The machine design is characterized by a complete structural integration of its major components (toroidal field system, poloidal field system, central post, C-
The adopted design of the machine magnets is aimed at having a stress distribution as close as possible to an isotropic distribution in the most critical areas.
ANSALDO has carried out extensive mechanical design and structural analyses for all the main components of the machine core, the so-
In particular, the machine Central Post, the Central Solenoid, the Shape and Equilibrium coils, the Plasma Chamber and supported First Wall, the surrounding mechanical structures, the Vacuum Cryostat and supported polyethylene-
A new configuration for the cooling channels in the toroidal magnet that minimizes the distance between the region (adjacent to the central solenoid) where the maximum temperature is produced and the region reached by the coolant has been designed. For the most extreme operation parameters of the toroidal coils (13 T), the cooling time of 5 hours is reduced by a factor two, for the reduced scenarios (6-
The Plasma Chamber is a key component that has to sustain the electromagnetic and thermal loads due to plasma off–normal events, assuring the required degree of high vacuum. Moreover, it plays a role in an effective stabilization of MHD modes near the plasma boundary, given its closeness to the plasma. According to the present design, the Plasma Chamber is made of Inconel 625 for its excellent mechanical properties. In fact, Inconel (often referred to in English as "Inco"), which is a family of austenitic nickel-
The computational investigation of the toroidal distribution of the EM loads due to halo currents and a scaling to Ignitor from the values observed in JET disruptions have confirmed the value of about 10 MN for the net horizontal force produced during an off-
A High Performance Plasma Parameter Control (H3PC) is aimed at avoiding/mitigating disruptions by simultaneously regulating a number of plasma parameters (e.g. a relevant safety factor, the internal inductance, the plasma density relative to the density limit, the status of MHD activities) that can play the role of disruption precursors.
The ICRH antenna design is being carried out by Politecnico di Torino in collaboration with the Oak Ridge National Laboratories. A full size prototype of
High voltage tests, at different vacuum and pressure conditions, have been carried out to verify the capability of the system to withstand the high voltages (~ 12 kV) and electric fields (~ 5 kV/cm) associated with the maximum RF power in the presence of a strong mismatch with the plasma load.
A further important aspect of the Ignitor design is the adoption of the MgB2 (Magnesium Diboride) superconducting material for the largest poloidal coils (P14, diameter of about 5 m). These coils will be cryocooled at the operating temperature of 10-
1) F. Bombarda et al, Braz. J. Phys. 34, 1786 (2004)
2) B. Coppi et al, Overview Paper OV/P-