Plasma and Fusion Research

Volume 4, 025 (2009)

Regular Articles

Spatial Structure of Volume Recombination in JT-60U Detached Divertor Plasmas

Kayoko FUJIMOTO, Tomohide NAKANO, Hirotaka KUBO, Keiji SAWADA¹⁾, Tomonori TAKIZUKA, Hisato KAWASHIMA, Katsuhiro SHIMIZU and Nobuyuki ASAKURA

Japan Atomic Energy Agency, Ibaraki 311-0193, Japan
1): Shinshu University, Nagano 380-8553, Japan

(Received 9 March 2009 / Accepted 8 April 2009 / Published 4 June 2009)

Abstract

Two-dimensional distributions of D_α, D_β, D_γ and D_δ are reconstructed from line-integral measurements. The two-dimensional emission ratio of D_δ to D_γ indicates that the volume recombination occurs throughout the inner divertor plasma. In particular, at an emission peak above the inner strike point, it is shown that the population density of high n levels (n = 4, 5 and 6) is determined by the electron-ion volume recombination with an electron temperature and density of 0.2-0.5 eV and 1 × 10²⁰ m^-3 , respectively, and that the population density of the n=3 level is not explained by the recombining plasma component with or without the ionizing plasma component.

Keywords

divertor detachment, volume recombination, tomography, spectroscopic measurement, collisional-radiative model, JT-60U

DOI: 10.1585/pfr.4.025

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Publisher's Note

This article was based on the invited talk at the 24th JSPF Annual Meeting (2007, Himeji). This information has been added to the footnote in the article. [13 Jul. 2009]

This paper may be cited as follows:

Kayoko FUJIMOTO, Tomohide NAKANO, Hirotaka KUBO, Keiji SAWADA, Tomonori TAKIZUKA, Hisato KAWASHIMA, Katsuhiro SHIMIZU and Nobuyuki ASAKURA, Plasma Fusion Res. 4, 025 (2009).