PostGraduate School on Computational Astro- and Space Plasma Physics

11 Sept 2023, 09:00 → 15 Sept 2023, 14:00 Europe/Berlin

Ruhr University Bochum

The school is directed at early career scientists (Bachelor to Postdoc) in plasma- and astrophysics, who will have the chance to learn and practice methods commonly used in this field. The topics of the school will cover
 

• MHD and two fluid plasma descriptions (FD/FV methods)
• Particle in Cell and Vlasov simulations (explicit, implicit and relativistic solvers)
• Finite Element Exterior Calculus (PIC/Maxwell equations)
• Cosmic Ray transport and diffusion (CRPropa, synthetic turbulence)
• Applications to space and astrophysical plasmas 

 

The school is limited to 30 participants. The registration deadline is August 10, 2023.

There are no registration fees.

Financial support is not provided; we can help with finding affordable accommodation on campus 
 

Monday 11 September

09:00 → 09:15 Welcome

Speaker: Maria Elena Innocenti (Ruhr University Bochum)

09:15 → 10:45 Introductory talk: Solar physics and space weather simulations

Speaker: Stefaan Poedts (University of Leuven)

10:45 → 11:15 Coffee

11:15 → 12:15 MHD /1

The MHD model of plasmas will be reviewed. Fundamental Finite-Difference schemes and a generic and robust Finite-Volume scheme for time-dependent fluid computations will be discussed.

Speaker: Jürgen Dreher

12:15 → 14:00 Lunch

14:00 → 15:00 MHD/ 2

The MHD model of plasmas will be reviewed. Fundamental Finite-Difference schemes and a generic and robust Finite-Volume scheme for time-dependent fluid computations will be discussed.

Speaker: Jürgen Dreher

15:00 → 17:00 Fluid/ MHD: Hands on exercises

Speakers: Jürgen Dreher, Rainer Grauer

17:30 → 19:30 Icebreaker (in students' room NB 03)

Tuesday 12 September

09:00 → 10:30 Explicit Particle-In-Cell

In this lecture, we will introduce the Particle-In-Cell method, which consists into the coupling of a kinetic description of the plasma (macroparticles) with the projection on a grid of the fields, and develop the most basic method to implement it, e.g. the explicit description.

Speaker: Jérémy Dargent

10:30 → 11:00 Coffee

11:00 → 12:15 Implicit Particle-In-Cell

In this lecture, we will introduce (semi-)implicit Particle-In-Cell methods, where the equations for the temporal update of fields and particles are discretised semi-implicitly. We will discuss how the increased algorithmic burden pays off in terms of relaxed stability constraints.

Speaker: Maria Elena Innocenti

12:15 → 14:00 Lunch

14:00 → 17:00 PIC: Hands on exercises

Speakers: Jérémy Dargent, Maria Elena Innocenti

Wednesday 13 September

09:00 → 10:30 Finite elements and structure preserving Particle-In-Cell

In this lecture, we will introduce the framework of finite element exterior calculus which consists of a special type of finite elements that are adapted to the structure of Maxwell's equations and apply those to derive a structure-preserving particle-in-cell code of high accuracy order.

Speaker: Katharina Kormann (Ruhr University Bochum)

10:30 → 11:00 Coffee

11:00 → 12:15 Relativistic Particle-In-Cell

Here we will explore how fully relativistic effects can be taken into account in the Particle-In-Cell method, take a look at several applications where that can take advantage of this such as systems with energetic non-thermal tails or plasmas in extreme conditions, and consider the differences between explicit and implicit implementations.

Speaker: Kevin Schoeffler

12:15 → 14:00 Lunch

14:00 → 17:00 Particle In Cell: Hands on exercises

Speakers: Alfredo Micera, Kevin Schoeffler

18:00 → 19:00 Dinner in Q-West (on-campus restaurant)

Thursday 14 September

09:00 → 10:30 MuPhy: MultiPhysics framework

Collsionless astrophysical and space plasmas cover regions that typically display a separation of scales that exceeds any code's capabilities.The muphyII code utilizes a hierarchy of models with different inherent scales, unified in an adaptive framework that allows stand-alone use of models as well as a model-based dynamic and adaptive domain decomposition.This requires careful treatment of inner-domain model boundaries for model coupling, and robust time stepping algorithms, especially with the use of electron subcycling.

Speaker: Simon Lautenbach (University of Texas at Austin)

10:30 → 11:00 Coffee

11:00 → 12:15 Turbulence and cosmic rays

Cosmic rays are important messengers providing information about various remote astrophysical systems. Therefore, it is of high interest to understand the transport of these high energetic particles in the turbulent plasma environments they traverse. Contemporary models of cosmic ray transport processes will be discussed along with strategies to model the turbulence that is determining the latter.

Speakers: Horst Fichtner, Rainer Grauer

12:15 → 14:00 Lunch

14:00 → 15:30 Cosmic ray propagation in turbulent fields: Hands on exercises

We introduce a full-orbit test particle code that can propagate a large number of energetic particles in synthetic turbulence. Special emphasis is put on the turbulence geometry as either an isotropic or slab-2D composite model. Statistical analysis will be performed to determine the diffusion coefficients for different particle energies.

Speakers: Frederic Effenberger, Jeremiah Lübke

15:30 → 17:00 MuPhy: Hands on exercises

Speakers: Rainer Grauer, Simon Lautenbach (University of Texas at Austin)

Friday 15 September

09:00 → 10:30 Cosmic rays propagation: CRPropa

CRPropa is a modular open source cosmic-ray propagation framework. Particle transport can be treated in the single particle picture by solving the equation of motion or in an ensemble averaged approach, solving stochastic differential equations. Together with the implementation of all relevant loss processes and secondary production channels it forms a powerful tool to model cosmic rays and other messengers from GeV up to ZeV energies.

In this lecture we will present the underlying concept of the Monte Carlo code and discuss some recent applications of the code to diffusive shock acceleration (DSA) and how it helped to distinguish the transport mode in the face-on galaxy M51. During the exercise you will learn how to set up and run different simulation from cosmogenic neutrino production to particle acceleration.

Speaker: Sophie Aerdker

10:30 → 11:00 Coffee

11:00 → 12:15 CRPropa: Hands on exercises

Speakers: Julien Dörner, Sophie Aerdker

12:15 → 14:00 Good bye lunch