First divertor discharges on the KTM tokamak: Operational features and initial results

This paper presents the first experimental results from divertor-configuration discharges on the KTM tokamak. Stable ohmic plasmas with a lower single-null divertor configuration were successfully produced at a plasma current of 500 kA and a plasma elongation of k = 1.6. The experiments were performed without wall boronization, providing reference data for future studies of wall conditioning and plasma-facing materials. The experimental results demonstrate that the plasma evolution follows the predicted discharge scenario and that divertor operation can be achieved using only the PF1 and PF4 coils before commissioning of the dedicated HFC stabilization system. The reconstructed magnetic configuration, visible imaging, spectroscopy, and infrared diagnostics confirm the formation of a stable divertor configuration and localization of the strike points. The achieved plasma parameters approach the baseline operating regime of KTM and provide a basis for subsequent experiments involving higher plasma currents, additional ICRF heating, and dedicated plasma–wall interaction studies.