Probe Measurements of Plasma Parameters in Torch Plasmatron

An electric probe for a torch plasmatron has been manufactured so that to match physical parameters for a descent spacecraft at the Earth atmosphere. There is no material able to bear temperatures 5000–8000 K for long, so the probe has been made of refractory metals in a ceramic shell and it has been used as a measuring unit for a short time, with its metal part and ceramic shell being collapsed simultaneously. The experimental measurement of plasma electro-conductivity is performed with the double probe inside a torch plasmatron. The oscillograms for electric current and voltage are obtained, the volt-ampere characteristics of various plasmas (nitrogen and argon) are plotted, the plasma electro-conductivity is experimentally determined and numerically calculated.