The course is meant to provided experimental skills applied to the investigation of plasmas (and specifically nonneutral plasmas) and charged particle beams.
Expected learning outcomes
After attending the course, the student will possess the following set of knowledge and skills: - Basics of the theory of plasmas/nonneutral plasmas - Basic notions about the interest of experimental nonneutral plasma physics - Basics of vacuum techniques - Knowledge of the theory and practice of operation of experimental plasma machines (Penning-Malmberg traps) - Formulation and design of experiments and experimental routines - Performance of experiments with research-level instrumentation - Theory and practice of data acquisition and analysis: electrostatic signals, Fourier analysis - Theory and practice of data acquisition and analysis: phosphor screen-CCD camera images, image denoising and analysis - Preparation of experimental reports, critical evaluation of results and experimental limitations.
Lesson period: Second semester
(In case of multiple editions, please check the period, as it may vary)
LECTURES: Elements of quasi-neutral plasma physics. Introduction to nonneutral plasmas. Diocotron modes, derivation of the eigenvalue equation. Ion-induced and resistive diocotron instability. Plasma manipulation methods: Feedback damping, autoresonance. Temperature and diffusion of a trapped plasma.
Harmonic signal analysis: Fourier series, continuous and discrete Fourier transform, sampling theorem, Nyquist limit and aliasing.
Description of the experimental set-up (Penning-Malmberg trap), diagnostic tools and instrumentation in the laboratory.
Elements of vacuum techniques and electronic measurements (electrostatic signal amplifiers; transimpedance).
Introduction to data analysis: Methods, protocols, creation of analysis programs and result visualization in signal and image processing.
EXPERIMENTS (the students will perform some of the experiments listed here):
Electrostatic and optical measurements of charge and density, calibration of the CCD image.
Measurement of frequency and amplitude of the first (l=1) diocotron mode for an electron column.
Measurement of the growth rate of the l=1 mode resistive instability.
Control of the l=1 mode via feedback technique.
Excitation of the l=1 mode and characterization of the autoresonance phenomenon.
Excitation of higher-order diocotron modes by means of rotating electric fields.
Measurement of the density profile as a function of time and determination of the radial diffusion coefficient.
Measurement of the parallel (axial) temperature of the electron plasma.
Prerequisites for admission
A solid knowledge of classical mechanics, electricity and magnetism is expected. Attendance to the MSc courses 'Classical electrodynamics' and 'Plasma physics and controlled fusion' can be useful, but is not deemed as necessary.
The first part of the course consists of traditional lectures concerning the fundamental notions of plasma physics, experimental techniques and data analysis methods required to carry out the experiments. The second part is based on a series of laboratory experiments, accompanied by a general introduction and a collective discussion about methods and problems both expected a priori and identified a posteriori. Part of the time is reserved for discussion and critical assessment of data analysis and results.
Notes and articles concerning the experiments (handed out during the course). Ronald C. Davidson, "Physics of Nonneutral Plasmas", Addison-Wesley, Redwood City, 1990 (excerpts).
Assessment methods and Criteria
The examination is based on the preparation of a report concerning the experiments carried out during the course and on a 45-60 minute oral discussion. The discussion deals with the physical and technical aspects of the experiments and is meant to assess the critical evaluation abilities and the skills acquired by the student during the course.