78464 - Plasma Engineering M

Learning outcomes

At the end of the course the students are able to understand the main aspects of the plasma generation and its behaviour at different operating conditions. Few plasma technologies are considered: plasma treatment of surfaces (plasma etching, deposition, implantation and sputtering), electro-plasma-dynamic and magneto-plasma-dynamic interactions and their applications, the main aspects of the thermonuclear fusion with magnetic confinement, and bio-medic plasma techniques. Therefore the students are able to operate on advanced technologies used in industry and in research field.

Course contents

Elements of Plasma Physics:

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 velocity, mass velocity of a plasma, conduction and convection electric current, elastic collisions, Coulomb collisions and non-elastic collisions in ionized gases.

Radiation processes: bound-bound radiation, spontaneous emission, forced emission and absorption, line enlargement, bound-free radiations and free-free radiation.

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

Collective phenomena and characteristic magnitudes of plasma: Debye length, Coulomb shielded potential and sheath effect, plasma own frequency, electrical conductivity in an ionized gas, Hall parameter, generalized Ohm law.

Description of magnetofluidodinamic fields: MHD approximation, Electrodynamics equations and fluid dynamics equations, diffusive and convective regimes, magnetic Reynolds number and interaction parameter, conservation equations for plasmas in partial local thermodynamic equilibrium.

Magnetofluidynamics interaction:

The principle of magneto-fluid-dynamic MHD interaction: Lorentz forces acting on a flow of plasma immersed in a magnetic field perpendicular to motion and the thermodynamic forces of motion.

Fundamental laws: Navier-Stokes laws, state laws in a plasma and electrodynamics laws, non-equilibrium conductivity and conservation laws for electrons. Quasi-monodimensional approximation of Hrtmann's electro-dynamics and flow. MHD conversion of energy. MHD interactions in hypersonic flows in the re-entry into the atmosphere of spacecraft.

Electric discharges:

Characteristics of the discharge in a  gas: energy and active secies, balance and non-equilibrium, black discharge, Townsend discharge, breakdown, glow 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.

Medical plasma applications:

Main applications: sterilization, treatment of wounds and cancer cells, treatment of biopolymers. Sterilization from viruses, bacteria, molds and disinfection from dry parasites and in aqueous solutions.

Controlled thermonuclear fusion:

Physical principle of fusion and main characteristics of fusion plasmas: main fusion reactions, Coulomb barrier and reaction probability, energy balance, breakeven criterion and ignition criterion, Lawson's law, magnetic confinement of plasma, confinement surfaces and diamagnetic properties of plasma, linear configurations, z-pinch and Bennet equation, z-pinch stabilized, toroidal configurations, equilibrium magnetic field calculation, safety factor and ergodic magnetic systems, types of toroidal configurations, the tokamak, the reversal field pinch and the stellarator, instability in fusion plasmas, MHD instability in linear configurations and toroidal configurations, stabilization of toroidal configurations, plasma heating, engineering aspects of the tokamak machine.

Plasma technologies Plasma and plasma jet torches:

Fundamental features and construction aspects of the main plasma generators used in technology, plasma etching, plasma deposition, plasma implantation, errosion and corrosion in plasmas.

Readings/Bibliography

The complete series of slides projected during the lessons, are the course notes available at the teacher's website (http://www.die.ing.unibo.it/pers/borghi/carlo.htm).

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 will be held with lectures given by the teacher. Moreover, the theoretical lessons will be integrated with lessons in the laboratory where the students will be actively involved. The theoretical lessons will be held by means of slides.

Assessment methods

The exam is oral. Every Tuesday you can take the exam by appointment with the teacher via e-mail (ca.borghi@unibo.it).

Teaching tools

The slides projected during the lessons, which build the course notes, are available on the teacher's website (http://www.die.ing.unibo.it/pers/borghi/carlo.htm).

Office hours

See the website of Carlo Angelo Borghi