LAUSR

Abstract The ITER divertor will have to handle the boundary plasma power exhaust in the form of high heat and particle flux. The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a plasma source development device for the proposed Material Plasma Exposure eXperiment (MPEX), which is intended to create fusion reactor divertor-like plasma conditions for studying plasma material interactions. Here, ion fluxes to various targets within Proto-MPEX are found to be 5 ± 2.5 × 1023 m−2s-1 when using only a helicon plasma source. The fluxes along the flux tube are compared for both 30 cm in front of the target and a few cm in front of the target. The emission intensity fall-off distance in front of the target is studied via Balmer series from a visible camera looking at the target. This fall-off distance of ∼2–4 cm and the dissociation and ionization mean free path of D2 being over 0.5 m leads to a conclusion that Proto-MPEX is not in a high recycling regime with helicon only plasmas.