Detection of a new parametric decay instability branch in TST-2 during high harmonic fast wave heating

Y. Adachi; A. Ejiri; Y. Takase; O. Watanabe; T. Oosako; H. Tojo; S. Kainaga; T. Masuda; M. Sasaki; J. Sugiyama; T. Yamaguchi

doi:10.1063/1.2955574

Detection of a new parametric decay instability branch in TST-2 during high harmonic fast wave heating

Y. Adachi, A. Ejiri, Y. Takase, O. Watanabe, T. Oosako, H. Tojo, S. Kainaga, T. Masuda, M. Sasaki, J. Sugiyama, T. Yamaguchi

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

5 Citations (Scopus)

Abstract

Parametric decay instability (PDI) is often observed in the TST-2 spherical tokamak during high harmonic fast wave heating by rf pickup probes. The frequency spectrum exhibits lower and upper sideband peaks in addition to the pump wave at f0 =21 MHz. Two types of PDI are observed. One is the well-known decay into the ion-cyclotron quasimode (n fci) and the ion Bernstein wave (f0 -n fci). The other is a newly found decay with the sideband frequency between f0 and f0 - fci. The frequency difference between this sideband and the pump increases in proportion to Bt. Moreover, high-speed visible light measuring systems with photomultiplier tubes or hybrid photodetectors viewing the plasma core detected oscillation of light emission at around f0.

Original language	English
Article number	10F507
Journal	Review of Scientific Instruments
Volume	79
Issue number	10
DOIs	https://doi.org/10.1063/1.2955574
Publication status	Published - 2008
Externally published	Yes

All Science Journal Classification (ASJC) codes

Instrumentation

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10.1063/1.2955574

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@article{129d19d6e8284a85b35d380310309f23,

title = "Detection of a new parametric decay instability branch in TST-2 during high harmonic fast wave heating",

abstract = "Parametric decay instability (PDI) is often observed in the TST-2 spherical tokamak during high harmonic fast wave heating by rf pickup probes. The frequency spectrum exhibits lower and upper sideband peaks in addition to the pump wave at f0 =21 MHz. Two types of PDI are observed. One is the well-known decay into the ion-cyclotron quasimode (n fci) and the ion Bernstein wave (f0 -n fci). The other is a newly found decay with the sideband frequency between f0 and f0 - fci. The frequency difference between this sideband and the pump increases in proportion to Bt. Moreover, high-speed visible light measuring systems with photomultiplier tubes or hybrid photodetectors viewing the plasma core detected oscillation of light emission at around f0.",

author = "Y. Adachi and A. Ejiri and Y. Takase and O. Watanabe and T. Oosako and H. Tojo and S. Kainaga and T. Masuda and M. Sasaki and J. Sugiyama and T. Yamaguchi",

note = "Funding Information: This work was supported by JSPF Grant-in-Aid for Scientific Research 16106013.",

year = "2008",

doi = "10.1063/1.2955574",

language = "English",

volume = "79",

journal = "Review of Scientific Instruments",

issn = "0034-6748",

publisher = "American Institute of Physics Publising LLC",

number = "10",

}

TY - JOUR

T1 - Detection of a new parametric decay instability branch in TST-2 during high harmonic fast wave heating

AU - Adachi, Y.

AU - Ejiri, A.

AU - Takase, Y.

AU - Watanabe, O.

AU - Oosako, T.

AU - Tojo, H.

AU - Kainaga, S.

AU - Masuda, T.

AU - Sasaki, M.

AU - Sugiyama, J.

AU - Yamaguchi, T.

N1 - Funding Information: This work was supported by JSPF Grant-in-Aid for Scientific Research 16106013.

PY - 2008

Y1 - 2008

N2 - Parametric decay instability (PDI) is often observed in the TST-2 spherical tokamak during high harmonic fast wave heating by rf pickup probes. The frequency spectrum exhibits lower and upper sideband peaks in addition to the pump wave at f0 =21 MHz. Two types of PDI are observed. One is the well-known decay into the ion-cyclotron quasimode (n fci) and the ion Bernstein wave (f0 -n fci). The other is a newly found decay with the sideband frequency between f0 and f0 - fci. The frequency difference between this sideband and the pump increases in proportion to Bt. Moreover, high-speed visible light measuring systems with photomultiplier tubes or hybrid photodetectors viewing the plasma core detected oscillation of light emission at around f0.

AB - Parametric decay instability (PDI) is often observed in the TST-2 spherical tokamak during high harmonic fast wave heating by rf pickup probes. The frequency spectrum exhibits lower and upper sideband peaks in addition to the pump wave at f0 =21 MHz. Two types of PDI are observed. One is the well-known decay into the ion-cyclotron quasimode (n fci) and the ion Bernstein wave (f0 -n fci). The other is a newly found decay with the sideband frequency between f0 and f0 - fci. The frequency difference between this sideband and the pump increases in proportion to Bt. Moreover, high-speed visible light measuring systems with photomultiplier tubes or hybrid photodetectors viewing the plasma core detected oscillation of light emission at around f0.

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U2 - 10.1063/1.2955574

DO - 10.1063/1.2955574

M3 - Article

C2 - 19044652

AN - SCOPUS:55349090700

SN - 0034-6748

VL - 79

JO - Review of Scientific Instruments

JF - Review of Scientific Instruments

IS - 10

M1 - 10F507

ER -

Detection of a new parametric decay instability branch in TST-2 during high harmonic fast wave heating

Abstract

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