Control of number of nitrogen atom and enthalpy flow into reaction chamber using pulse-modulated induction thermal plasmas

Summary form only given. Control of the number of nitrogen atoms and the enthalpy flow into a reaction chamber was investigated at the downstream portion of Ar-N₂ pulse-modulated induction thermal plasmas (PMITP) at an input power of 15 kW. The PMITP has been developed to change the coil-current amplitude periodically and then it makes the thermal plasma under the transient state. It may also produce thermally and chemically non-equilibrium conditions. In the present work, spectroscopic observation was carried out to estimate time variation and time averaged value of the number of nitrogen atom flowing into reaction chamber. Surface temperature of a titanium sample installed at the downstream portion in the reaction chamber was measured with a radiation thermometer to find the effect of control of enthalpy flow. As a result, we found the pulse modulation of the coil current can enhance the number of nitrogen atom flowing into reaction chamber, nevertheless the enthalpy flow decreases compared with a conventional steady state operation