78464 - Plasma Engineering M

Learning outcomes

The course deal with the fundamental aspects of plasma industrial applications. At the end of the course the student: •is familiar with the main concepts of plasma physics (Debye length, plasma frequency, …); •is acquainted with the main reactions affecting the plasma kinetics; •has a critical knowledge of the plasma models, and their range of applicability. •Is familiar with the main plasma industrial and technological applications.

Course contents

Elements of plasma physics:

Definition of Plasma. Characteristic quantities of a plasma: Debye length, natural frequency of the plasma

Motion of charged particles: motion of a charged particle in electromagnetic fields, magnetic moment of a charged particle and adiabatic invariants, magnetic mirrors.

Radiative-collisional processes: fundamental particles of a plasma, cross sections and reaction rates, mass velocities of a plasma, conduction and convection electric currents, elastic collisions, Coulomb collisions and non-elastic collisions in ionized gases.

Radiative processes: bound-bound radiation, spontaneous emission, forced emission and absorption, line widening, bound-free radiation and free-free radiation.

Statistical behavior of plasmas: Vlasov equation. Maxwellian velocity distribution, Boltzmann relations, Saha relation and Plank relation, detailed balance principle, equilibrium regimes. Maxwell-Boltzmann equation. Fokker-Plank equation. 

Collective phenomena: Coulomb's shielded potential and sheath effect, electrical conductivity in an ionized gas, Hall parameter, generalized Ohm's law.

Plasma models: MHD model, MHD approximation; drift-diffusion model; particle models (Particle in Cell)

Magnetic fluid dynamics fields:

diffusion and convective regimes, magnetic Reynolds number and interaction parameter. Applications: MHD energy conversion, MHD interactions in hypersonic flows in spacecraft reentry.

Controlled thermonuclear fusion:

Physical principle of fusion and main characteristics of fusion plasmas: main fusion reactions, Coulomb barrier and reaction probability, energy balances, break-even and ignition criteria, Lawson's criterion, magnetic plasma confinement, confinement surfaces and diamagnetic properties of the plasma, linear configurations, z-pinch and Bennet's equation, stabilized z-pinch, toroidal configurations, calculation of the equilibrium magnetic field, safety factor and ergodicity of the magnetic system, types of toroidal configurations, tokamak, reversed field pinch and stellarator, instability in fusion plasmas, MHD instability in linear and toroidal configurations, stabilization of toroidal configurations, heating of the plasma, engineering aspects of a tokamak machine.

Electric discharges:

Characteristics of the discharge in a gas: energy and active species, equilibrium and non-equilibrium, black discharge, Townsend discharge, breakdown, glow discharge and arc discharge. High frequency discharges: inductive, capacitive and microwave discharges. The barrier discharge (DBD). Electro-fluid-dynamic interaction (EHD) in barrier discharges. Applications of the EHD effect in aeronautics.

Plasma technologies:

Plasma and plasma jet torches: fundamental characteristics and construction aspects of the main plasma generators used in the technique: plasma engraving, plasma deposit, plasma system, erosion and plasma corrosion. Some technological applications.

Aerospace applications: space propulsion, rocket equation, electric propulsion, resistorjet, ion thrusters, Hall thrusters, MPD thrusters.

Readings/Bibliography

The complete series of slides projected during the lessons is available on the IOL platform.

The texts recommended for consultation and details are:

• J.D. Jackson, “Classical Electrodynamics”, John Wiley and Sons, New York, 1975
• J.L. Shohet, “The Plasma State”, Academic Press, New York, 1971
• L. Spitzer, “Physics of Fully Ionized Gases”, Interscieces, 1962
• R.J. Rosa, “Magnetohydrodynamic Energy Conversion”, McGraw Hill, 1968
• M. Mitchner and C.H. Kruger, “Partially Ionized Gases”, John Wiley and Sons, New York, 1973
• J.R. Roth, “Industrial Plasma Engineering”, Vol. 1 and 2, Institute of Physics Publisching, Philadelphia, 1995-2000
• W.M. Stacey, “Fusion Plasma Analysis”, John Wiley and Sons, New York, 1981

Teaching methods

The course takes place on the second cycle of the second year of the master degree course in "Ingegneria dell'Energia Elettrica", and consists of 6 credits corresponding to 60 hours of lectures, during which the teacher will explain in classroom the topics covered in the program. A portion of the course will be spent in lab, where the students will be actively involved. The theoretical lessons will be held by means of slides.

Assessment methods

The exam is oral and it is aimed to assess the acquisition by the student of the basic knowledge on plasma science and technology.

During the examination the student must demonstrate an understanding of the fundamentals and the capability to apply the acquired knowledge to practical cases . During the examination, the student will present a brief report on the activities he has carried out during the lab classes, and will discuss the obtained results. The student will also be invited to discuss some of the topics taught during the course. The discussion will be aimed at confirming that the student has reached an organic view of the proposed topic, that he has achieved a good grasp of the specific technical language and has acquired synthesis and analysis abilities. The degree of satisfaction of the above mentioned requirements will be used to formulate the final score.

 

Teaching tools

The slides projected during the lessons, available on IOL platform

Office hours

See the website of Andrea Cristofolini