Duration
25h Th, 5h Pr
Number of credits
| Master in space sciences (120 ECTS) | 3 crédits |
Lecturer
Language(s) of instruction
English language
Organisation and examination
Teaching in the second semester
Schedule
Units courses prerequisite and corequisite
Prerequisite or corequisite units are presented within each program
Learning unit contents
Most of the matter in the universe exists as ionized material, described in terms of plasmas. The laws governing ionized gas differ from those describing a neutral fluid, owing to the importance of the electromagnetic interaction at play in plasmas. This course will aim at introducing those laws that specifically apply to plasmas.
This course will introduce the basic properties and laws governing matter in the state of plasma. We will discuss the Saha equilibrium governing the concentration of ionized material in a plasma. The basic characteristic quantities that describe a plasma will be introduced (Debye length, plasma frequency, ...). We will analyze the motion of charged particles in a magnetic field, accounting for the presence of other interaction fields (electric field, gravity) and we will describe the drift velocity that these combined interactions produce. The motion a charged particle in a non-uniform magnetic field will also be studied, and the gradient-curvature drift will be described. Adiabatic invariants will be introduced and used to describe the mirroring effect.
Fluid equations describing plasmas will be introduced as laws resulting from the computation of the moments of the Boltzmann equation, expressing the conservation of mass, momentum and energy. The electrodynamic laws will also be revised, and the generalized Ohm's law will be introduced. The plasma b parameter, which represents the ratio between the kinetic and magnetic pressure will be discussed as well. The important induction equation will be studied, introducing the concepts of magnetic diffusion and frozen-in flux.
We will then turn to the study of plasma waves and introduce the plasma frequency. We will introduce the basic wave equations of plasma physics and study the Alfvèn waves, including the sound waves and the fast and slow magnetosonic waves. The Appelton-Hartree equation and the various waves it describes will be introduced.
The important problem of discontinuities in plasma physics will be discussed and the Rankine-Hugoniot relations will be introduced. Several different types of discontinuities will be analyzed.
We will finally introduce the process of magnetic reconnection, which is at the heart of many dynamic plasma processes.
Learning outcomes of the learning unit
At the end of the course, the student will have learned
- what is a plasma and what are the parameters that describe it.
- what are the fundamental laws governing the motion of particles in a plasma
- what are the laws describing a plasma as a fluid
- what are the most important waves in a plasma
- what are discontinuities in a plasma and how they are described.
- what is the process of magnetic reconnection.
Prerequisite knowledge and skills
The student needs knowledge of mathematics and physics at the level of that taught at the level of bachelor in the physics section.
Planned learning activities and teaching methods
Mode of delivery (face-to-face ; distance-learning)
25 hours of lectures. 5 hours for exercices.
Recommended or required readings
The students will have access to the powerpoint slides of the course.
Assessment methods and criteria
Un examen écrit et un examen oral seront organisés.
Work placement(s)
Organizational remarks
Contacts
Benoît Hubert
B.Hubert@ulg.ac.be