The polarization of electron cyclotron emission spectra in the Large Helical Device

P. C. De Vries; K. Kawahata; Y. Nagayama; H. Sasao; S. Inagaki; K. Nagasaki

doi:10.1063/1.1286668

The polarization of electron cyclotron emission spectra in the Large Helical Device

P. C. De Vries, K. Kawahata, Y. Nagayama, H. Sasao, S. Inagaki, K. Nagasaki

Research output: Contribution to journal › Article › peer-review

7 Citations (Scopus)

Abstract

Electron cyclotron emission (ECE) can be used to determine the electron temperature profile in magnetized plasmas. The complex structure of the magnetic field configuration in the Large Helical Device (LHD) [M. Fujiwara et al., S. Fusion Energy 15, 7 (1996)] complicates the analysis of the ECE spectrum. The magnetic field is a nonmonotonous function of the radius and has a very large shear. The effects of the magnetic-field shear on the polarization of the ECE spectrum have been numerically and experimentally analyzed. For a high enough density (n_e> 1.0×10¹⁹m^-3) the polarization is found to rotate with the sheared magnetic field, yielding only a negligible mode conversion. Experiments on the polarization have been carried out at LHD. X-mode emission was detected under a specific angle, in agreement with the numerical predictions. The elliptically polarized ECE emission showed a very strong O-mode component (70% of X-mode), that can be attributed to the effect of wall reflections.

Original language	English
Pages (from-to)	3707-3713
Number of pages	7
Journal	Physics of Plasmas
Volume	7
Issue number	9
DOIs	https://doi.org/10.1063/1.1286668
Publication status	Published - Sept 2000
Externally published	Yes

All Science Journal Classification (ASJC) codes

Condensed Matter Physics

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10.1063/1.1286668

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title = "The polarization of electron cyclotron emission spectra in the Large Helical Device",

abstract = "Electron cyclotron emission (ECE) can be used to determine the electron temperature profile in magnetized plasmas. The complex structure of the magnetic field configuration in the Large Helical Device (LHD) [M. Fujiwara et al., S. Fusion Energy 15, 7 (1996)] complicates the analysis of the ECE spectrum. The magnetic field is a nonmonotonous function of the radius and has a very large shear. The effects of the magnetic-field shear on the polarization of the ECE spectrum have been numerically and experimentally analyzed. For a high enough density (ne> 1.0×1019m-3) the polarization is found to rotate with the sheared magnetic field, yielding only a negligible mode conversion. Experiments on the polarization have been carried out at LHD. X-mode emission was detected under a specific angle, in agreement with the numerical predictions. The elliptically polarized ECE emission showed a very strong O-mode component (70% of X-mode), that can be attributed to the effect of wall reflections.",

author = "{De Vries}, {P. C.} and K. Kawahata and Y. Nagayama and H. Sasao and S. Inagaki and K. Nagasaki",

year = "2000",

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doi = "10.1063/1.1286668",

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TY - JOUR

T1 - The polarization of electron cyclotron emission spectra in the Large Helical Device

AU - De Vries, P. C.

AU - Kawahata, K.

AU - Nagayama, Y.

AU - Sasao, H.

AU - Inagaki, S.

AU - Nagasaki, K.

PY - 2000/9

Y1 - 2000/9

N2 - Electron cyclotron emission (ECE) can be used to determine the electron temperature profile in magnetized plasmas. The complex structure of the magnetic field configuration in the Large Helical Device (LHD) [M. Fujiwara et al., S. Fusion Energy 15, 7 (1996)] complicates the analysis of the ECE spectrum. The magnetic field is a nonmonotonous function of the radius and has a very large shear. The effects of the magnetic-field shear on the polarization of the ECE spectrum have been numerically and experimentally analyzed. For a high enough density (ne> 1.0×1019m-3) the polarization is found to rotate with the sheared magnetic field, yielding only a negligible mode conversion. Experiments on the polarization have been carried out at LHD. X-mode emission was detected under a specific angle, in agreement with the numerical predictions. The elliptically polarized ECE emission showed a very strong O-mode component (70% of X-mode), that can be attributed to the effect of wall reflections.

AB - Electron cyclotron emission (ECE) can be used to determine the electron temperature profile in magnetized plasmas. The complex structure of the magnetic field configuration in the Large Helical Device (LHD) [M. Fujiwara et al., S. Fusion Energy 15, 7 (1996)] complicates the analysis of the ECE spectrum. The magnetic field is a nonmonotonous function of the radius and has a very large shear. The effects of the magnetic-field shear on the polarization of the ECE spectrum have been numerically and experimentally analyzed. For a high enough density (ne> 1.0×1019m-3) the polarization is found to rotate with the sheared magnetic field, yielding only a negligible mode conversion. Experiments on the polarization have been carried out at LHD. X-mode emission was detected under a specific angle, in agreement with the numerical predictions. The elliptically polarized ECE emission showed a very strong O-mode component (70% of X-mode), that can be attributed to the effect of wall reflections.

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JO - Physics of Plasmas

JF - Physics of Plasmas

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ER -

The polarization of electron cyclotron emission spectra in the Large Helical Device

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