Berlin 2001 – scientific programme

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P: Plasmaphysik

P 12: Plasma Wall Interaction, Diagnostic and Low Temperature Discharges (Poster Session)

P 12.6: Poster

Friday, April 6, 2001, 12:30–15:00, AT2

Spectra of O II in the boundary plasma of TEXTOR-94 — •D. Borodin^1,2, I. Beigman², L. Vainshtein², A. Pospieszczyk¹, and S. Brezinsek¹ — ¹Institut für Plasmaphysik, Forschungszentrum Jülich GmbH, EURATOM Assoziation, Trilateral Euregio Cluster, D-52425, Jülich, Germany — ²P.N.Lebedev Institute RAS, Russia, 117924, Leninski pr. 53, Moscow, Russia

Spectra of the O II ion after injection of oxygen through a block of the upper poloidal limiter of TEXTOR-94 into the boundary plasma were obtained. As the observation system provides spatial resolution, radial profiles of measured spectral lines can be registered. The different wavelength regions were observed during reproducible TEXTOR-94 discharges with n_e = 10¹² cm⁻³, T_e= 60eV at the last closed flux surface. For calibration purposes the oxygen emission was in all discharges simultaneously registered by a 2D camera in the light of an O II line at 4415Å. Three wavelength regions were investigated: 4660± 100Å, 4340± 100Å, 3730± 100Å. Radial intensity distributions of lines corresponding to transitions 2p²[³P]3s−2p²[³P]3p (components of the multiplets ⁴P− ⁴S, ⁴P − ⁴P, ⁴P− ⁴D, ²P− ²D) and 2p²[¹D]3s−2p²[¹D]3p (doublet ²D-²D) were measured. An appropriate collisional-radiative model (atomic database and the corresponding level list) was developed and calculations using the GKU kinetic code developed at the P.N.Lebedev Institute were carried out. A comparison of the theoretical and experimental data is presented. A mechanism of the population of the metastable states of O II is discussed.