“…The operating temperature range of the DEMO Hall sensors will vary depending on the location of the sensors. In the case of outer-vessel sensors, it will be close to the vacuum vessel temperature, which will be approximately 200 • C [23]. In the case of inner-vessel sensors, the sensor temperature will be in the range of 300 to 520 • C [23,24]; the higher operating temperature compared to ITER exceeds the range of applicability of the bismuth sensors as bismuth melts at 271.4 • C. Therefore, several metal sensitive layers that can operate at these temperatures have been researched [22,23].…”