw the decommissioned CRAY supercomputer on display at a conference in Boulder, CO, USA. It was apparently (it's been 25 years) at this institution, along with an exhibition about Cray's founder, Mr. Seymour Cray.
Which supercomputers at IT4Innovations have you used?
Anselm, Salomon, Karolina, and LUMI.
Which IT4Innovations supercomputer are you currently using for your research, and how important is it for your work?
I am currently using Karolina and Lumi to calculate realistic zeolite models. Using a supercomputer compared to a workstation (i.e., a server) will allow for calculations of zeolites with larger unit cells and use more complex computational models and more computationally intensive computational procedures. Calculations with realistic computational models will enable the estimation of realistic values of reaction energy and rates of chemical reactions catalysed by zeolites, adsorption energy of molecules on zeolites, NM, and vibrational spectra of zeolites and adsorbed molecules on zeolites.
Can you reflect on an achievement you are particularly proud of?
The Award of the Czech Head PROJEKT institute, namely the Invention Award, together with Dr Jiří Dědeček and Dr Edyta Tábor.
It is important to emphasise that the idea of splitting molecular oxygen (i.e., O2) arose in my computational modelling work and was only subsequently confirmed by experiments.
Jiří Klimeš and molecular crystals
Jiří Klimeš works at the Faculty of Mathematics and Physics of Charles University, where he leads a small research group at the Department of Chemical Physics and Optics. They are involved in developing accurate computational methods for calculating the properties of materials and their application. Currently, they are mainly working on molecular crystals, such as some drugs or crystals of simpler molecules, such as water or carbon dioxide.
Do you remember when and how you first encountered a supercomputer?
I gained my first experience with computing on remote computers during my studies when I used MetaCentrum services. This allows users to use systems of various institutions in the Czech Republic. At that time, these systems comprised servers with dozens of processors. The first supercomputer I worked on was HECToR in the UK. It had over ten thousand processors, and in 2007, it was the seventeenth most powerful supercomputer in the world. Back then, we were studying the behaviour of water on the surface of salt and needed to do a lot of computationally intensive calculations. Access to a supercomputer made our work very efficient and allowed us to understand the basic principles governing the behaviour of water and salt.
Which supercomputers at IT4Innovations have you used?
I've been performing computations using IT4Innovations (IT4I) supercomputers nearly since their inception, with my very first application for computational resources being submitted in 2015 when the Salomon supercomputer was launched. It was the first opportunity to apply for computational resources after returning from abroad. I was happy to take advantage of it, as a large part of our research needs to perform computationally intensive calculations. Without the existence of IT4I, the situation would have been much more difficult for me upon my return. Since then, we have been using everything available at IT4I.
Which IT4Innovations supercomputer are you currently using for your research, and how important is it for your work?
Our calculations can be divided into two types, with one being very high memory-intensive and the other being less demanding but again more numerous. With both types, we are mainly trying to understand the accuracy of the simulations and describe the strength of the bonds between molecules. The memory-intensive calculations are primarily performed on Karolina, using up to dozens of its individual servers simultaneously. This allows us to use over 10 TB of computational memory, which is about 1,000 times more than in classical computers. We also extensively use Barbora, as we have optimised one of our computer programs for its processors.
Can you reflect on an achievement you are particularly proud of?
I might mention a paper my postdoc and I published last year in which we analysed one type of error in our calculations. When we calculate the bonds between molecules, we often neglect electrons that are close to the atomic nuclei, or we simplify their description. This allows us to speed up our calculations by an order of magnitude, but it causes some errors in the calculated values. In our calculations, we either had to accept these errors or use a more accurate and computationally intensive description of these electrons. In our paper, we looked at how the error arises and developed a way to reduce it substantially. Although this is a very "technical" topic, I consider it essential as it will hopefully improve the reliability of the data published in the literature.
Martin Friák and development of new materials
Martin Friák works as a group leader at the Institute of Physics of Materials of the Czech Academy of Sciences in Brno. He studied solid-state physics at Masaryk University, both as a Master's and PhD student. Immediately after completing his PhD studies, he left for abroad and worked at two institutes of the Max Planck Society in Germany for 11 years. Since 2013 he has been based again in Brno. He is a theoretical physicist dedicated to computational materials science and the theory-guided design of novel materials. He teaches at Masaryk University and Brno University of Technology. For the past few years, the team has been performing computations using not only classical (super)computers but also quantum computers.
Do you remember when and how you first encountered a supercomputer?
The first time I had the amazing opportunity to be directly in the data room of a supercomputer was several years ago, thanks to IT4Innovations - as a participant in the regular autumn Users' Conference of IT4Innovations. It was great to experience what we usually only know from Hollywood "blockbusters" (in recent years it was, for example, the unforgettable movie The Martian, featuring a somewhat exaggerated scene directly from the supercomputer data room).
Which supercomputers at IT4Innovations have you used?
It is primarily Karolina and Barbora, which help us immensely in our work. However, as we have been loyal and satisfied users of IT4Innovations for many years, we also used Anselm and Salomon when these systems were still in operation.
Which IT4Innovations supercomputer are you currently using for your research, and how important is it for your work?
Within one of the projects supported by the Grant Agency of the Czech Republic, we are studying nanoparticles for medical applications (treatment of cancer by hyperthermia), specifically using Barbara. Karolina is helping us with simulations of quantum computers running in collaboration with the Massachusetts Institute of Technology (MIT) in the USA.
Can you reflect on an achievement you are particularly proud of?
For my research, I have been awarded a total of CZK 30 million for the period 2024-2029 as part of the Academic Award called Praemium Academiae, the highest award given by the Czech Academy of Sciences. I can't wait to see the development of hybrid computational materials science (combining classical and quantum computers with artificial intelligence tools) and its application in the design of novel materials.