This title appears in the Scientific Report :
2019
Please use the identifier:
http://hdl.handle.net/2128/22552 in citations.
Please use the identifier: http://dx.doi.org/10.1063/1.5088931 in citations.
Polarization by light reflection at metallic surfaces observed in the shape of the Balmer- α line of low density plasmas
Polarization by light reflection at metallic surfaces observed in the shape of the Balmer- α line of low density plasmas
The degree of linear polarization of light reflected at metallic surfaces is obtained from the shape of the Balmer-α line measured in a low density plasma. The measurements of the polarization properties of metallic surfaces utilize only the high-resolution emission spectra induced by fast reflected...
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Personal Name(s): | Dickheuer, Sven |
---|---|
Marchuk, Oleksandr (Corresponding author) / Krasikov, Yuri / Mertens, Philippe / Brandt, Christian / Ertmer, Stephan / Börner, Petra / Reiter, Detlev / Göths, Beatrix / von Bovert, Kalle / Kreter, Arkadi | |
Contributing Institute: |
Plasmaphysik; IEK-4 |
Published in: | Physics of plasmas, 26 (2019) 7, S. 073513 - |
Imprint: |
[S.l.]
American Institute of Physics
2019
|
DOI: |
10.1063/1.5088931 |
Document Type: |
Journal Article |
Research Program: |
Plasma-Wall-Interaction |
Link: |
Published on 2019-07-29. Available in OpenAccess from 2020-07-29. Published on 2019-07-29. Available in OpenAccess from 2020-07-29. |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1063/1.5088931 in citations.
The degree of linear polarization of light reflected at metallic surfaces is obtained from the shape of the Balmer-α line measured in a low density plasma. The measurements of the polarization properties of metallic surfaces utilize only the high-resolution emission spectra induced by fast reflected H atoms (≈100 eV) in ArH plasmas. The measurements are performed at two different lines-of-sight to the target surfaces of Mo and Cu. Only at the observation angle close to the Brewster one, a significant drop of the measured red-shifted signal is detected for the Mo target: the red-shifted emission reduces by ≈50% depending on whether the transverse (S) or the parallel (P) polarization component of the reflected light is selected. In contrast to this, a very weak change of emission is observed for the Cu surface for the same angle. The spectra measured in front of the Mo target were modeled utilizing the energy and angular distribution of reflected atoms and excitation of the cross section of Ar-H collision combined in a Doppler-shifted emission model. A good agreement with the theoretical calculations is found for polarization components (except for the weak P polarization at 70°). Finally, the undercosine distribution of the reflected atoms with b ≈ 0.2 (b is the power of the cosine distribution) shows the best agreement with the spectra measured at both lines-of-sight |