Institutskolloquium des IPP 2019

Ort: Garching und Greifswald

Physics-based Deep Learning for Fluids

Institutskolloquium
In this talk I will focus on the possibilities that arise from recent advances in the area of deep learning for accelerating and improving physics simulations. I will focus on fluids, which encompass a large class of materials we encounter in our everyday lives. In addition to being ubiquitous, the underlying physical model, the Navier-Stokes equations, at the same time represent a challenging, non-linear advection-diffusion PDE that poses interesting challenges for deep learning methods. I will explain and discuss several research projects from our lab that focus on temporal predictions of physical functions, temporally coherent adversarial training, and predictions of steady-state turbulence solutions. Among other things, it turns out to be useful to make the learning process aware of the underlying physical principles. Here, especially the transport component of the Navier-Stokes equations plays a crucial role. I will also give an outlook about open challenges in the area of deep learning for physical problems. Most importantly, trained models could server as priors for a variety of inverse and control problems. [mehr]

Linking the International System of Units to Fundamental Constants

Institutskolloquium
  • Datum: 07.06.2019
  • Uhrzeit: 09:00 - 10:30
  • Vortragende(r): Prof. Dr. Joachim Ullrich
  • Joachim Ullrich studied geophysics and physics at Frankfurt University. He held positions at GSI, Darmstadt, at the Kansas State University, the University of Missouri, was chair of Experimental Physics at the University of Freiburg, before he was appointed a Director at the Max-Planck Institute for Nuclear Physics in Heidelberg. Since 2012 he is the President of the German National Metrology Institute, PTB. He has published more than 590 research papers and received several awards. Among them the Leibniz Award of the Deutsche Forschungsgemeinschaft (DPG), the David Bates Medal of the London Institute of Physics and the Philip Morris Research Award. He is a Fellow of the American Physical Society, an External Scientific Member of the Max-Planck Society, member of the German Academy of Science and Engineering, member of acatech, member of the Berlin-Brandenburg Academy of Sciences and Humanities and Vice President of the German Institute for Standardization, DIN. In 2012 he became a member of the International Committee for Weights and Measures (CIPM) of the Meter Convention and was elected Vice President of the CIPM in 2015 and is the President of the Consultative Committee for the International Units (CCU).
  • Ort: Garching und Greifswald
  • Raum: Hörsaal D2 (Übertragung nach HGW S1)
  • Gastgeber: IPP
In November 2018, the General Conference for Weights and Measures, CGPM, established by the Metre Convention in 1875, decided on the revision of the International System of Units (SI). The signatory states of the Metre Convention represent about 98 % of the world's economic power and, thus, the SI is the very foundation of global, international trade and the reliability of measurements worldwide. As suggested by Max Planck when postulating the "Planck constant" in 1900, the revised SI shall be based on fixing the numerical values of "defining constants": the velocity of light, the elementary charge, the Boltzmann, Avogadro and the Planck constants, the Cs hyperfine clock transition and the luminous efficacy. The revision is based on our present theoretical understanding of the microscopic world and is meant to ensure that the units are valid and realizable "for all times and civilizations, throughout the Universe" as envisioned by Max Planck. The talk will give an overview on the revised SI and its advantages as compared to the previous definitions, focusing in particular on future perspectives for innovative technologies. The question of whether the "defining fundamental constants" are indeed constant in time and the topic of next generation clocks will be addressed briefly. [mehr]

How to make good decisions

Institutskolloquium
This talk will introduce into the time-honored ideal of good decision making and the reality of how people make decisions. The argument will be that often mere mortals cannot do what traditional notions of good decision making demands from them. We will consider alternatives especially in terms of simple heuristics and boosts of decision making, and explore how good this way of decision making is. [mehr]
The first significant use of ICRF occurred in the Model C stellarator in 1969, now 50 years ago. In the 70s, the emphasis was on understanding and optimizing the heating method, while in the 80s, power in the MW range became available on PLT, ASDEX, JET and TFTR. The 90s saw the start of ICRF on larger machines such as JT60, Tore Supra, Alcator C-mod and ASDEX Upgrade as well as the first applications of ICRF on D-T plasmas in JET and TFTR. ICRF capabilities beyond heating were experimentally investigated on JET in the early 2000s. From 2010, with machines such as ASDEX Upgrade and JET transiting to full-metal first walls, the interaction of the ICRF with the plasma edge became again a pressing issue. The talk aims at providing an overview of 50 years of ICRF research, thereby putting the progress of the ICRF scheme in an historical perspective. It shows what has been accomplished, how problems that surfaced have been overcome and develops a view for the future. [mehr]

Alpha channelling: status and perspectives

Institutskolloquium
  • Datum: 25.10.2019
  • Uhrzeit: 10:30 - 12:30
  • Vortragende(r): Prof. F. Romanelli
  • Francesco Romanelli has been the Leader from 2006 to 2014 of the Joint European Torus the largest magnetic fusion experiment in the world and the Leader of the European Fusion Development Agreement (EFDA), in charge of the coordination of physics and technology activities in the European fusion laboratories. In 2010 he has chaired the EIROforum partnership between the eight major European multi-governmental research organizations (CERN, ESA, ESO, EMBL, ILL, ESRF, XFEL and JET). He has directed the activities in Physics of Magnetic Confinement Fusion at ENEA Frascati from 1996 to 2006. From 2003 to 2006 he has been Chairman of the Science and Technology Advisory Committee of EFDA. He is presently Professor of Physics of Nuclear Energy at the University of Rome "Tor Vergata" and Research Director at ENEA.
  • Ort: Garching und Greifswald
  • Raum: Hörsaal D2 (Übertragung nach HGW S1)
  • Gastgeber: IPP
Alpha channelling is a mechanism to deposit the energy of the fusion-generated alpha particles directly into the bulk ion population through wave-particle interaction. Its interest is associated with the possibility of increasing the margin for high-gain operation of a burning plasma. The alpha-channelling mechanism relies on the interaction between the fusion alphas and a high-frequency wave (typically an ion Bernstein wave (IBW) obtained via mode conversion of a Fast Wave injected by an external antenna) that extracts the kinetic energy associated with perpendicular motion through a resonant interaction that breaks the magnetic moment. The crucial point is that diffusion in velocity and diffusion in space are tied together. Thus, the extraction of alpha particle energy by the IBW is associated with a radial displacement of the alpha particle towards the plasma edge. The present understanding of alpha channelling will be reviewed and the perspective for burning plasma applications will be discussed. [mehr]

Auf dem Weg zu einem integrierten Energiesystem – eine systemanalytische Betrachtung unter Einbeziehung aller Energieträger und Sektoren (Talk given in English)

Institutskolloquium
  • Datum: 15.11.2019
  • Uhrzeit: 10:30 - 12:00
  • Vortragende(r): Prof. Hans-Martin Henning
  • Prof. Dr. Hans-Martin Henning is Director of the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, Germany and Professor of “Solar Energy Systems” at the Institute of Sustainable Systems Engineering in the Faculty of Engineering, University of Freiburg. He is member of acatech (German National Academy of Science and Engineering) and spokesperson of the Fraunhofer Energy Alliance. Prof. Dr. Henning obtained his PhD in physics at Oldenburg University in 1993. Since 1994, he has been working at Fraunhofer ISE in Freiburg, holding several different positions of responsibility over the years. In 2014 he was appointed Professor of Technical Energy Systems at the Karlsruhe Institute of Technology KIT and in 2017 Director of Fraunhofer ISE. The key areas of research of Prof. Dr. Hans-Martin Henning cover technical energy systems for buildings and energy system analysis. He plays a leading role in the development of computer models for the simulation and optimization of complex energy systems and their application to investigate the development of national/regional energy systems including all energy sources, energy conversion and storage technologies and energy end-use sectors.
  • Ort: Garching und Greifswald
  • Raum: Hörsaal D2 (Übertragung nach HGW S1)
  • Gastgeber: IPP
Die Warnsignale für eine notwendige drastische Reduktion der Emission klimaschädlicher Spurengase werden immer drängender. Die Transformation der weltweiten Energieversorgung spielt dabei eine Schlüsselrolle. Erneuerbare Energien werden bei diesem Umbau – neben einer höheren Effizienz bei der Wandlung und Nutzung von Energie – eine Schlüsselrolle spielen. Die wichtigsten Quellen erneuerbarer Energien sind Solarenergie und Windenergie – dies gilt global wie in Europa und Deutschland. Wie kann es gelingen eine Energieversorgung auf diesen volatilen, wetterabhängig verfügbaren Energiequellen aufzubauen? Im Vortrag wird am Beispiel der deutschen Energieversorgung versucht, diese Frage zu beantworten und zugleich wesentliche Herausforderungen zu benennen. Dabei erweist sich eine wachsende Sektorenkopplung als ein Schlüsselmerkmal. Hierunter wird eine zunehmende Nutzung von Strom in der Mobilität und für die Bereitstellung von Wärme in Gebäuden und Industrie verstanden – direkt oder indirekt in Form von mit erneuerbarem Strom hergestellter chemischer Energieträger. [mehr]

Coding for Security and Storage

Institutskolloquium
Public-key cryptography (PKC) is the foundation for establishing secure communication between multiple parties. PKC relies on a public key, known to everyone, and a private key, generated and known only to one party, the intended receiver.Traditional PKC algorithms such as the Rivest-Shamir-Adleman (RSA) cryptosystem, whose hardness is based on the factorization of larger numbers, or Elliptic Curve Cryptography (ECC), which is based on the discrete logarithm problem, are considered insecure to attacks performed by a quantum computer. Post-quantum cryptography therefore relies on algorithms based on mathematical problems that are secure for attacks by traditional and quantum computers.This can be achieved in particular by code-based cryptosystems which are the focus of this talk.First, a system based on the hardness of list decoding rank-metric codes is presented. It is based on a repair of the so-called Faure-Loidreau system and provides significantly smaller key sizes than, e.g., the McEliece system based on Goppa codes for the same security level.Second, two further code-based cryptosystems and their implications are presented: a system based on interleaved Goppa codes and a system based on twisted Gabidulin codes.Third, an overview of our further recent work in coding for distributed storage, DNA storage, and private information retrieval is given. [mehr]

New Physics with Antimatter Traps and Trap-Based Beams — The Plasma Connection

Institutskolloquium
The development of plasma-based techniques to create novel traps and beams has enabled new investigations with antimatter [1]. [mehr]
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