Pushing the boundaries of established plasma diagnostics*

While low temperature atmospheric pressure plasma diagnostics have been extensively studied in the last decades, there remains a strong need for improved diagnostics to increase our understanding of the underlying plasma processes particularly of emerging applications. The interpretation of plasma diagnostics poses often challenges due the distinctive non-equilibrium properties of atmospheric pressure plasmas in combination with their high collisional nature. This is further enhanced by spatial gradients down to micrometer length scale, transient behavior down to nanosecond timescales and challenging operation conditions required for some applications.

 The presentation will summarize the state of the art of well-established diagnostics for atmospheric pressure plasmas including Thomson scattering, laser induced fluorescence, broad band absorption spectroscopy and mass spectrometry. We will highlight some examples that illustrate the capability to advance these diagnostics by enabling a more convenient implementation approach, a broader detection range of species and the investigation of more challenging plasma conditions.