Argon plasma jet continuum emission investigation by using different spectroscopic methods

Abstract

Radiation and temperature fields of the continuum field are determined by using different spectroscopic methods based on the spectral emission of an argon plasma jet. An interferential filter of bandwidth 2.714 nm centred at a wavelength of 633 nm is used to observe only the continuum emission and to eliminate the self-absorption phenomenon. An optical multichannel analyser (OMA) of an MOS detector is used to measure argon plasma jet volumetric emissivity under atmospheric pressure and high temperatures. An emission spectroscopic method is used to measure the Stark broadening of the hydrogen line H β and to determine the electron density. The local thermodynamic equilibrium is established and its limit is stated. The local electron temperature is determined by two methods (the continuum emission relation and the LTE relations), and the total Biberman factor is measured. The results given by the OMA are compared with those given by the imagery method. At a given wavelength, the Biberman factor, which depends on the electron temperature and the electron density, may serve as an indicator to show where the LTE prevails along the argon plasma jet core length.

Comparative study of an argon plasma and an argon copper plasma produced by an ICP torch at atmospheric pressure based on spectroscopic methods

“…With ξ fb + 50%ξ fb the gap between T e and T exc is typically around 5% on the whole radial domain which is insignificant. Similar conclusions are pointed out in [46,47] in the case of an argon plasma jet: for a total Biberman factor equal to 3.7, an electron temperature around 10 000 K, and a working wavelength around the 703.02 nm Ar I line, the accordance with LTE validity is found to be within ±10%.…”

Time-resolved tomographic measurements of temperatures in a thermal plasma jet

“…According to Dgheim [28] we have taken C=1.63x10 -43 Wm 4 K 0.5 sr -1 and =2. The neutral and electron concentrations were calculated from the ideal gas and Saha equations.…”

“…where ξ is the Biberman factor, C a constant, λ the wavelength, n e the electron concentration, T the temperature and t f is the integrated filter transmittance. According to Dgheim [28] we have taken C = 1.63 × 10 −43 W m 4 K 0.5 sr −1 and ξ = 2. The neutral and electron concentrations were calculated from the ideal gas and Saha equations.…”

Biberman ‘free–bound’ continuum correction factor approximation for line-to-continuum temperature diagnostic of aluminium laser plasma

“…hydrogen) such interaction mechanisms are well described. Standard treatments however are insufficient as the atomic mass increases [44,51].…”

“…Over the last four decades, astrophysical research has ensured a steady stream of reports on the application of the lineto-continuum technique to various plasmas generated from gaseous media. These reports focused mainly upon argon [41][42][43][44][45][46][47][48][49][50][51][52][53][54]66] and Kr [55][56][57][58][59][60][61][62][63][64][65]. This large body of work has resulted in an extensive database on the temperature, density and wavelength variation of ξ fb for these and other gases.…”