Abstract
In the present work, a high power (30kW), atmospheric pressure inductive thermal plasma has been diagnosed both theoretically and experimentally in pulse amplitude modulation approach with Ar, Ar-CO2, Ar-N2, and Ar-O2 as working gases (100lpm argon and 2.5lpm molecular gas). Simulation has been carried out using a two-dimensional local thermodynamic equilibrium (LTE) code for the same torch and operating conditions as that of experiment. Calculating the so-called response times from both simulated and experimental temporal radiation intensity of ArI at 751nm, a rigorous and comprehensive comparative discussion has been made for a shimmer current level (SCL), the ratio of lower to higher level of current pulse, varying from 40%—100%. The measured temperature is also compared with the calculated apparent temperature. In spite of some discrepancies (at lower SCL) with the magnitude of response times of experimental and simulated plasma at the instant of on-pulsing transition, similar trend of those have been observed. These results will help to clear the understanding of transient performance of the concerned gases and equilibrium phenomena.
