TP1
PROF. DR. GERMASCHEWSKI & PROF. DR. TOBIAS SCHÄFER
On Monday, January 14, 2013, Prof. Dr. Germaschewski (2:15 p.m.) and Prof. Dr. Tobias Schäfer (3:00 p.m.) will give talks in room NB 7/165. Prof. Germaschewski from the Department of Physics / Space Science Center at the University of New Hampshire, Durham, USA will talk about "Exploiting the power of heterogeneous computing for kinetic simulations of plasmas", Prof. Schäfer from the Department of Mathematics at CUNY, USA will talk about "Geometric minimum action method for stochastic Burger's equation". The lectures will take place in the framework of FOR 1048 "Instabilities, Turbulence and Transport in Cosmic Magnetic Fields". Interested persons are welcome to attend.
EP2
VICTOR AMARY
From February the 4th to March the 31th Master-Student Victor Amary from the Groupe de Recherches sur l'Energétique des Milieux Ionisés (GREMI) of the Université d'Orléans has successfully completed his internship at the Institute of Application Oriented Plasma Physics (EP2).
In the course of his stay he participated in working in the Project A1 of the DFG Research Unit FOR1123 around Phd-Student Daniel Schröder and Dr. Schulz-von der Gathen. He focusses his investigations on diverse further developments concerning the Micro-Plasma Jet (µ-APPJ). By the variation of the material and the widths of the electrodes, he managed to ignite the µ-APPJ with an argon feed gas flow combined with the spectroscopic characterisation of this new operation mode of the jet device.
Victor Amary is now continuing his Master Studies at the Ruhr-Universität Bochum in course of the Erasmus Programme. The team of Project A1thanks Mr. Amary for his successful participation and wishes him all the best for his future career.
TP4
PROF. YURI LITVINENKO
Prof. Dr. Yuri Litvinenko from the University of Waikato, New Zealand, has been a guest at TP4/FOR1048 since 11.2.2013 and will give a talk on "A Numerical Study of Diffusive Cosmic-Ray Transport with Adiabatic Focusing" on Thursday, 14.02.2013, starting at 11.00 in NB 7/67. Interested parties are welcome to attend!
ABSTRACT: Focused particle transport in a nonuniform large-scale magnetic field is investigated numerically in the case of isotropic pitch-angle scattering. Evolving particle density profiles and distribution moments are computed from solutions of a system of stochastic differential equivalent to the original Fokker-Planck equation for the particle distribution. Conflicting analytical predictions for the transport coefficients in the diffusion limit, independently calculated by Beeck & Wibberenz and Shalchi, are compared with the numerical results. The reasons for the discrepancies among the analytical and numerical treatments, as well as the general limitations of the diffusion model, are discussed. The telegraph equation, derived in a higher-order expansion of the particle distribution function is shown to describe the particle transport much more accurately than the diffusion model, especially ahead of a moving density pulse.
EP2
PROF. DR. IGOR DENYSENKO
Professor Igor Denysenko of the School of Physics and Technology, V. N. Karazin Kharkiv National University, Ukraine, is a guest of Experimental Physik II from 2nd March to 15th April 2013. We continue our collaboration with Prof. Denysenko in the research field of dusty plasmas. Prof. Denysenko has developed a space-averaged global model to characterize the afterglow of pulsed argon plasmas which contain the large density of hydro-carbonaceous dust particles [1]. This global model is further developed in order to study the time evolution of the dust charge and the rate coefficient for electron collection by dust particles. During Prof. Denysenko’s stay in Bochum, we have prepared an article on this study. Furthermore, an article on a new non-invasive method for measurements of ion fluxes and ion densities in pulsed capacitively-coupled RF plasmas has been submitted. We kindly acknowledge the financial support of the Humbolt Foundation.
[1] I. Denysenko, I. Stefanovic, B. Sikimic, J. Winter, N.A. Azarenkov, and N. Sadeghi, J. Phys. D: Appl. Phys. 44 (2011) 205204