Fig. 11
From: An in-flight plasma diagnostic package for spacecraft with electric propulsion
Demonstration of an RPA measurement in case of an ion distribution function with two populations. The figure parts (a) to (c) show the measured collector currents at the three positions −0 mm, −40 mm, and −100 mm, where the minus indicates the upper half of the chamber in Fig. 5(a). The figure parts (d) to (f) show the corresponding derivatives, respectively. The three columns of plots represent the three positions, i.e. on the beam axis (left), at the beam edge (middle), and clearly outside the beam (right)