Publication details

The statistics of spoke configurations in HiPIMS discharges

Authors

KLEIN Peter HNILICA Jaroslav ZEMÁNEK Miroslav BRADLEY James W VAŠINA Petr

Year of publication 2019
Type Article in Periodical
Magazine / Source Journal of physics D: Applied physics
MU Faculty or unit

Faculty of Science

Citation
Web Full Text
Doi http://dx.doi.org/10.1088/1361-6463/aafab3
Keywords HiPIMS; spokes; strip probe; fast camera
Description Ionisation zones, or spokes to which the discharge self-organises during the HiPIMS pulse is a recently investigated phenomenon, however adequately describing or representing these highly dynamical features is a challenge. As the spokes rotate above the target their properties can change over time, with splitting or merging frequently occurring. Here we investigate the evolution of quasi-stable spoke configurations (modes) during the HiPIMS pulse by simultaneously employing six flush mounted strip probes evenly distributed over the target and through observation by a fast camera. This arrangement was used to track the changes in the spoke configuration. The effect of the discharge current at two different pressures on the spoke configuration was statistically examined. A large amount of data was evaluated to claim that at the pressure of 0.2 Pa, there exists an equal probability for spokes to merge and to split. By contrast, spoke configurations at a pressure of 4 Pa exhibited a strong driving force towards higher spoke mode numbers, which was reflected in a significantly higher occurrence of spoke splitting over spoke merging. A simple phenomenological model describing spoke merging and splitting is presented.
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