LANGMUIR PROBES' SECONDARY POWER SUPPLY SYSTEM FOR THE "OBSTANOVKA" EXPERIMENT AND PLASMA-WAVE COMPLEX ABOARD THE RUSSIAN SEGMENT OF THE INTERNATIONAL SPACE STATION

The Plasma-wave complex is scientific instrumentation for plasma and wave parameters measurements in the vicinity of the International Space Station, and is implemented in the "Obstanovka" experiment aboard the Russian segment. The Langmuir probes instruments, developed at the Space Research and Technology Institute of the Bulgarian Academy of Sciences, measured the following parameters: electron temperature, electron and ion concentration, plasma and the International Space Station's surface potential. One of the results is that sharp jumps in the surface potential are detected when crossing the terminator and the Equatorial anomaly. The Langmuir probes operate outside the Russian "Zvezda" module. Families of voltage-ampere characteristics of the Langmuir probe are measured when the voltage changes in a certain range, the value of the current flowing is recorded. There are block and functional diagrams of the instrument Langmuir probes and its secondary power supply system, designed to supply the measuring probe, the analogue and digital circuit boards.