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Abstract

Spherical electrostatic probes are in wide use for the measurement of electric fields and

plasma density. This report concentrates on the measurement of fluctuations of these quan-

tities rather than background values. Potential problems with the technique include the

influence of density fluctuations on electric field measurements and vice versa, effects of

varying satellite potential, and non-linear rectification in the probe and satellite sheaths. To

study the actual importance of these and other possible effects, we simulate the response of

the probe-satellite system to various wave phenomena in the plasma by applying approxi-

mate analytical as well as numerical methods. We use a set of non-linear probe equations,

based on probe characteristics experimentally obtained in space, and therefore essentially in-

dependent of any specific probe theory. This approach is very useful since the probe theory

for magnetized plasmas is incomplete.

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