A rocket Langmuir sonde for measurements of the plasma characteristics in the lower ionosphere

Abstract

The design of a rocket Langmuir sonde is described. The electrical circuits of the EU are presented and their specific features are considered. Laboratory investigations of the EU were performed. The nonlinearity of each of six channels of amplifiers–converters does not exceed 1%. The range of the sonde-recorded signals is 30 pA–5 μA; the nonlinearity (as a function of time) of the generator-formed potential at the measuring electrode is 1% or less. Bench tests were performed that confirmed the serviceability of the sonde under the conditions of mechanical and thermal loads that occur during a rocket flight. The technical possibilities of the sonde make it possible to monitor the charged component in the lower ionosphere (100–300 km) from a meteorological rocket; in this case, the density variations of the flows of free electrons and positive ions to the measuring electrode relative to their average value may amount to 2 orders of magnitude. In comparison to its analogues, the sonde provides a higher sensitivity of measurements and a higher time resolution and distorts the electric field in the vicinity of the measuring electrode to a lower degree. The electron-energy distribution function can be reconstructed from the current–voltage characteristic up to the energies of epithermal electrons.