University of Rome “Tor Vergata”
INDUSTRIAL ENGINEERING DEPARTMENT
LEVEL II MASTER IN FUSION ENERGY – SCIENCE AND ENGINEERING
(compulsory attendance of lessons)
Coordinator: Professor Francesco Romanelli
F. Romanelli (FR), P. Buratti (PB), G. Calabrò (GC)
Physics (20 h)
· Classification of plasmas, Debye length, collisions between charged particles, collisional slowing-down, plasma resistivity.
· Fusion reactor scheme, power balance, Lawson criterion, ideal ignition temperature.
· Solution of the power balance equation. Main heating and loss terms. Scaling laws for the energy confinement time. Determination of the working point of a fusion reactor.
· Charged particle motion in weakly inhomogeneous electric and magnetic fields. Drift velocity. Confinement in toroidal equilibria.
· Rotational transform. Axisymmetric and non-axisymmetric equilibrium configurations. Tokamak and Stellarator.
· Static magnetic fields. Topology of magnetic surfaces. X-point. Divertor.
Stage. ENEA Frascati. Visit to FTU. Observe an experimental session live. Excel file on power balance and flux balance.
Introduction to macroscopic plasma instabilities (4 h)
· Introduction: macroscopic vs microscopic scales.
· Experimental observations (time scales, frequencies, onset, impact):
· Classification of free-energy sources ans stabilizing factors.
· Constraints in toroidal geometry, flute modes, MHD resonance.
· Ideal and non-ideal instabilities (incl. vertical).
· Identification of observed instabilities.
· Magnetic islands in slab geometry.
· Magnetic island in cyl and toroidal geom. (seed island, error field).
Equilibrium configurations, magnetic control and plasma scenarios (6 h)
· Magnetic flux e field; normalized flux and radius coordinates.
· Equilibrium of an axisymmetric toroidal configuration; derivation of Fundamental PDE and the Grad-Shafranov equation; plasma shape in a tokamak; limiter and divertors; standard X-point and double null configurations; advanced divertor magnetic configurations (i.e., snowflake, X-divertor, Super-X divertor).
· Circuit models (for plasma, poloidal field coils and conducting structures); transformers; plasma current induction; magnetic flux balance.
· Radial built of a fusion reactor.
Home and Lab works.
 M. Ariola, A. Pironti, Magnetic Control of Tokamak Plasmas (Monograph), Springer, 2008, ISBN 978-1-84800-323-1
 Ambrosino, G., Albanese, R., Control Systems, IEEE, Vol. 25 (5), pp. 76-92, 2005
Plasma control and diagnostics
G. Ramogida (GR), G. Calabrò (GC), D. Carnevale (DC), O. Tudisco (OT)
G. Ramogida, G. Calabrò
Equilibrium configurations, magnetic control and plasma scenarios (4 h)
· Overview on numerical non-linear equilibrium evolution codes such as MAXFEA or CREATE-NL; overview on numerical equilibrium reconstruction codes such as EFIT or FIXFREE; overview on boundary reconstruction codes as XLOC.
· Time evolution of a tokamak plasma (or tokamak scenarios); tokamak time scales.
· Eddy currents and magnetic forces.
· Considerations on the design of power supply system driven in feedback by a plasma-shape control system.
Control systems (12 h)
· Dynamic systems: linear differential equations, state space representation, solutions, stability, transfer function, discretization, identification.
· Control Theory: Bode diagrams, control scheme, stability of the closed loop, Nyquist and Routh-Hurwitz criteria, performances, standard regulators, disturbance attenuation and rejection, filtering and digital implementation.
· Brief review of plasma current, position, shape control systems:
· Plasma radial position and current control
· Vertical stabilization of elongated plasmas (including introduction of vertical displacement events (VDEs), plasma disruptions and perturbations caused by ELMs)
· Plasma shape control;
Stage. Implementation of digital control systems (PC/microcontrollers).
Plasma diagnostics (12 h)
· Magnetic diagnostics: Equilibrium coils, voltage loops, saddle coils, tangential coils, Rogowski coils, diamagnetic loop, halo current sensors, Mirnov coils.
· Kinetic Parameter diagnostics. General description of main plasma diagnostics. Principle of measurements, range of validity and data availability. Diagnostic used for plasma control will be discussed in details.
Te: Electron Cyclotron Emission, Thomson Scattering
Ne: Interferometry, Reflectometry
Ti: Charge Exchange Spectroscopy, Neutron Camera
Zeff: Bremsstrahlung, Visible, UV and X Spectroscopy.
J: Motion Stark Effect, Polarimetry
Edge: Langmuir probes, lost particle diagnostics
· Diagnostic for feedback: Density control, MHD amplitude control, current profile control
· Problematic of ITER diagnostic: Magnetic measurements in steady state case, effect of high neutron flux on diagnostic components, alpha particle diagnostics.
Stage. ENEA Laboratory.
G. Granucci (GG), F. C. Mirizzi (FCM), P. Sonato (PS)
RF Heating (6 h)
· Characteristic Frequencies in magnetized Plasma. Dispersion relation for a cold plasma. Cut-off and resonances. Wave polarization. Solution of dispersion relation. Fast and slow wave. Parallel and perpendicular propagation. Wave absorption general mechanisms. ICRH. Absorption and propagation. Polarization. Minority heating. Resonances and cut-off in tokamak. Heating, current drive and MHD control with ICRH. LH wave. Absorption and propagation. Cut-off and accessibility. Launched spectra. Power Deposition. LH Current Drive. EC wave: Absorption and propagation. O-Mode and X-Mode. Density cut-off. Second Harmonic propagation. Power deposition. EC Current Drive mechanism.
ECRH System (6 h)
· ECRH System Components. Design key points. Power Source. Gyrotron. Efficiency. Double Frequencies gyrotrons. Microwave window. Output Beam characteristic. RF Load. High Voltage Power Supply. Ancillary Systems. Control and Protection system. Transmission Line. Corrugated Waveguide. Polarization control. Directional Coupler. Quasi-optical transmission line. Transmission Line selection. Launching antenna. Front steering antenna. Remote steering antenna. Real Time steering antenna. EC as a tool for plasma control. MHD control with ECRH. ECRH utilization in ITER and DEMO
Stage. ENEA Frascati. Visit to ECRH system of FTU. Participation to gyrotron conditioning session and alignment procedure. Determination of gyrotron efficiency vs main magnetic field. (Characterisation of HVPS output: voltage calibration, modulation up to 10KHz).
F. C. Mirizzi
Transmission lines theory (4 h)
· Telegraphers’ equations
· Homogeneous transmission lines
· Transmission lines in sinusoidal regime
· Lossless transmission lines
· High frequency transmission lines
· Distortionless transmission lines
· Particular case of load
· Transmission lines of particular lengths
· Coaxial cables
LHCD System (2 h)
· High power RF sources
· Transmission Lines
· Main RF components
ICRH System (2 h)
· High power RF sources
· Transmission Lines
Auxiliary Units (2 h)
· High Voltage Power Supply (HVPS)
Star Point Control HVPS
· Pulse Step Modulation HVPS
RAMI concept (2 h)
NBI systems (12 h)
· Power Balance and Heating
· NBI principles
· NBI injector components:
· PRIMA-MITICA-SPIDER the neutral beam test facility for ITER
· Developments for DEMO
· Tools for conceptual design of NBI system
S. Atzeni (SA), M. Richetta (MR), P. Gaudio (PG), R. De Angelis (RDA)
Introduction to inertial confinement fusion (8 h)
· Pulsed reactor power balance, target gain & fuel gain
· Inertial confinement fusion & confinement time; burn efficiency
· Essential ingredients of inertial fusion: fuel compression, hot spot ignition; ignition condition
· Laser driven inertial fusion basic scheme: irradiation, implosion, ignition, burn
· Back-of-the envelope estimate of target/laser parameters
· Main issues for ICF: efficient drive, efficient compression, control of symmetry, limitation of instabilities
· Basic notions on laser-plasma interaction; Laser drive: laser absorption and ablative pressure generation; rocket effect
· Rayleigh-Taylor instability in ICF
Lasers and Inertial Confinement Fusion (12 h)
· Laser – Plasma Interaction experiments.
· Some examples.
· Direct and indirect drive scheme.
· Target requirements and design.Target and laser diagnostics.
· High-energy lasers.
· Fast and shock ignition.
· Massive targets and high gains.
· ICF experiments.
Quantum electronics and plasma laboratory (8 h)
R. De Angelis
Introduction to the ABC facility (8 h)
· Optical layout and beam characteristics
· Overview of the diagnostics system
· On going research in the inertial confinement laboratory
· Focus on basic diagnostics to be used in training session (coherent optics, Time of flight, Streak camera)
Stage. ABC- inertial confinement laboratory-ENEA Frascati.
Visit to the ABC laser hall. Participation to an experimental session. Hands on experimental data (Retrieval of experimental data from basic diagnostics and derivation of physical quantities)
M. Angelone (MA), P. Batistoni (PB), R. Villari (RV), M. Pillon (MP)
Neutron Transport (10 h)
· Introduction to neutron physics. The tokamak as neutron source. The neutron transport equation.
· Integro-differential and integral forms of the transport equation. Methods to solve the transport equation.
· Approximate solution of transport equation and application to neutron shielding.
· Effects of penetrations on neutron transport and impact on design. Introduction to nuclear analysis of tokamaks
· Introduction to neutron/gamma dosimetry and its relevance to fusion reactors.
Basic neutron physics and Breeding concept (6 h)
· Nuclear constituents, Nuclear binding energy and Fusion reactions. Energy released in fusion reactions, Deuterium –Tritium fuel cycle
· Neutron interactions with matter , Production of secondary particles
· Neutron cross sections, Macroscopic cross sections and Mean Free Path. Transmutations, Neutron induced radioactivity, Nuclear Heating and Decay Heat
· Blanket functions in fusion reactors
· Blanket materials, Tritium Breeding Ratio. Reduced activation materials. Radiation damage
· European concepts of tritium breeder blankets
Neutronics and Activation calculation (6 h)
· Neutronic calculations for fusion reactors: technological issues and impact on design
· Neutron induced activation: analyses and impact on safety issues
· Neutronics and activation analyses on ITER design
Neutron sources and Material damage (6 h)
· Particle accelerators.
· Neutron sources & generators. Use in fusion technology.
· Radiation damage of materials under neutron irradiation.
Stage. ENEA C.R. Frascati
The lessons will be complemented by one week stage at ENEA C.R. Frascati. The students will study the activation induced by 14 MeV neutrons produced by the Frascati Neutron Generator (FNG) in a real structural material proposed for ITER (e.g. Eurofer-97, AISI_ SS-316 etc.). The activity will consist of :
Plasma-wall interaction and material development
G. Maddaluno (GM), E. Visca (EV), R. Montanari (RM)
Plasma-wall interaction in tokamaks (12 h)
· Introduction to plasma edge physics.
· Flows of energy and particles on the components of the first wall.
· Functional characteristics of the first wall and divertor.
· Choice of materials.
Development of fusion reactor components (12 h)
· Manufacturing: component design and application examples, destructive and non-destructive examinations, first wall and divertor realization processes.
Stage. ENEA Frascati. Visit to Special Technologies Laboratory. Participation in the activities for the ITER divertor prototype realization: manufacture and non-destructive test.
Radiation damage and fusion reactor materials (12 h)
· Interaction between radiation and solids
· Production of Frenkel pairs, displacement cascades and local effects on the chemical composition of alloys
· Defect production and reaction at high temperature
· Structural materials
· Plasma facing materials
· Blanket materials
· Microstructural characteristics and mechanical properties will presented and discussed.
Stage. Material Lab
The students will perform some experiments of X-ray diffraction to characterize the structure of metals and alloys. The features of the most common types of ductile and brittle fracture of steels will be presented through scanning electron microscopy (SEM) observations. Finally, micro-hardness and FIMEC indentation tests will be carried out to determine the mechanical characteristics of some materials of fusion interest.
Fuel cycle, safety and health physics
S. Sandri (SS), S. Tosti (ST), G. Cambi (GC),
A. Malizia (AM), A. Santucci (AS)
Health physics (4 h)
· Introduction to Radiation Protection. Radiological sources. Radiation dosimetry. Radiation hazard to humans.
· Radiation sources related to nuclear fusion facilities. Neutron activation. Tritium hazard and protection. Measurement techniques. External and internal dose assessment.
Stage. Measurement of ionizing radiation parameters. dose assessment. Radiation shielding.
Fuel cycle (12 h)
· Interaction of hydrogen isotopes with materials both ceramics and metals of interests for fusion. Mass transfer phenomena (diffusion, absorption/desorption and permeation) of hydrogen isotopes in materials. Tritium production and permeation in breeding blankets. Tritium permeation from breeding blanket into coolant: a case study.
· Gas/liquid chemical equilibria of isotopic exchange reactions of hydrogenated compounds. Main technologies and processes of the fusion fuel cycle.
· Fusion reactors fuel cycle. ITER fuel cycle. DEMO Fuel cycle. Membrane processes and technologies in the fuel cycle: a case study.
· Pure hydrogen production and exploitation. Pd-membranes for producing pure hydrogen via dehydrogenation reactions (hydrocarbons, alcohols, biomass). Production of methane via hydrogenation of CO2 and coal.
Reference. Tritium in Fusion: Production, Uses and Environmental Impact, ed. S. Tosti and N. Ghirelli, Nova Science Publishers, 2013, ISBN 978-1-62417-270-0
Nuclear safety for fusion plants (16 h)
· Safety principles in fusion nuclear plants.
· Radiological source terms.
· Tools for accident analyses.
· Probabilistic analyses.
· Deterministic analyses.
· Occupational safety.
· Waste classification and management.
· Licensing process.
Stage. Dust in a magnetic confinement fusion device and its impact on operations (4 h)
· Plasma material interactions (PMIs). Plasma interaction with the main chamber. Plasma interaction with the divertor. The divertor. The interaction modes. Main effects of interactions. Dust safety concerns. Dust mobilization problems due to a LOVA or LOCA accidents. State of the art of dust mobilization analysis.
· Dust re-suspension experiments inside STARDUST facility. Experimental thermofluidodynamic measurements inside stardust facility. Dust tracking techniques developed. Numerical simulation inside STARDUST facility in case of LOVA. STARDUST experimental and numerical results comparison.
· Laboratory activity: I will take the students where STARDUST is placed and they will realize a couple of experiments, analyzing data with MATLAB (I will let them use the codes that we developed with LABVIEW and MATLAB and I will let play the students with the NI products on a real experiment.
· The applications of free license code for dust re-suspension in the environment in the case of accident: lesson on hot spot software, practical exercitation and development of a simulation.
Stage. ENEA Frascati (4 h)
Superconductivity and magnet engineering
P. G. Medaglia (PGM), L. Muzzi (LM), A. della Corte (AdC), G. Celentano (GC),
A. Cucchiaro (AC), G. Polli (GP)
P. G. Medaglia
Basics of superconductivity (8 h)
· Superconductivity: history and phenomenology.
· Physical properties: resistivity, persistent current, thermoelectric properties, Meissner-Ochsenfeld effect, magnetic properties and levitation.
· Critical parameters: critical temperature Tc, critical field Hc, critical current density Jc.
· A qualitative short background on London theory and BCS theory.
· Type I and Type II superconductors.
· Josephson junction.
· Some examples of superconducting materials: native and artificials, low Tc and high Tc.
· A general overview on applications.
L. Muzzi, A. della Corte, G. Celentano
Superconducting conductors for nuclear fusion (10 h)
· Magnetic confinement: role and operation of magnets in a tokamak reactor.
· Superconducting strands and conductors for nuclear fusion: materials; flux jumping and AC losses; cryogenics; cable-in-conduit conductors (CICCs); Helium thermo-hydraulics in CICCs.
· Design criteria for the winding pack of a tokamak TF coil.
· The manufacture of ITER superconducting cables.
· Characteristic issues of large size, high-current Nb3Sn CICC performances: optimization margins for Nb3Sn CICC.
· Prospects for the application of High Temperature Superconductors in fusion.
ENEA Frascati: experimental measurements of superconductors; exercise on the design of the DEMO TF coil. Visit to the ITER and JT-60SA CICC production lines at the companies TRATOS Cavi (Pieve Santo Stefano - AR) and CRIOTEC Impianti (Chivasso - TO).
A. Cucchiaro, G. Polli
Tokamak magnetic system (12 h)
· Tokamak scheme: magnetic confinement, safety factor, maximum plasma current, dimensionless plasma parameters, choice of parameters of tokamak devices.
· Toroidal Magnet system: tokamak layout, magnetic ripple, toroidal magnet in plane and out of plane loads, nuclear heating and thermal analysis, toroidal magnet structural analysis.
· Poloidal magnet system: central solenoid and poloidal field system, operating conditions, plasma scenario, plasma start-up, plasma disruption loads, mechanical loads, structural analysis, cooling system.
· Toroidal Magnet Manufacture: conductor winding, double pancake stacking, winding pack impregnation, casing components preparation, winding pack installation in casing and welding, in-case impregnation and curing, casing interface machining, helium cooling pipes, final tests.
· Quality and management requirements for manufacture: quality and control plan, special process qualification, management of non-conformity and changes, audit, metrology devoted to the manufacture, acceptance data packages, release note.
Stage. Features and capability of CAD 3D Model, simplified structural analysis of the toroidal field coil.
T. N. Todd (TNT), A. Coletti (AC), P. Agostini (PA)
Tokamak engineering (12 h)
· Tokamak engineering basics: coils, vacuum vessel, plasma facing components and the principle interactions between them.
· Nuclear tokamak requirements: tritium breeding blanket and radiation shielding, fuel cycle, special diagnostics challenges.
· Estimating forces, torques and stresses in the principle components of a tokamak: coils, vacuum vessel and plasma facing components.
· The design process: Statement of Requirements, Functional Specification, Systems Interface Management; component design iteration, caveats for Finite Element Analysis.
· Use an Excel file (provided) to compare operational and disruptive loads on major components and the erosion life of plasma facing components in a small tokamak, JET, ITER and DEMO.
Reactor Engineering – Power Supply Systems (12 h)
· A Tokamak as an Electrical Machine: overview of the main electrical loads referring to ITER.
· Power Supply for Tokamak Magnets (toroidal and poloidal coils) : AC/DC naturally commutated converter (diode/ thyristor valves; commutation process; electrical design and protection criteria; general control scheme; effects on both AC network and DC loads; converter transformers) – Example on the electrical design of an AC/DC thyristor conveter.
· Power Supply for Plasma Control Coils : AC/DC forced commutated converter (IGCT valves; electrical design and protection criteria; effects on both AC network and DC loads).
· Power Supply for RF systems: Present reference for high voltage/high frequency/ low current switching power supply (IGBT valves as switches; electrical design and protection criteria; effects on both AC network and DC loads).
· Power Supply for NBI system : AC/AC/DC converters (AC/AC inverter operation concept and introduction to the present scheme for ITER).
Heat removal components (12 h)
· Concepts of heat removal components (blanket, divertor) and their functions. Remind of heat exchange laws and practical formulas. Generation/transmission of thermal power in blanket and divertor and quantification of the associated heat loads and operational temperatures.
· Fluids for heat removal (water, helium, lead lithium eutectic, lithium): physical properties and limits associated with technological use, chemical and thermal compatibility, effects under irradiation, safety aspects, compatibility with structures, heat removal performances, technical applicability. Base components of fluid systems (valves, pipes, tanks, pumps, heat exchanger) and their sizing. Sizing of a simple circuit for blanket cooling.
· Remind of mechanical properties of Fusion structural steels in terms of tensile, creep, fatigue, and ductility performances. Evaluation of primary and secondary loads affecting blanket and divertor structures. Description of the Design Rules and their application to simplified cases structures. Neutron damage of structural materials and related design limits.
· Configurations and technical solutions of helium cooled blanket concepts: HCPB, HCLL and BoP implications.
· Configurations and technical solutions of water cooled (WCLL) and self cooled (DCLL) blankets and BoP implications.
· Configurations and technical solutions of water cooled and helium cooled divertors.
P. Buratti (PB), A. Cardinali (AC), S. Briguglio (SB)
Theory and observations of plasma instabilities (8 h)
· Introduction: recall main types of observed instabilities. General stability considerations. Classification of ideal, non-ideal and kinetic instabilities.
· Ideal MHD waves. Shear-Alfvén law. Identification of driving and damping factors.
· Flute reduction. Cylindrical reduction.
· Kink modes. Ideal stability boundaries and comparison with experimental domains. The internal kink mode. Pressure-driven instabilities and beta limits. Edge Localized Modes.
· Calculation of resistive stability. Generalized Ohm law. Tearing modes. Multiple tearing modes during current penetration. Magnetic islands dynamics (metastability, locking).
· Energetic particle driven instabilities and gap modes.
· Interaction between different instabilities.
· Disruptions. Runaways.
Waves in plasma (8 h)
· Definition of plasma (particle and waves), Ionization degree, Debye length, collisions between charged particles.
· Fluid treatment approach, Euler and Maxwell equation in plasma, Fourier analysis in an ideal plasma (stationary, homogeneous and unbounded), derivation of the dielectric tensor and general dispersion relation for cold plasma. Analysis of the dispersion relation and classification of the most important propagative modes. Interest for plasma heating and thermonuclear fusion, wave power coupling from external sources (antennas). Application to tokamak devices (Lower Hybrid Wave). Examples of other kind of applications (Plasma Thruster (Whistler), or Transmission of Radio waves in ionosphere).
· Wave equation in case of stationary, inhomogeneous and bounded plasma. Vector PDE of the second order for the electric field components in space. 1D case, reduction of PDE system to ODE, Asymptotic techniques (WKB) in the solution of the equations. Hamiltonian formulation, Dynamic of the wave propagation, Ray Tracing for Lower Hybrid Waves. Effect of temperature in the absorption of the lower hybrid wave. Plasma heating. Hint to the quasilinear effect, current drive induced by absorption of the lower hybrid wave. Conclusions and Summary.
Burning plasma (8 h)
· Simulation approach to the investigation of burning-plasma physics. Particle in Cell (PIC) codes.
· Computational resource requirements. Porting of PIC codes on parallel computers. Distribute memory and shared memory architectures.
· Interactions between alpha particles and Alfvén modes in burning plasmas. Gap modes. Energetic particle modes.
Project management and quality control
L. Lama (LL), TBC
Project management (22 h)
· Project definition and introduction to PROJECT MANAGEMENT. Project organization: transversality. Project life-cycle: Start-up, Planning, Execution, Control, Close-out. Project stakeholders. Project scope. Project plan. Work breakdown structure.
· Project schedule. Project OBS; CBS; RBS. Planning tools: GANTT, PERT, CPM. Project monitoring and control.
· Models of project organization. Project Manager role. Risk management. Relational aspects. Project status. Multi project management. Analysis of a model of project management: Microsoft Project. Guidelines for Project Managers.