Performance of the US quench detection systems in the QUELL experiments

The Quench of Long Length (QUELL) experiments have been completed. The US contribution was to develop and implement both conventional and novel techniques in quench detection. The results of the quench detection experiments demonstrate that all US systems functioned as expected. The most important criteria for the comparison of the various quench detection systems were the time constant of the response and noise rejection by the system. The novel US internal (inside the CICC) sensors included; (1) a cowound voltage sensor, and (2) a fiberoptic temperature sensor. The internal sensors combined fast response with high noise rejection capacity, and proved to offer potentially high reliability for ITER. The conventional sensors, namely the absolute pressure transducer and Venturi flowmeters, confirmed inherent thermo-hydraulic time response limitations in measurements of pressure and flow that excludes them as quench detectors for ITER and other large scale CICC applications.