Pravidelné semináře pořádáme jednou měsíčně (říjen–červen, zpravidla první pondělí v měsíci) od 13 hod v seminární místnosti pracoviště Ondřejov.
03. 03. 2014
ASU
Proton thermal energetics in the solar wind
Abstract: The proton temperature in the solar wind decreases slower than what is expected from adiabatic prediction, protons need to be heated. The proton
thermal energetics is however more complicated because the solar wind protons are only weakly affected by Coulomb collisions and, consequently,
proton parallel and perpendicular temperatures (with respect to the ambient magnetic field) need to be treated separately. Using Helios in situ observations between 0.3 and 1 AU proton parallel and perpendicular heating rates are estimated. Helios observations indicate that protons need to be heated in the perpendicular direction whereas in the parallel direction protons need to be cooled at 0.3 AU with a cooling rate comparable to the corresponding perpendicular heating rate; between 0.3 and 1 AU the required cooling rate decreases until a transition to heating occurs: by 1 AU the protons require parallel heating, with a heating rate comparable to that required to sustain the perpendicular temperature. The estimated heating and cooling rates are compared with estimations of the turbulent energy cascade rate at 1 AU and with results of numerical simulations of proton kinetic effects in the expanding solar wind.
Dále pořádáme menší semináře jednotlivých oddělení:
Semináře slunečního oddělení
Každé úterý v 13:00 (září–červen, s výjimkou úterků po celoústavním semináři) v zasedací místnosti slunečního oddělení pracoviště Ondřejov.
25/02/2014, 13:00Czech participation on the ESA Solar Orbiter project, instrument STIXAbstract: The Spectrometer Telescope for Imaging X-rays (STIX) is one of 10 instruments on board Solar Orbiter, a confirmed M-class mission of the European Space Agency (ESA) within the Cosmic Vision program scheduled to be launched in 2017. STIX applies a Fourier-imaging technique using a set of tungsten grids (at pitches from 0.038 to 1 mm) in front of 32 pixelizedCdTedetectors to provide imaging spectroscopy of solar thermal and non-thermal hard X-ray emissions from 4 to 150 keV.
Zářivě-(magneto)hydrodynamické semináře
Zpravidla 1x za 14 dní ve čtvrtek od 11 hod (říjen–červen) v zasedací místnosti slunečního oddělení pracoviště Ondřejov.
(informace nejsou k dispozici)
Semináře oddělení GPS
Zpravidla v knihovně pracoviště Praha–Spořilov v různé dny.
04. 03. 2014, 14:00Czech Technical University, PragueParticle-in-Cell (PIC) simulations of instabilities in weakly ionized plasmasAbstract: I will talk about the research done during my stay at the University of Oslo. We simulated plasma instabilities in weakly ionized plasmas under the presence of E x B fields. Both, electrons and ions were magnetised in our simulations and we changed only the type of ion-neutral collisions. For these different ion-neutral collision types we found different electron heating rates and other instability characteristics, such as electrostatic potential fluctuations and electrostatic wave spectra. At first I will present theoretical background of our research, then our results and in the end I would like to introduce current analytical study of the simulated instabilities.(Takes place at: Sporilov library)