Shunt and Rogowski coil measurements on ASDEX Upgrade in support of DEMO detachment control

Highlights: • Aim to develop designs for performing thermo-current measurements in DEMO. • Experiments with shunts and Rogowski coils were performed in AS-DEX Upgrade. • Rogowski coil measurements require stray field compensation of poloidal and toroidal field coil currents. • Shunt measurements with a signal level of 0.75 mV can provide a useful feedback control signal. Detachment control in DEMO is a fundamental requirement to prevent damage to the plasma facing components. Thermo-currents flowing through the plasma facing components of the divertor cassette are driven by the thermoelectric voltage generated by the plasma temperature difference between the inner and outer target plates. Shunt and Rogowski coil measurements to measure thermo-currents for detachment control on ITER are planned. Thermo-current measurements on ASDEX Upgrade have been carried out in support of establishing designs considered suitable to measure thermo-currents in DEMO.