Emission spectroscopy of cw CO2 laser-sustained argon plasma: Effects of gas-flow speed

Abstract

Articles you may be interested inInvestigation into the effect of Ar ratio in He-Ar mixture side assisting gas on plasma properties during CO2 laser welding based on 3D reconstructionThe effects of elevated gas-flow speed were studied for the cw CO 2 laser-sustained argon plasma in a chamber of I-atm pressure using the argon emission spectrum. Electron temperature distribution was obtained from the 41S.8-nm An line-to-continuum intensity ratio. This temperature distribution was further utilized to calculate the fraction of laser power absorbed by the plasma, and the amount of radiation loss from the plasma. The experiments were performed for laser powers 01'2.5 and 5 kW with anf 17 lens focusing scheme, and gasflow speeds of 2-10 m/s. The results show that as high as 86% of incident laser energy can be absorbed by the plasma. Accounting for the plasma radiation loss, 41 %-62 % of the laser energy can still be retained as the gas thermal energy, which is a significant increase over the previously reported results for lower flow speed and smaller focusingfnumber. 5756

Wave Drag Reduction of Blunt Bodies Using Laser Sustained Energy Deposition In Argon Atmosphere

“…15 Furthermore, at the moment of the spectrum snapshot the thermodynamic equilibrium is not valid for a maintained plasma in quiescent gas, according to the thermal equilibrium between the absorbed laser power and the losses of convection, conduction and radiation. Temperatures in the range between 15,000 to 20,000 K have been published for CO 2 laser sustained plasmas in slow streamed argon 8,10,13 at P L = 0.7 . .…”

“…Laser heated argon plasmas have been spectroscopically investigated by Szymanski et al 10 and Chen et al 13 by observing the ArII-ArI-line intensity ratio and the ArI-continuum intensity ratio, respectively. The temperature is calculated by an atomic and an ionic line according to eq.…”