Open AccessGas temperature measurements in a pulsed, low-pressure inductively coupled plasma in oxygen
Author(s) -
David Meehan,
Kari Niemi,
E. Wagenaars
Publication year - 2020
Publication title -
japanese journal of applied physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 129
eISSN - 1347-4065
pISSN - 0021-4922
DOI - 10.35848/1347-4065/ab7313
Subject(s) - analytical chemistry (journal) , excitation temperature , plasma , inductively coupled plasma atomic emission spectroscopy , chemistry , atomic physics , inductively coupled plasma , spectroscopy , metastability , oxygen , excited state , materials science , emission spectrum , spectral line , physics , organic chemistry , chromatography , quantum mechanics , astronomy
Optical emission spectroscopy (OES) of the magnetic dipole allowed O 2 (b 1 Σ g + ) to O 2 (X 3 Σ g − ) transition was investigated as a non-intrusive gas temperature diagnostic for E-mode and H-mode inductively coupled plasmas (ICP) in oxygen. It was compared to tunable diode laser absorption spectroscopy using Ar admixtures, and OES of the nitrogen Second Positive System with nitrogen admixtures. O 2 OES provided accurate results for the E-mode ICP, 400–600 K for powers of 100–300 W, but in H-mode the method was unsuitable probably because of excitation of O 2 (b 1 Σ g + ) by metastable atomic oxygen. Rotational temperatures were measured, using N 2 OES with N 2 admixtures, for pulsed operation of the ICP with a 30 ms pulse duration and 15% duty cycle. It took 1–3 ms before the steady-state rotational temperatures were achieved. In addition, a small variation of matching network settings affects the plasma ignition delay time by several ms.