Fig. 4From: The aerosol impact spectrometer: a versatile platform for studying the velocity dependence of nanoparticle-surface impact phenomenaSIMION (8.1) representation of the potentials in the NET. A positive potential is used on the outer NET mirrors to trap positive particles. Two einzel lenses operating with a negative focusing potential are mounted on either side of the central ICD tube to continually re-focus particles within the trapBack to article page