This title appears in the Scientific Report :
2004
Please use the identifier:
http://dx.doi.org/10.1088/0963-0252/13/2/004 in citations.
Double sheath formed between two electronegative plasmas
Double sheath formed between two electronegative plasmas
The double sheath formed by plasmas containing thermal electrons, negative ions and positive ions is investigated. In the double sheath, the positive ion flux at the sheath edge forms a higher potential plasma and the fluxes of negatively charged particles from the low potential plasma form a counte...
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Personal Name(s): | Amemiya, H. |
---|---|
Fuchs, G. | |
Contributing Institute: |
Institut für Plasmaphysik; IPP |
Published in: | Plasma sources science and technology, 13 (2004) S. 213 - 222 |
Imprint: |
Bristol
IOP Publ.
2004
|
Physical Description: |
213 - 222 |
DOI: |
10.1088/0963-0252/13/2/004 |
Document Type: |
Journal Article |
Research Program: |
Kernfusion und Plasmaforschung |
Series Title: |
Plasma Sources Science & Technology
13 |
Subject (ZB): | |
Publikationsportal JuSER |
The double sheath formed by plasmas containing thermal electrons, negative ions and positive ions is investigated. In the double sheath, the positive ion flux at the sheath edge forms a higher potential plasma and the fluxes of negatively charged particles from the low potential plasma form a counter-stream. The densities of positive ions within both plasmas have a finite ratio. Depending on the potential difference between both plasmas three cases of double sheaths can be distinguished, which we call weak, medium and strong type. The maximum flux density to be extracted and its relation to the Langmuir limit are given. Some results for current densities, potential and the density ratio are presented. The results will be useful to design negative ion sources from which negative ion beams can be extracted. The double sheath in electronegative plasmas could be a mechanism of natural potential formation in the D-layer where discharges do sometimes occur. Some instabilities are also discussed. |