Alignment creation and deviation from statistical population distribution in hydrogen =3 levels observed on MSE spectra of LHD plasma

Iwamae, Atsushi; Sakaue, Atsushi*; Atake, Makoto*; Sawada, Keiji*; Goto, Motoshi*; Morita, Shigeru*

Plasma Physics and Controlled Fusion, 51(11), p.115004_1 - 115004_15, 2009/11

https://doi.org/10.1088/0741-3335/51/11/115004

Modification of tomography technique for two-dimensional spectroscopic measurement in JT-60U divertor plasmas

Fujimoto, Kayoko; Nakano, Tomohide; Kubo, Hirotaka; Sawada, Keiji*; Takizuka, Tomonori; Shimizu, Katsuhiro; Kawashima, Hisato; Asakura, Nobuyuki

Plasma and Fusion Research (Internet), 2, p.S1121_1 - S1121_4, 2007/11

https://doi.org/10.1585/pfr.2.S1121

Understanding deuterium particle behavior in the divertor plasma is necessary to study the ionizing and recombining plasmas. Two-dimensional spectroscopic measurement of deuterium emission is useful to understand deuterium particle behavior in divertor plasmas. The information of the ionization and recombination can be obtained by measurement of deuterium Balmer-series lines. A wide-spectral-band spectrometer with a CCD detector was used to observe deuterium Balmer-series lines with two-dimensional spatial distribution in the JT-60U divertor region. From the measurement, we can obtain a two-dimensional distribution of D and D using a computer tomography technique. The D emission was strong above the strike point in the inner divertor and around the strike point in the outer divertor. The D emission was strong above the strike point in the inner divertor.

Divertor spectroscopy with molecular transport

Kubo, Hirotaka; Takenaga, Hidenobu; Nakano, Tomohide; Higashijima, Satoru; Shimizu, Katsuhiro; Sawada, Keiji*; Kobayashi, Shinji*; JT-60 Team

Nuclear Fusion Research; Springer Series in Chemical Physics, Vol.78, p.121 - 134, 2004/11

no abstracts in English

Volume recombination in divertor plasmas

Kubo, Hirotaka; Sawada, Keiji*

Purazuma, Kaku Yugo Gakkai-Shi, 74(6), p.562 - 567, 1998/06

https://ci.nii.ac.jp/naid/110003826226

no abstracts in English

Two-dimensional structure of volume recombination in JT-60U detached divertor plasmas

Fujimoto, Kayoko; Nakano, Tomohide; Kubo, Hirotaka; Sawada, Keiji*; Takizuka, Tomonori; Kawashima, Hisato; Shimizu, Katsuhiro; Asakura, Nobuyuki

no journal, , 

The volume recombination in detached divertor plasmas is a key process to reduce the ion flux to the divertor plates. The deuterium Balmer-series lines (D, D, ..., D) from a detached divertor plasma were observed two-dimensionally with a spatial resolution of about 1 cm and were reconstructed with a tomography technique. The ratio of the D to the D emissivity was compared to that calculated by the collisional-radiative model. This ratio could not be explained only by the excitation of D by electron impact, indicating that the volume recombination contributed to the D emission. This is the case for the region above the inner strike point with about 8 cm and 4 cm, respectively, in the r- and the z-direction on the poloidal cross-section. In this region, from the ratios of the D, D, ..., D emissivities, the electron density and temperature were evaluated to be about 110 m and less than 0.3 eV, respectively.

Generation and characterization of detached plasma in the GAMMA 10/PDX end-cell

Nakashima, Yosuke*; Ichimura, Kazuya*; Takeda, Hisahito*; Iwamoto, Miki*; Hosoda, Yasunari*; Shimizu, Keita*; Oki, Kensuke*; Sakamoto, Mizuki*; Ono, Noriyasu*; Kado, Shinichiro*; et al.

no journal, , 

no abstracts in English