Školitel: David Tsiklauri, Ph.D., Prof. RNDr. Jana Šafránková, DrSc., Prof. RNDr. Zdeněk Němeček, DrSc.
Stav práce: přerušená
Abstrakt:
There are two fundamentally different levels of modelling of plasma by means of (i) magnetohydrodynamic (MHD) i.e., fluid-like description and (ii) fully kinetic, for example Particle-In-Cell (PIC) or Vlasov, i.e., when individual plasma particle dynamics is resolved. The advantages of MHD modelling are that it can successfully model large volumes such as entire solar coronal active regions (ARs) or entire magnetosphere of Earth and its interaction with the solar wind. The disadvantage of MHD modelling is that whilst it gets the basic picture right, it ignores rich physics of wave-particle interactions, plasma micro-instabilities, fast magnetic reconnection and alike. The advantages of kinetic, PIC, modelling include ability to resolve full plasma-kinetic picture, i.e., rich diversity of wave-particle interactions, plasma micro-instabilities, fast magnetic reconnection. The major disadvantage of the kinetic modelling is that is can model only small volumes of space and for short time duration.
In these projects we aim to use MHD and PIC descriptions, namely state of the art 3D MHD and PIC numerical codes developed in Great Britain, to model exciting, unsolved problems in Solar and Space Physics.
Theme 3: Major advance in this field has been discovery by David Tsiklauri of a new electron acceleration mechanism [4-6] which has won him British Royal Astronomical Society's Fowler Prize in 2009. In this project, we plan to apply this mechanism to the solar wind. In particular, we plan to add the effect of presence of He++ ion and a wide spectrum of the Aflven waves.
Theme 4: We plan to use realistic magnetic fields from solar observations and associated flows to study how realistic drivers such as magnetic field fluctuations and solar flows can provide input to realistic modelling of solar coronal heating processes and associated particle acceleration.
Literature: [1] Tsiklauri, D., Missing pieces of the solar jigsaw puzzle, Astronomy #amp; Geophysics 50, 5, 5.32-5.38, 2009. [2] Boocock, C., Kusano, K., Tsiklauri, D., The effects of oscillations and collisions of emerging bipolar regions on the triggering of solar flares, Astrophys. J., 900, 1, id.65, 9 pp., 2020. [3] Boocock, C. M. and Tsiklauri, D., A simple and accurate potential magnetic field calculator for solar physics applications using staggered grids, Astron. Astrophys., 625, A47, 2019. [4] Tsiklauri, D., Three dimensional particle-in-cell simulation of particle acceleration by circularly polarised inertial Alfven waves in a transversely inhomogeneous plasma, Phys. Plasmas 19, 082903, 2012. [5] Tsiklauri, D., Particle acceleration by circularly and elliptically polarised dispersive Alfven waves in a transversely inhomogeneous plasma in the inertial and kinetic regimes, Phys. Plasmas 18, 092903, 2011. [6] Tsiklauri D., J.-I. Sakai, S. Saito, Particle-In-Cell simulations of circularly polarised Alfven wave phase mixing: A new mechanism for electron acceleration in collisionless plasmas, Astron. Astrophys., 435, 1105-1113, 2005.