Speaker
Description
The high-temperature superconducting current lead (HTSCL) plays a key role in supplying large currents to the ITER superconducting magnets. To measure the temperature of the HTSCL cooled by helium gas, PT-100 sensors are installed at both the warm end of the HTS section and the room-temperature terminal. These sensors are exposed to a high-voltage environment, depending on the type of ITER magnet. For example, if a fast discharge occurs in the Toroidal Field (TF), Central Solenoid (CS), or Poloidal Field (PF) coils, the potential level along the current lead (CL) can reach up to 20 kV. Due to the high potential difference between the ITER magnets and the ground, the design of the temperature measurement interface, including the sensors installed on the HTSCL and the data conditioning into an analog output, must be carefully considered.
This paper presents the design, fabrication, and test results of a prototype temperature measurement system specialized for HTSCL, referred to as the High-Voltage Temperature Sensor (HVTS). Based on the technical specifications suggested by the ITER Organization (IO), functional test results—such as measurement accuracy and high-potential testing—of the HVTS will be discussed. Additionally, the long-term operational test, which has been conducted on the PF current leads of the KSTAR Tokamak at the Korea Institute of Fusion Energy (KFE), will be briefly introduced.
