Development of HTS Current Feeder Quench Detection System for the EAST Tokamak

A high temperature superconductor (HTS) current feeder system is used as the current transmission lines for EAST Tokamak. It consists of a pair of 16 kA HTS current feeder for the Toroidal Field (TF) coils, 6 pairs of 15 kA current feeders for Central Solenoid (CS) coils and 6 pairs of 15 kA current feeders for the Poloidal Field (PF) coils. The HTS magnets are made of Bi-2223/Ag-Au alloy tapes supplied by American Superconductor Corporation. Several methods have been used for quench detection in the EAST HTS current feeder. For the investigated conditions, detecting resistance voltage shows the best performance as the main quench detection method due to the fastest response time. This paper describes the design of HTS current feeder quench detection system for EAST and emphasizes the development of detecting system in the recent EAST operating scenarios. The relevant upgrade woke for the detecting system has also been assessed in the various operating conditions especially including quench events.