TY - JOUR

T1 - Spatially resolved LAAS/OES diagnostics of a free-burning Ar arc

T2 - Measurements of excited atom densities

AU - Kalanov, D.

AU - Kozakov, R.

AU - Siasko, A.

AU - Bösel, A.

AU - Golubovskii, Yu

AU - Gortschakow, S.

PY - 2019/2/13

Y1 - 2019/2/13

N2 - Spatially resolved optical diagnostics are applied to a free-burning DC arc in argon at atmospheric pressure. Densities of metastable and resonance 1s-atoms are measured by laser atomic absorption spectroscopy (LAAS). The novel LAAS design allowed for an extended range of wavelength scan covering the complete Stark broadened line profile (∼0.5 nm). High spatial resolution of 0.2 mm allowed measurements of atom densities and line profiles in the regions of high-temperature gradients. Besides absorbing 1s-states, the radiating 2p-states were measured using optical emission spectroscopy (OES). Results of the LAAS and OES measurements are compared with the nonequilibrium collisional-radiative model. Measurement of metastable states in the non-radiating regions near the cathode reveals the existence of a collar effect. The interpretation of the effect with a focus on transport of resonance radiation is given, quantitative agreement between simulations and experiment is reached.

AB - Spatially resolved optical diagnostics are applied to a free-burning DC arc in argon at atmospheric pressure. Densities of metastable and resonance 1s-atoms are measured by laser atomic absorption spectroscopy (LAAS). The novel LAAS design allowed for an extended range of wavelength scan covering the complete Stark broadened line profile (∼0.5 nm). High spatial resolution of 0.2 mm allowed measurements of atom densities and line profiles in the regions of high-temperature gradients. Besides absorbing 1s-states, the radiating 2p-states were measured using optical emission spectroscopy (OES). Results of the LAAS and OES measurements are compared with the nonequilibrium collisional-radiative model. Measurement of metastable states in the non-radiating regions near the cathode reveals the existence of a collar effect. The interpretation of the effect with a focus on transport of resonance radiation is given, quantitative agreement between simulations and experiment is reached.

KW - collisional-radiative model

KW - free-burning arc

KW - laser atomic absorption spectroscopy

KW - optical emission spectroscopy

KW - radiation trapping

UR - http://www.scopus.com/inward/record.url?scp=85059866951&partnerID=8YFLogxK

U2 - 10.1088/1361-6463/aaf5c1

DO - 10.1088/1361-6463/aaf5c1

M3 - Article

AN - SCOPUS:85059866951

VL - 52

JO - Journal Physics D: Applied Physics

JF - Journal Physics D: Applied Physics

SN - 0022-3727

IS - 7

M1 - 075204

ER -