The ratio, R(w_sw) (Eq. (5)), of the pickup ion flux as a function of w_sw between magnetic configurations φ_⊥ and φ_∥ for He⁺, C⁺, N⁺, O⁺, and Ne⁺ (panels from left to right). The data was collected between March 2007 and December 2013 during periods in which the solar wind velocity was below 450 km s^-1. As illustrated in Fig. 5, the magnetic configurations φ_⊥ and φ_∥ correspond to configurations in which the pickup ion torus lies inside and outside the instrument’s aperture respectively. The ratio f(w)_⊥/f(w)_∥ is therefore an indicator of the relative flux increase induced by the pickup ion torus distribution or, in more general terms, an indicator for the anisotropy of the pickup ion VDF.