Due to elevated pressure, cold atmospheric pressure plasmas generate excimer species, which can emit highly energetic photons, thus transferring energy inside the discharge and to treated substrates. However, they are difficult to assess, as they are absorbed by air or window material. Here, we present a method to measure vacuum ultraviolet photons using a monochromator with an aerodynamic window. The emission spectra of a radiofrequency‐excited atmospheric plasma jet were analyzed for typical gas mixtures. The data indicate that helium excimers contribute notably to the excitation of molecular and atomic species. The emission intensities do not follow densities of ground‐state species, underlining the variety of excitation channels and the change of the electron energy distribution function under changing gas composition.

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High power magnetron sputtering (HiPIMS) discharges generate ions with high kinetic energies in comparison to conventional dc magnetron sputtering. The peculiar shape of the ion energy distribution function (IEDF) is correlated to the formation of localized ionization zones (IZ) in the racetrack of a HiPIMS discharge, so called spokes. This is explained by a local maximum of the electrical potential inside these localized IZ. By using ion energy mass spectrometry, probe experiments and plasma spectroscopy the connection between IZ and IEDFs is evaluated with high temporal resolution. The data of a floating probe next to the target is used to directly monitor the movement of the spokes in the × E B direction. Chromium is used as target material, because the plasma undergoes a sequence from stochastic spoke formation, to regular spoke pattern rotating in the × E B direction to a homogeneous plasma torus with increasing plasma power. In particular, the analysis of the transition from the regular spoke pattern to the homogeneous plasma torus at very high plasma powers shows that the high energy part of the IEDF is not affected and only the low energy part is modified. Consequently, one could consider the homogenous plasma torus at very high plasma powers as a a single ionization zone localized over the complete torus, which is formed by merging individual spokes with increasing power. Details and consequences of that model are discussed.

High Power Impulse Magnetron Sputtering (HiPIMS) is a prominent technique to deposit superior materials due to the very energetic growth flux. The origin of this energetic growth flux is believed to be an electric potential structure inside localized ionization zones, the so-called spokes, in the HiPIMS plasma, which rotate in the E × B direction along the racetrack. The measurement of this electric potential or of the electric fields surrounding this ionization zone is extremely challenging due to the very high local power density that obstructs any traditional probe diagnostics. Here, we use a marker technique on the magnetron target to analyze the lateral transport of a target material on a HiPIMS target. We show that the target material is predominantly transported in the E × B direction irrespective of the presence of spokes. However, only when spokes are present, we observe also an enhanced transport in the opposite E × B direction. This is explained by the large electric field at the trailing edges of spokes.

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