A plasma reactor optimized for inverted fireball experiments

In this paper, we report on an experimental setup that is optimized for studying different aspects of inverted fireballs, ranging from fundamental research to potential technological applications. The vacuum system, containing the inverted fireball plasma, is described in great detail along with the available diagnostic tools for in situ plasma monitoring. These diagnostic tools include a radially movable Langmuir probe system, a mass spectrometer, optical emission spectroscopy, adjustable heaters, mass flow controllers, and power supplies. The experimental setup is fully computerized and is able to cover several decades of pressure and utilize reactive and non-reactive gases as well as gas mixtures with a large variety of flow conditions. That is achieved by individually controlling the vacuum pump force and the flow of each individual species of the gas mixture. Measurements that demonstrate the long-term stability of the discharge are presented herein.