THERMOHYDRAULICS OF CICCS WITH CENTRAL COOLING PASSAGE

The cable-in-conduit conductors for ITER will have a ''central cooling hole'', a low impedance flow channel whose purpose is to decrease the pressure drop per unit length. The helium flow and the response to temperature transients of such an arrangement has unique features compared to those of the simpler CICC's without central cooling hole. The purpose of this paper is to discuss these features and to propose a model for the description of the compressible thermohydraulics of the ITER conductors. Some typical applications of the model proposed (transient cooling of a conductor length in a magnet, quench evolution) are also shown as an example.