Fusion and magnets : High field strength tokamaks : The whys and wherefores
Towards the end of the 1960s Bruno Coppi attempted to carry out an experiment centring on a tokamak - the configuration of magnetic confinement which had been emerging as the most promising in previous years. The capability acquired with ALCATOR-A of generating a high current density in plasma made it possible to show that the higher the power density deposited in plasma by the Joule effect, the higher the plasma density value at which it was possible to operate. As a result, it was possible to investigate the behaviour of tokamak discharges within a considerably greater range of density values than had previously been possible. In recent years there have been some substantial innovations in high field strength toroidal magnet technology, dedicated specifically to applications relating to fusion. Two proposals seem to show greatest promise. The first, emerging at the start of the 80s, concerns a particular form of compensatory mechanical stress. If the primary stress varies with time, ordinary prestressing clearly gives rise to less than optimum compensation. In order to obviate some limitations, in the patent mentioned above, it is suggested that the required compensatory stress is actively applied using a press or system of presses. The second patent, which is more recent, is not so much concerned with compensating the stress in the conductor due to the pressure of the toroidal magnetic field, as with directly balancing this using an additional magnetic field lying anywhere in the meridian plane of the configuration.
Bibliographic Reference: Article: Il Nuovo Saggiatore, Vol. 4 (1988) No. 5, pp. 56-65
Record Number: 199010586 / Last updated on: 1994-12-01
Original language: it
Available languages: it