Gas-Discharge Anemometer for the Investigation of Flow Dynamics in Rarefied Gas Media

A gas-discharge anemometer is designed for investigating the gas-flow dynamics in wind tunnels, and in experimental and space meteorology. The anemometer allows one to measure simultaneously the magnitude and direction of the gas-flow velocity vector and the gas pressure in the flow. The instrument consists of a gas-discharge chamber, an analyzer of scattered ions, a power supply unit, and a measuring unit. The anemometer weight does not exceed 0.1 kg, and the power consumption does not exceed 0.2 W. The instrument was put through preliminary tests in a wind tunnel that simulated, in particular, the conditions in the boundary layer of the Martian atmosphere and produced a directed gas (air or CO₂) flow whose velocity could be varied from 0.5 to 50 m/s at pressures from 0.3 to 1.3 kPa and temperatures from –120 to +20°C. The anemometer sensitivity is no worse than 100 mV/(m/s). The method of calculating the gas-flow velocity on the basis of the measured ion-current distributions is developed.     

Electron guns for spacecraft

Studies of three versions of electron guns (0.3 kV, 0.14 A; 20 kV, 0.1 A; 40 kV, 0.05 A) intended to operate aboard spacecraft during various space experiments are presented. The computer simulation results of electron-optical systems are given, the optimization of cathode-heating units and heat removal system are performed, circuit design of the gun power supplies for both the stationary mode and using a special modulator are discussed.