Artistic rendition of the PLASTIC instrument (golden), its FOV is projected into 3D velocity space (red), and the trajectory of a PUI (turquoise) that gyrates around the magnetic field (black arrow). Parts of the PUIs example trajectory are outside the FOV. The probability of the particle to be measured is therefore lower than one. The inset at the bottom right provides the perspective, which looks from behind PLASTIC into its FOV.