Experimental simulation of the Super-X divertor for detached plasma using TPD-Sheet IV

Highlights: • Examined the backflow characteristics of neutral particles in a detached plasma. • TPD-Sheet IV with a Super-X-divertor-like target was used. • The effect caused by the divergent magnetic field to a generation of the detached plasma is small. • A backflow-suppressing "plasma plugging" effect was confirmed. • It is suggested that there is an optimal value of magnetic-field divergence for preventing backflow of neutral particles. - Abstract: We confirm the neutral-particle backflow characteristics of detached plasma with a Super-X divertor-like target using a linear divertor simulator TPD-Sheet IV. The effect of a divergent magnetic field upon the generation of the detached plasma is found to be weak. Under a divergent magnetic field, the heat load on the target plate with a Super-X divertor-like target is suggested to be reduced by 3–5 times compared with a case in which a conventional diverter (CD) is used. In addition, it is suggested that there is an optimal magnetic-field divergence that prevents backflow of neutral particles.