Thermal-hydraulic analysis of T-cs measurement in conductor 1A of the ITERCentral Solenoid Model Coil using the M&M code

We present a rst study of current sharing temperature (T,,) tests performed over the last few months in the Central Solenoid Model Coil (CSMC) experim ent at JAERI, Naka, Japan. The CSMC is a superconducting magnet, layer-woun d two-in-hand using 18 layers of Nb3Sn two-channel cable-in-conduit conduct ors, which very recently reached a record 13 T at 46 kA DC operation. Here we apply the multi-conductor Mithrandir (M&M) code to a selected set of sho ts with different transport currents (30, 40, and 46 kA) and we concentrate on conductor 1A on the innermost (i.e., with highest magnetic field) layer . In the test, resistive heaters located upstream of layers 1 and 2 are use d to progressively and quasi-steadily increase the supercritical helium inl et temperature in the coil. The T-cs is reached when a threshold of 0.5 mV resistive voltage is measured across the coil, after which the heaters are turned off and the coil current is dumped. Computed results are compared wi th experimental data, showing good agreement in the inlet and outlet temper atures of all four heated conductors, both as T-cs is reached (30, 40 kA) a nd during the whole hour-long transient from nominal conditions to T-cs rea ched (46 kA). (C) 2001 Elsevier Science Ltd. All rights reserved.