Page 87 - Fundamentals of Magnetic Thermonuclear Reactor Design

Simulation of Electromagnetic Fields Chapter | 4 71

FIGURE 4.1 Simplified 3D model of the ITER complex, taking into account the ferromag-
netic inserts and steel rebars of the building. (1) The bioshield, (2) the cylinder formed by build-
ing elements and steel doors, (3) the base, (4) the bioshield lid, (5) the walls, and (6) the base of the
aseismic section. One-fourth segment is cut away to show the interior.

ment is important when it comes to analysing a magnetic field ripple, electrical
breakdown conditions, error fields caused by magnet fabrication/assembly
tolerances, and so on.
An algorithm for EM simulations in the frames of general computer tech-
nology may be reduced to the following sequence of steps (as in the case of the
ITER machine):

l Calculations of plasma-physical parameters with 2D plasma equilibrium or
MHD codes to determine TFC and PFC currents, plasma current, toroidal
magnetic flux associated with the plasma, halo current, and so on.
l 3D simulation of EM transients.
l Calculation of electro-mechanical and thermal loads due to eddy currents.
l Combined EM and stress analyses.
l Combined analysis of EM, thermal and thermo-hydraulic processes, partic-
ularly important for energy-intensive, cryo-vacuum and cryogenic systems.
At each modelling stage, results obtained at previous stages are used as in-
puts. Several iterations are often used to optimise a technical solution. Simu-
lations may involve the use of computational models of different complexity
(Figs. 4.1–4.4), and should take into account a large number of meaningful
factors to provide overall consistency of the design and performance criteria: