TALIF

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.

A self-consistent fluid model has been successfully developed and employed to model an electron cyclotron resonance driven hydrogen plasma at low pressure. This model has enabled key insights to be made on the mutual interaction of microwave propagation, power density, plasma generation, and species transport at conditions where the critical plasma density is exceeded. The model has been verified by two experimental methods.

Absolute ground state atomic hydrogen densities were measured, by utilisation of two-photon absorption laser induced fluorescence (TALIF), in a low pressure electron cyclotron resonance plasma as a function of nitrogen admixtures - 0 to 5000 ppm. At nitrogen admixtures of 1500 ppm and higher the spectral distribution of the fluorescence changes from a single Gaussian to a double Gaussian distribution; this is due to a separate, nascent, contribution arising from the photolysis of an ammonia molecule.