Applicability of Heavy Ion Beam Probing for Stellarator W7-X

A feasibility study for the heavy ion beam probe on the Wendelstein 7-X (W7-X) stellarator was done to provide measurements of the radial profiles of plasma potential, density, and their fluctuations. Calculations of probing Tl⁺ beam trajectories were done for the various W7-X magnetic configurations with B_tor = 2.5 T. They show that satisfactory access is possible for K11-N11 port combination. The trajectory optimization aiming for the maximal plasma observation was done for the chosen port combination.