PSI research in the ITER divertor parameter range at the FOM PSI-lab

FOM-Rijnhuizen is building, in cooperation with its Trilateral Euregio Cluster (TEC) partners, a PSI-laboratory to study plasma surface interaction (PSI) under extreme, ITER relevant plasma conditions. The largest linear plasma generator of PSI-lab is Magnum-PSI, and is designed to deliver up to 10 MW m^-2 power over a 10 cm diameter hydrogen plasma beam with an electron density (n_e) up to 10²¹ m^-3 and electron-temperature (T_e) between 1-5 eV. Magnum-PSI is presently under construction and its predesign is presented. Its forerunner is Pilot-PSI, in which record plasma parameters of n_e=4×10²¹ m^-3 at T_e=2 eV in a ∼1 cm wide hydrogen beam confined by a magnetic field (B) ≤1.6 T were measured at 40 mm downstream the source nozzle. At 17 mm in front of a target (located at 0.56 m distance from the source nozzle), n_e>10²¹ m^-3 and T _e≤ 4 eV have been demonstrated. Initial experiments on exposing fine-grain carbon samples are presented that showed up to 20 μm s ^-1 erosion as a demonstration of the extreme plasma conditions. Spectroscopy was applied to compare chemical erosion yields for flux densities up to 5.0×10²⁴ m^-2 s^-1.