Spectroscopic characterization of atmospheric pressure argon plasmas sustained with the Torche à Injection Axiale sur Guide d'Ondes

An argon microwave (2.45 GHz) plasma produced by a microwave plasma torch known as “Torche à Injection Axiale sur Guide d'Ondes” (TIAGO) in air ambience at atmospheric pressure was experimentally characterized. The conditions for appropriate TIAGO torch operation in argon and flame morphology were researched under several experimental conditions of gas flow (0.15–5.00 L · min–1) rates and microwave input powers (100–1000 W). Gas temperature and electron density values were studied by means of optical emission spectroscopy. Besides, the processes inside the discharge and their interaction with the surrounding atmosphere were described according to the recorded spectra.

► Ar discharges generated with microwave TIAGO torch were studied by OES.
► Great influence of atmosphere surrounding the flame on discharge parameters
► Electron densities ranging from 1014 cm− 3 to 1015 cm− 3 depending on argon flow rate
► Gas temperatures ranging from 2500 K to 6000 K depending on gas flow rate
► Small impact of input power on electron density and gas temperature