Duration
25h Th, 5h Pr
Number of credits
| Master in space sciences, research focus | 4 crédits | |||
| Master in space sciences, professional focus | 4 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 consider several applications of plasma physics: the basic mechanisms producing the magnetic field of celestial objects, the process of electric charge loading of the surface of satellites, and the basic principles of magnetic plasma confinment for nuclear fusion devices.
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, hybrid learning)
25 hours of lectures. 5 hours for exercices.
Course materials and recommended or required readings
The students will have access to the powerpoint slides of the course.
Any session :
- In-person
written exam ( open-ended questions ) AND oral exam
- Remote
written exam ( open-ended questions )
- If evaluation in "hybrid"
preferred remote
Additional information:
An oral and a writen examination will be organized. The theoretical evaluation will rely on a list of questions distributed beforehand.
ADAPTATION FOR YEAR 2020-2021
Due to the still apocalyptic sanitary conditions that we are experiencing, it will not be possible to organize a face-to-face oral examination. As a list of questions was distributed at the start of the term, the evaluation will remain based on this list of questions, so that the work already done is not wasted. On the agreed date of the exam, you will receive a list of 4 questions, and you will be asked to send the teacher the answer you have prepared for each of them. You will therefore need to scan your responses and send them by e-mail or other means of file exchange (eg belnet file sender, recommended by the university). The answers you scan should be handwritten (to avoid simple copy and paste), and your name should appear clearly on each page. A few sub-questions will also be added which you will have to answer in the same format: handwritten, scanned and sent work. You will only have 2 hours to submit your work. Therefore, it is advisable to scan all of your answers ahead of time. If you have no scanner, photos taken with a camera or your phone will do. Please check beforehand that your electronic version is easily readable and can be easily sent electronically. The exam will therefore be a kind of homework, but based on the list of questions provided to you. The function of the sub-questions will be to make sure that you have some knowledge of the subject.
If you have no way of producing and sending an electronic copy of your responses, contact the professor and a solution will be found.
Since the exercise sessions must be organized under unfavorable conditions, without face-to-face sessions, they will not be subject to evaluation.
Work placement(s)
Organisational remarks and main changes to the course
Contacts
Benoît Hubert
B.Hubert@ulg.ac.be