System integration of the ITER switching networks, fast discharge units and busbars

Abstract

In ITER, switching networks and fast discharge units consist of large resistor banks which are inserted in the toroidal field, central solenoid and poloidal field circuits by means of appropriate circuit breakers. These breakers are connected by water-cooled aluminum busbars to the AC/DC thyristor converters on one side and to the superconducting coils on the other side. Switching networks are used at every pulse for plasma initiation and ramp-up, whereas fast discharge units are used to protect the superconducting coils in case of quench, by dissipating the energy stored in the coils into the resistors. This paper deals with system integration aspects, a subject which has become more and more important as a consequence of the necessity to define the requirements for the ITER buildings. In particular, seismic analyses carried out for the finalization of the layout of the toroidal field circuit busbars in the Tokamak building, features of the Resistor building and issues associated to the routing of the cables connecting the resistors to the switches located in the Tokamak complex will be described.