Edge and core impurity transport study with spectroscopic instruments in LHD

Shigeru Morita, Motoshi Goto, Masahiro Kobayashi, Sadatsugu Muto, Malay Bikas Chowdhuri, Chunfeng Dong, Hangyu Zhou, Zhengying Cui Zhengying, Keisuke Fujii, Akihiro Furuzawa, Masahiro Hasuo, Atsushi Iwamae, Yinxian Jie, Mohammed Koubiti, Ikuya Sakurai, Yuzuru Tawara, Baonian Wan, Zhenwei Wu, Naohiro Yamaguchi

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Impurity transport was investigated at both edge and core regions in large helical device (LHD) with developed spectroscopic instruments which can measure one- and two-dimensional distributions of impurities. The edge impurity behavior was studied recently using four carbon resonant transitions in different ionization stages of CIII (977Å), CIV (1548Å), CV (40.3Å) and CVI (33.7Å). When the line-averaged electron density, n e , is increased from 1 to 6 × 10 13 cm -3 , the ratio of (CIII+CIV)/n e increases while the ratio of (CV+CVI)/n e decreases. Here, CIII+CIV (CV+CVI) expresses the sum of CIII (CV) and CIV (CVI) intensities. The CIII+CIV indicates the carbon influx and the CV+CVI indicates the emissions through the transport in the ergodic layer. The result thus gives experimental evidence on the impurity screening by the ergodic layer in LHD, which is also supported by a three-dimensional edge particle simulation. The core impurity behavior is also studied in high-density discharges (n e ≤ 1× 10 15 cm -3 ) with multi H 2 -pellets injection. It is found that the ratio of V/D (V: convection velocity, D: diffusion coefficient) decreases after pellet injection and Z eff profile shows a flat one at values of 1.1∼1.2. These results confirm no impurity accumulation occurs in high-density discharges. As a result, the iron density, n Fe , is analyzed to be 6 × 10 -7 ( n Fe /n e ) of which the amount can be negligible as radiation source even in such high-density discharges. One- and two-dimensional impurity distributions from space-resolved VUV and EUV spectrometers newly developed for further impurity transport study are also presented with their preliminary results.

Original languageEnglish
Pages (from-to)402-408
Number of pages7
JournalPlasma Science and Technology
Volume11
Issue number4
DOIs
Publication statusPublished - 11-12-2009
Externally publishedYes

Fingerprint

chemical vapor infiltration
impurities
pellets
injection
carbon
radiation sources
convection
screening
diffusion coefficient
spectrometers
iron
ionization
profiles
simulation

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

Cite this

Morita, S., Goto, M., Kobayashi, M., Muto, S., Chowdhuri, M. B., Dong, C., ... Yamaguchi, N. (2009). Edge and core impurity transport study with spectroscopic instruments in LHD. Plasma Science and Technology, 11(4), 402-408. https://doi.org/10.1088/1009-0630/11/4/07
Morita, Shigeru ; Goto, Motoshi ; Kobayashi, Masahiro ; Muto, Sadatsugu ; Chowdhuri, Malay Bikas ; Dong, Chunfeng ; Zhou, Hangyu ; Cui Zhengying, Zhengying ; Fujii, Keisuke ; Furuzawa, Akihiro ; Hasuo, Masahiro ; Iwamae, Atsushi ; Jie, Yinxian ; Koubiti, Mohammed ; Sakurai, Ikuya ; Tawara, Yuzuru ; Wan, Baonian ; Wu, Zhenwei ; Yamaguchi, Naohiro. / Edge and core impurity transport study with spectroscopic instruments in LHD. In: Plasma Science and Technology. 2009 ; Vol. 11, No. 4. pp. 402-408.
@article{19f51dfa89374f91bae353c53e248fab,
title = "Edge and core impurity transport study with spectroscopic instruments in LHD",
abstract = "Impurity transport was investigated at both edge and core regions in large helical device (LHD) with developed spectroscopic instruments which can measure one- and two-dimensional distributions of impurities. The edge impurity behavior was studied recently using four carbon resonant transitions in different ionization stages of CIII (977{\AA}), CIV (1548{\AA}), CV (40.3{\AA}) and CVI (33.7{\AA}). When the line-averaged electron density, n e , is increased from 1 to 6 × 10 13 cm -3 , the ratio of (CIII+CIV)/n e increases while the ratio of (CV+CVI)/n e decreases. Here, CIII+CIV (CV+CVI) expresses the sum of CIII (CV) and CIV (CVI) intensities. The CIII+CIV indicates the carbon influx and the CV+CVI indicates the emissions through the transport in the ergodic layer. The result thus gives experimental evidence on the impurity screening by the ergodic layer in LHD, which is also supported by a three-dimensional edge particle simulation. The core impurity behavior is also studied in high-density discharges (n e ≤ 1× 10 15 cm -3 ) with multi H 2 -pellets injection. It is found that the ratio of V/D (V: convection velocity, D: diffusion coefficient) decreases after pellet injection and Z eff profile shows a flat one at values of 1.1∼1.2. These results confirm no impurity accumulation occurs in high-density discharges. As a result, the iron density, n Fe , is analyzed to be 6 × 10 -7 ( n Fe /n e ) of which the amount can be negligible as radiation source even in such high-density discharges. One- and two-dimensional impurity distributions from space-resolved VUV and EUV spectrometers newly developed for further impurity transport study are also presented with their preliminary results.",
author = "Shigeru Morita and Motoshi Goto and Masahiro Kobayashi and Sadatsugu Muto and Chowdhuri, {Malay Bikas} and Chunfeng Dong and Hangyu Zhou and {Cui Zhengying}, Zhengying and Keisuke Fujii and Akihiro Furuzawa and Masahiro Hasuo and Atsushi Iwamae and Yinxian Jie and Mohammed Koubiti and Ikuya Sakurai and Yuzuru Tawara and Baonian Wan and Zhenwei Wu and Naohiro Yamaguchi",
year = "2009",
month = "12",
day = "11",
doi = "10.1088/1009-0630/11/4/07",
language = "English",
volume = "11",
pages = "402--408",
journal = "Plasma Science and Technology",
issn = "1009-0630",
publisher = "IOP Publishing Ltd.",
number = "4",

}

Morita, S, Goto, M, Kobayashi, M, Muto, S, Chowdhuri, MB, Dong, C, Zhou, H, Cui Zhengying, Z, Fujii, K, Furuzawa, A, Hasuo, M, Iwamae, A, Jie, Y, Koubiti, M, Sakurai, I, Tawara, Y, Wan, B, Wu, Z & Yamaguchi, N 2009, 'Edge and core impurity transport study with spectroscopic instruments in LHD', Plasma Science and Technology, vol. 11, no. 4, pp. 402-408. https://doi.org/10.1088/1009-0630/11/4/07

Edge and core impurity transport study with spectroscopic instruments in LHD. / Morita, Shigeru; Goto, Motoshi; Kobayashi, Masahiro; Muto, Sadatsugu; Chowdhuri, Malay Bikas; Dong, Chunfeng; Zhou, Hangyu; Cui Zhengying, Zhengying; Fujii, Keisuke; Furuzawa, Akihiro; Hasuo, Masahiro; Iwamae, Atsushi; Jie, Yinxian; Koubiti, Mohammed; Sakurai, Ikuya; Tawara, Yuzuru; Wan, Baonian; Wu, Zhenwei; Yamaguchi, Naohiro.

In: Plasma Science and Technology, Vol. 11, No. 4, 11.12.2009, p. 402-408.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Edge and core impurity transport study with spectroscopic instruments in LHD

AU - Morita, Shigeru

AU - Goto, Motoshi

AU - Kobayashi, Masahiro

AU - Muto, Sadatsugu

AU - Chowdhuri, Malay Bikas

AU - Dong, Chunfeng

AU - Zhou, Hangyu

AU - Cui Zhengying, Zhengying

AU - Fujii, Keisuke

AU - Furuzawa, Akihiro

AU - Hasuo, Masahiro

AU - Iwamae, Atsushi

AU - Jie, Yinxian

AU - Koubiti, Mohammed

AU - Sakurai, Ikuya

AU - Tawara, Yuzuru

AU - Wan, Baonian

AU - Wu, Zhenwei

AU - Yamaguchi, Naohiro

PY - 2009/12/11

Y1 - 2009/12/11

N2 - Impurity transport was investigated at both edge and core regions in large helical device (LHD) with developed spectroscopic instruments which can measure one- and two-dimensional distributions of impurities. The edge impurity behavior was studied recently using four carbon resonant transitions in different ionization stages of CIII (977Å), CIV (1548Å), CV (40.3Å) and CVI (33.7Å). When the line-averaged electron density, n e , is increased from 1 to 6 × 10 13 cm -3 , the ratio of (CIII+CIV)/n e increases while the ratio of (CV+CVI)/n e decreases. Here, CIII+CIV (CV+CVI) expresses the sum of CIII (CV) and CIV (CVI) intensities. The CIII+CIV indicates the carbon influx and the CV+CVI indicates the emissions through the transport in the ergodic layer. The result thus gives experimental evidence on the impurity screening by the ergodic layer in LHD, which is also supported by a three-dimensional edge particle simulation. The core impurity behavior is also studied in high-density discharges (n e ≤ 1× 10 15 cm -3 ) with multi H 2 -pellets injection. It is found that the ratio of V/D (V: convection velocity, D: diffusion coefficient) decreases after pellet injection and Z eff profile shows a flat one at values of 1.1∼1.2. These results confirm no impurity accumulation occurs in high-density discharges. As a result, the iron density, n Fe , is analyzed to be 6 × 10 -7 ( n Fe /n e ) of which the amount can be negligible as radiation source even in such high-density discharges. One- and two-dimensional impurity distributions from space-resolved VUV and EUV spectrometers newly developed for further impurity transport study are also presented with their preliminary results.

AB - Impurity transport was investigated at both edge and core regions in large helical device (LHD) with developed spectroscopic instruments which can measure one- and two-dimensional distributions of impurities. The edge impurity behavior was studied recently using four carbon resonant transitions in different ionization stages of CIII (977Å), CIV (1548Å), CV (40.3Å) and CVI (33.7Å). When the line-averaged electron density, n e , is increased from 1 to 6 × 10 13 cm -3 , the ratio of (CIII+CIV)/n e increases while the ratio of (CV+CVI)/n e decreases. Here, CIII+CIV (CV+CVI) expresses the sum of CIII (CV) and CIV (CVI) intensities. The CIII+CIV indicates the carbon influx and the CV+CVI indicates the emissions through the transport in the ergodic layer. The result thus gives experimental evidence on the impurity screening by the ergodic layer in LHD, which is also supported by a three-dimensional edge particle simulation. The core impurity behavior is also studied in high-density discharges (n e ≤ 1× 10 15 cm -3 ) with multi H 2 -pellets injection. It is found that the ratio of V/D (V: convection velocity, D: diffusion coefficient) decreases after pellet injection and Z eff profile shows a flat one at values of 1.1∼1.2. These results confirm no impurity accumulation occurs in high-density discharges. As a result, the iron density, n Fe , is analyzed to be 6 × 10 -7 ( n Fe /n e ) of which the amount can be negligible as radiation source even in such high-density discharges. One- and two-dimensional impurity distributions from space-resolved VUV and EUV spectrometers newly developed for further impurity transport study are also presented with their preliminary results.

UR - http://www.scopus.com/inward/record.url?scp=71449085004&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=71449085004&partnerID=8YFLogxK

U2 - 10.1088/1009-0630/11/4/07

DO - 10.1088/1009-0630/11/4/07

M3 - Article

VL - 11

SP - 402

EP - 408

JO - Plasma Science and Technology

JF - Plasma Science and Technology

SN - 1009-0630

IS - 4

ER -

Morita S, Goto M, Kobayashi M, Muto S, Chowdhuri MB, Dong C et al. Edge and core impurity transport study with spectroscopic instruments in LHD. Plasma Science and Technology. 2009 Dec 11;11(4):402-408. https://doi.org/10.1088/1009-0630/11/4/07