Quench characteristics of HTS current lead

The studies on the high temperature superconducting(HTS) current lead for superconducting magnets are actively underway with rapid advancement in HTS conductor technology recently. HTS current lead play a role to connect the external power supply with superconducting magnet and to block conduction heat invasion from room temperature. HTS current lead consists of several HTS tapes in parallel which are soldered to the copper blocks. Based on current technology, because critical current of HTS tape along the length is different, it is difficult to make HTS current lead composed of HTS tapes with the same critical current. Therefore, the magnetic quench in HTS tape with lowest critical current among HTS tapes in charging of transport current are generated firstly. Conventionally, HTS current lead uses voltage taps to detect magnetic quench but it is difficult to estimate quench of HTS current lead in fault because quench voltage level of a HTS tape is too low. Therefore, in this study, magnetic quench detection of HTS current lead using hall probe was investigated. The magnetic field distributions in octagonal shape of HTS current lead before and after magnetic quench in charging of transport current were computed using FEM. And a octonal shape of HTS current lead was fabricated and tested in order to measure the central magnetic field of HTS current lead. Based on the results, the application feasibility of the magnetic quench detection of HTS current lead using hall probe was investigated.