O2

This data set contains the data shown in the corresponding publication in Applied Physics Letters (https://doi.org/10.1063/5.0160303). This publication presents a benchmark of THz absorption spectroscopy against a more established method. Atomic oxygen densities were measured with THz absorption spectroscopy and compared to those obtained from picosecond (ps) two-photon absorption laser induced fluorescence (TALIF) measurements on the same capacitively coupled radio frequency oxygen discharge.

Laser absorption spectroscopy (LAS) was applied to investigate a low pressure DC-pulsed discharge in N2-H2 gas mixtures with addition of CH4 or O2. The discharge was maintained in an industrial-scale, active screen plasma nitrocarburizing (ASPNC) reactor with a steel active screen (AS). Spectroscopic lines of CH4, NH3, HCN, CO and H2O were recorded. The dataset contains the species densities for different gas mixtures.

The data set comprises full cavity ring-down spectra and absorption coefficients obtained from on/off-resonance measurements, in order to determine the spatial distribution of H2O2 in the cold atmospheric pressure plasma jet kINPen-sci. Therefore, the plasma jet was operated with 3 slm Ar and 3000 ppm water, and was equipped with a gas curtain of 5 slm O2. To determine the effective absorption length, the H2O2 absorption was measured in radial direction. These radial fits had a Gaussian-like shape.

This data set contains the data shown in the corresponding publication in Plasma Sources Science and Technology (https://doi.org/10.1088/1361-6595/acb815). This publication presents the first implementation of terahertz (THz) quantum cascade lasers (QCLs) for high-resolution absorption spectroscopy on plasmas. Absolute densities of ground state atomic oxygen were directly obtained by using the fine structure transition at approximately 4.75 THz.