High-parameters experimental linear plasma device for fusion wall conditioning studies

The tungsten (W) impurity caused by sputtering of the first wall is considered as an issue influencing the plasma safe operation of EAST, ITER and other future fusion devices. The linear plasma device (LPD) serves as an effective divertor simulator for the W impurity control research. This work presents the design and construction of High-parameters Experimental Linear Plasma Device (HELPD) in detail, including its layout and operation parameters. Besides the function of plasma exposure, the target sample could be exchanged in a separate material pretreatment vessel for wall conditioning, such as lithium coating and glow discharge cleaning (GDC) without breaking vacuum conditions. And the preliminary results show that the device could produce a steady state plasma with incident ion energy of 1∼10 eV and the flux of 1022 m−2s−1 with 10 kW helicon wave. In future, HELPD would provide valuable platform for PWI evolution experiments towards future longer pulse high performance H-mode operation.