Plasma temperature rise toward the plasma-facing surface

TitlePlasma temperature rise toward the plasma-facing surface
Publication TypeJournal Article
Year of Publication2015
AuthorsD. Nishijima, R.P Doerner, R.P Seraydarian, G. De Temmerman, H.J van der Meiden
JournalJournal of Nuclear Materials
Volume463
IssueAug
Pagination440 - 444
Abstract

Detailed measurements of axial electron temperature, Te, profiles in the presheath region were carried out using a Langmuir probe and the line intensity ratio technique for both He I (728.1 nm/706.5 nm) and Be II (467.3 nm/313.1 nm). The results show that Te increases toward the material surface, which contradicts the standard picture that Te is constant along the magnetic field in the sheath-limited regime. While no target bias voltage, Vb, dependence is seen, the Te rise becomes more prominent with decreasing neutral pressure. Similarly, the ion temperature, Ti, evaluated from Doppler broadening of a He II line emission at 468.6 nm is found to increase toward the surface, but also does not depend on Vb. Possible mechanisms of the Te and Ti rise as well as validity of the line intensity ratio technique near the material surface are discussed.

DOI10.1016/j.jnucmat.2014.10.083
Division

PSI

Department

PSI-E

PID

4a740a3caccb4311b0a5a70db1dd5342

Alternate TitleJ. Nucl. Mater.

Go back one page.