Angular dependence of the floating potential in a magnetized plasma

The experiments presented in this work are part of an extended investigation aiming to understand the angular dependence of energy and particle fluxes in magnetized plasmas. Here we concentrate on measurements of the floating potential Uf as a function of angle under various conditions (npl, Te, B) and for a number of ion species (H, D, He and Ar). A pronounced reduction of Uf is experimentally observed at oblique incidence. It is found that the magnitude of this reduction correlates with the Debye length while the normalized angular dependence remains similar under all conditions investigated.