Performance and Control of 50 kW Arc Heater for Chemical Lasers

Abstract

Electric arc is a safe alternative to combustion for dissociation of SF 6 required for optimizing the experiments related to development of hydrogen fluoride/deuterium fluoride (HF/DF) laser. The plasma arc discharge in an arc heater/generator is essentially employed for inducing thermal dissociation of SF 6 for production of fluorine atoms. Another accrued advantage of using arc heater is that there is a possibility of varying the composition of the lasing mixture independently of the pressure and temperature of its constituents. However, in order to use arc heater for lasers applications, it is not only necessary to have an efficient arc heater, but interfacing it with the Data acquisition system and the laser tunnel is equally important. The paper reports the basic design and performance of 50 kW arc plasma tunnel relevant for hydrogen fluoride/deuterium fluoride (HF/DF) laser applications. Complete instrumentation required for testing and its integration with the simulated laser tunnel has been implemented. The arc behavior has been studied on the developed 50 kW arc heater with Nitrogen using a dedicated data acquisition system employing fibre optics link to cater for electromagnetic noise and hostile environment. The 50 kW arc generator should serve as a versatile tool for optimizing lasers parameters such as gas flow rate, pressure, temperature and Mach number for a kilowatt HF/DF Laser.