The He⁺ RVDF (see text for details) for different configurations of the in-ecliptic solar magnetic field angle φ_B. The top six panels show a configuration in which B is almost perpendicular with respect to v_sw, i.e. a configuration in which the ring beam distribution lies within the aperture of the PLASTIC instrument. The bottom three panels show almost radial configurations of B for which no ring beam distribution is expected to be observed within the instruments aperture.