The probe tip is made of a high-temperature material, usually a tungsten rod or wire 0.1–1 mm in diameter. The rod is threaded into a thin ceramic tube, usually alumina, to insulate it from the plasma except for a short length of exposed tip, about 2–10 mm long. These materials ...
Spherical probes have better plasma diagnostic but the diameter of the probe's tip has to be larger than the plasma Debye length which can be challenging when a nanosatellite is car-rying the mission. The design of a pair of spherical Langmuir probes for a low earth orbit CubeSat considering...
with either 6 or 13 mm radius for different plasma densities,as the probe head,and is welded to a copper plated,0.8 mm diameter welding rod that runs along a double holed ceramic tube.The other hole of the tube holds another