Fig. 5
From: An in-flight plasma diagnostic package for spacecraft with electric propulsion
In-house testing of the EPDP in the chamber at the University of Kiel. (a) The sketch shows the geometrical arrangement of the ion beam and the EPDP plasma sensor head (PS). The EPDP is mounted together with additional diagnostics on the translation and rotation stage. (b) The photograph shows a view into the chamber from the position of the removed beam dump. The rotation stage is moved to the left, just as in the sketch. (The disk-like steel object below the plasma sensor is a counter weight, which is needed for mechanical stability of the rotation stage.) At the right side of the photograph, one can see the additional movable cylindrical Langmuir probe; its tip is currently at the symmetry axis of the cylindrical chamber. Behind the stage, the aperture for the Xe beam is visible. The colorful shimmer at the aperture plate and the chamber wall is caused by thin films of sputtered and deposited materials from previous experiments