1997 Fiscal Year Annual Research Report

プラズマ内部磁場揺動測定のためのモード変換散乱法の確立

Research Project

Project/Area Number	09680453
Research Category	Grant-in-Aid for Scientific Research (C)
Research Institution	University of Tsukuba
Principal Investigator	間瀬淳筑波大学, 物理工学系, 助教授 (00023325)
Co-Investigator(Kenkyū-buntansha)	北條仁士筑波大学, 物理学系, 助教授 (30116660) 市村真筑波大学, 物理工学系, 助教授 (10151482)
Keywords	マイクロ波 / 磁場揺動 / Cross-Polarization Scattering / ブラッグ条件 / プラズマ診断 / ブラズマ輸送
Research Abstract	1.周波数8-18GHz帯で動作する周波数掃引型送受信機二台により、ガンマ10セントラル部上下対向ポートおよび水平ポートにおいて、モード変換散乱(Cross-Polarization Scattering:CPS)および反射計測定を行った。送受信ホーンとして双モード広帯域ホーンを用いることにより、正常波(O)および異常波(X)モードの分離が可能となり、CPSおよび反射計の同時測定に成功した。 2.本システムをセントラル部プラズマのイオンサイクロトロン周波数領域(ICRF)の波動およびドリフト周波数領域の低周波・長波長不安定性の測定に適用し、磁気プローブ等とのクロスチェックから以下の結果を得た。 (1)ICRF領域の電磁プラズマ波、アルフベン・イオンサイクロトロン(AIC)モードの時間・空間的振る舞いを観測し、AIC不安定性の励起に起因する端損失の増加を実証した。 (2)低周波モードの測定に対するCPSおよび反射計信号スペクトルの比較より、CPS信号は0-X(X-0)モード変換を受けており、波数に関するブラッグの条件を満足していることが確認された。また、CPS信号の散乱角依存性を初めて測定し、低周波波動が磁場揺動を含んだ電磁ドリフト波の分散式に従うことを示した。 (3)CPS装置により、プラズマのベータ値の増加に従い、AIC不安定性の隣接モードの差周波数に対応する低周波波動の励起を観測した。これは両者の非線形結合により生じる磁場揺動の可能性があり、ベータ値の飽和との関連も議論した。 3.プラズマ中の電磁波伝搬に関する計算機シミュレーションを行い、電磁波の透過、反射、およびモード変換散乱波の振る舞いに関する知見から、本手法および反射法の磁場揺動および密度揺動測定法としての妥当性を評価した。

Research Products

(15 results)

All Other

All Publications (15 results)

[Publications] Y.Kogi, A.Mase, et al.: "Cross-Polarization Scattering from Low-Frequency Waves in a Tandem Mirror Plasma" Japanese Journal of Applied Physics. 36・5A. L587-L589 (1997)
[Publications] L.G.Bruskin, A.Mase, et al: "Wavelet Application for Reflectometry of Plasma Density Profile" Japanese Journal of Applied Physics. 36・5B. L632-L633 (1997)
[Publications] K.Ikeda, Y.Nagayama, et al.: "Rotation of Cylindrical Plasmas in the GAMMA 10 Tandem Mirror" Physical Review Letters. 78・20. 3872-3875 (1997)
[Publications] A.Mase, M.Kobayashi, et al.: "Reflectometric Measurement of Density and Magnetic Fluctuations in ICRF-Driven Waves" Fusion Engineering and Design. 34-35. 371-374 (1997)
[Publications] N.Oyama, A.Mase, et al.: "Plasma Diagnostics Using Millimeter-Wave Two-Dimensional Imaging Array" Fusion Engineering and Design. 34-35. 407-410 (1997)
[Publications] L.G.Bruskin, A.Mase, T.Tamano: "Resolution of Microwave Correlation Reflectometry" Fusion Engineering and Design. 34-35. 441-445 (1997)
[Publications] H.Hojo, H.Honda, N.Katsuragawa, A.Mase: "Ultrashort-Pulse Microwave-Plasma Interaction and Reflectometry" Fusion Engineering and Design. 34-35. 447-450 (1997)
[Publications] T.Tokuzawa, A.Mase, et al.: "Reflectometric Density Profile Measurement Using an Ultrafast Sweep Oscillator" Fusion Engineering and Design. 34-35. 451-454 (1997)
[Publications] Y.Nakashima, M.Shoji, et al.: "Behavior of Neutral-Hydrogen and Particle Confinement on GAMMA 10 Tandem Mirror" Journal of Nuclear Materials. 241-243. 1011-1015 (1997)
[Publications] A.Kumagai, M.Ichimura, et al.: "Axial Structure of Alfven Ion Cyclotron Mode in the GAMMA 10 Tendem Mirror" Japanese Journal of Applied Physics. 36・11. 6978-6980 (1997)
[Publications] A.Mase, T.Tokuzawa, et al.: "Density Profile and Fluctuation Measurement on GAMMA 10 Using FM Reflectometer" 3rd International Workshop on Microwave Reflectometry for Fusion Plasma Diagnostics,Madrid. 11-19 (1997)
[Publications] N.Nakamura, M.Ichimura, et al.: "Excitation of the Alfven Ion Cyclotron Mode Solely by an Ion Pressure Distribution" Japanese Journal of Applied Physics. 37・1. 342-343 (1998)
[Publications] S.Kubota, T.Onuma, A.Mase, et al.: "Development of an Ultrashort-Pulse Reflectometer for Density Profile Measurements on GAMMA 10" Japanese Journal of Applied Physics. 37・3A. L300-L302 (1998)
[Publications] L.G.Bruskin, A.Mase, et al.: "Measurement of Plasma Density Using Wavelet Analysis of Microwave Reflectometry" Review of Scientific Instruments. (印刷中). (1998)
[Publications] G.Vayakis, T.Ando, et al.: "Overview of the ITER Reflectometry Diagnostics Systems" International Workshop on Experimental Fusion Reactors,Varenna(Plenum Press). (発表予定). (1998)

1997 Fiscal Year Annual Research Report

プラズマ内部磁場揺動測定のためのモード変換散乱法の確立

Principal Investigator

間瀬 淳 筑波大学, 物理工学系, 助教授 (00023325)

Research Products

[Publications] Y.Kogi, A.Mase, et al.: "Cross-Polarization Scattering from Low-Frequency Waves in a Tandem Mirror Plasma" Japanese Journal of Applied Physics. 36・5A. L587-L589 (1997)

[Publications] L.G.Bruskin, A.Mase, et al: "Wavelet Application for Reflectometry of Plasma Density Profile" Japanese Journal of Applied Physics. 36・5B. L632-L633 (1997)

[Publications] K.Ikeda, Y.Nagayama, et al.: "Rotation of Cylindrical Plasmas in the GAMMA 10 Tandem Mirror" Physical Review Letters. 78・20. 3872-3875 (1997)

[Publications] A.Mase, M.Kobayashi, et al.: "Reflectometric Measurement of Density and Magnetic Fluctuations in ICRF-Driven Waves" Fusion Engineering and Design. 34-35. 371-374 (1997)

[Publications] N.Oyama, A.Mase, et al.: "Plasma Diagnostics Using Millimeter-Wave Two-Dimensional Imaging Array" Fusion Engineering and Design. 34-35. 407-410 (1997)

[Publications] L.G.Bruskin, A.Mase, T.Tamano: "Resolution of Microwave Correlation Reflectometry" Fusion Engineering and Design. 34-35. 441-445 (1997)

[Publications] H.Hojo, H.Honda, N.Katsuragawa, A.Mase: "Ultrashort-Pulse Microwave-Plasma Interaction and Reflectometry" Fusion Engineering and Design. 34-35. 447-450 (1997)

[Publications] T.Tokuzawa, A.Mase, et al.: "Reflectometric Density Profile Measurement Using an Ultrafast Sweep Oscillator" Fusion Engineering and Design. 34-35. 451-454 (1997)

[Publications] Y.Nakashima, M.Shoji, et al.: "Behavior of Neutral-Hydrogen and Particle Confinement on GAMMA 10 Tandem Mirror" Journal of Nuclear Materials. 241-243. 1011-1015 (1997)

[Publications] A.Kumagai, M.Ichimura, et al.: "Axial Structure of Alfven Ion Cyclotron Mode in the GAMMA 10 Tendem Mirror" Japanese Journal of Applied Physics. 36・11. 6978-6980 (1997)

[Publications] A.Mase, T.Tokuzawa, et al.: "Density Profile and Fluctuation Measurement on GAMMA 10 Using FM Reflectometer" 3rd International Workshop on Microwave Reflectometry for Fusion Plasma Diagnostics,Madrid. 11-19 (1997)

[Publications] N.Nakamura, M.Ichimura, et al.: "Excitation of the Alfven Ion Cyclotron Mode Solely by an Ion Pressure Distribution" Japanese Journal of Applied Physics. 37・1. 342-343 (1998)

[Publications] S.Kubota, T.Onuma, A.Mase, et al.: "Development of an Ultrashort-Pulse Reflectometer for Density Profile Measurements on GAMMA 10" Japanese Journal of Applied Physics. 37・3A. L300-L302 (1998)

[Publications] L.G.Bruskin, A.Mase, et al.: "Measurement of Plasma Density Using Wavelet Analysis of Microwave Reflectometry" Review of Scientific Instruments. (印刷中). (1998)

[Publications] G.Vayakis, T.Ando, et al.: "Overview of the ITER Reflectometry Diagnostics Systems" International Workshop on Experimental Fusion Reactors,Varenna(Plenum Press). (発表予定). (1998)

間瀬淳筑波大学, 物理工学系, 助教授 (00023325)