Volume 124, Number 2, October 2018
|Number of page(s)||7|
|Section||Physics of Gases, Plasmas and Electric Discharges|
|Published online||19 November 2018|
Measuring the plasma-wall charge by infrared spectroscopy
1 Institut für Physik, Universität Greifswald - 17489 Greifswald, Germany
2 Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel - 24098 Kiel, Germany
Received: 20 July 2018
Accepted: 18 October 2018
We show that the charge accumulated by a dielectric plasma-facing solid can be measured by infrared spectroscopy. The approach utilizes a stack of materials supporting a surface plasmon resonance in the infrared. For frequencies near the Berreman resonance of the layer facing the plasma the reflectivity dip —measured from the back of the stack, not in contact with the plasma— depends strongly on the angle of incidence making it an ideal sensor for the changes of the layer's dielectric function due to the polarizability of the trapped surplus charges. The charge-induced shifts of the dip, both as a function of the angle and the frequency of the incident infrared light, are large enough to be measurable by attenuated total reflection setups.
PACS: 52.40.Kh – Plasma sheaths / 52.70.Kz – Optical (ultraviolet, visible, infrared) measurements / 73.30.+y – Surface double layers, Schottky barriers, and work functions
© EPLA, 2018
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.