第2回 科研費特定領域「プラズマ燃焼のための先進プラズマ計測」シンポジウム 2006.2.16-2.18, 博多 C03-1 アルヴェン固有モード・センシングシ ステムによるアルファ粒子損失機構の研究 研究代表者 東井和夫(核融合研) 研究分担者 大舘 暁(核融合研) 研究分担者 榊原 悟(核融合研) 研究分担者 武智 学(原研) 協力研究者 磯部光孝(核融合研)、長壁正樹(核融合研)、永岡賢一(核融合研)、 徳沢季彦(核融合研)、西浦正樹(核融合研)、中島徳嘉(核融合研)、 藤堂泰(核融合研)、篠原孝司(原子力機構)、石川正男(原子力機構)、 松永 剛(原子力機構)、山本 聡( 阪大)、庄司多津男(名大)、 菊池祐介(ユーリッヒ)、D. Spong (ORNL) CHS, LHD 及び JT-60U における研究の進展 高速イオン励起MHDモード(アルヴェン固有モードAE、高エネルギー粒子モード EPMなど)の特性研究と高速イオン輸送への影響の研究を、CHS, LHD,JT-60Uさ らにTEXTORで進めている。 (A) 高速イオン励起AEとEPMの 特性研究: LHD, JT-60U LHD : 反射計によるAEの内部構造の測定 ( 徳沢, NIFS) LHD : 極低回転変換プラズマにおける高調波モードとEPM JT-60U : 負磁気シアトカマクプラズマにおけるAE(武智、JAEA) (B) アンテナ励起によるAE励起と減衰率の測定: CHS, TEXTOR CHS:外部印加の高周波磁場摂動印加によるTAE励起と減衰率測定(松永 JAEA) TEXTOR: DEDコイルによるAE 励起と減衰率測定(庄司 名大) (C) AE及びEPMによる高速イオン輸送: CHS, LHD, JT-60U CHS : 高時間分解損失イオンプローブ, 方向性プローブ等によるEPMs及び TAEs に よる高速イオン輸送の研究 ( 磯部 NIFS 、永岡 NIFS) LHD:TAEバーストによる高速イオンの径方向再分配(長壁、NIFS) JT-60U:負磁気シアトカマクプラズマにおけるAE(石川、JAEA) (E) 実験結果のコンピュータシミュレーション: CHS及びLHDの実験データ CHS 及びLHDの実験結果のコンピュータシミュレーション (D. Spong, ORNL, 藤堂, NIFS) (A)高速イオン励起AEとEPMの 特性研究: LHD, JT-60U (関連発表)徳沢(NIFS)の発表 Shear Alfvén Spectra(by CAS3D3) - Configuration 1: high magnetic shear (Rax=3.6 m, low ) Nf=1 Nf=2 C-TAE G-TAE m=2,3 m=3,4,5 We compare these observed frequencies with the global mode analyses by CAS3D3. The n=1, 2 mode are identified with core-localized TAE and global TAE, respectively. The continuum damping due to the high-n modes is quite weak in LHD. 20th IAEA FEC [EX/5-4Rb] presented by S. Yamamoto, S. Yamamoto et al., NF(2005) Measurements of internal structure of AEs by m-wave reflectometer(徳沢季彦) T. Tokuzawa et al. 9th IAEA TM on EP, 2005 Space=20points, Sweep time=0.2s Characteristic Frequency Modulation Frequency 40 Measured Range Frequency [GHz] @t=4.0s 35 30 25 f f 20 up-stair right-hand ce fluctuation level [arb.units] #57835 t= 4.0-4.8 s 1 non Reflect. #57835 Bax=1.0T Rax=3.75m NBI#1(CCW) t>2.3s Reflect. 175-220kHz 0.1 0.01 Shear Alfvén Spectra 15 0.4 0.6 0.8 1 0 0.05 0.1 0.15 0.2 time [s] PSD (<500kHz) n=1 120-170kHz 500 10 n=1 400 frequency [kHz] 0.2 fluctuation level [arb.units] 0 1 300 200 100 2 #57835 FIR 1.5 n [10 1 e 19 -3 m ] n=2 500 100 10 60-110kHz -0.6 2 2.5 3 3.5 4 time [s] 4.5 5 5.5 6 300 200 100 1 0.5 0 n=2 400 frequency [kHz] fluctuation level [arb.units] 0 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 0 0 0.2 0.4 0.6 0.8 1 'nL(3309)' , 'nL(3399)', 'nL(3489)' , 'nL(3579)' , 'nL(3669)' , 'nL(3759)' , 'nL(3849)' , 'nL(3939)' , 'nL(4029)' , 'nL(4119)' , 'nL(4209)' 'ne_bar(3759)' (5-1) Fast Ion Confinement & Energetic Ion Driven AEs/EPMs Ip(MA) ,'Halph(ImpMon)' ip@ 6 5 1 3 9 1 .5 -2 e e 0 H -0 .5 0 e 0 .4 19 -3 e 0 .5 0 .6 m ), n L (1 0 0 .8 0 .2 Ip -1 0 1 2 3 4 5 6 tim e (s ) 0.0 0 0 s - 0 .4 8 6 s (Ip = 0 k A ) 0.4 8 6 s - 0 .9 7 2 s (Ip = -5 k A ) 0.9 7 2 s - 1 .4 5 8 s (Ip = -3 5 k A ) 1.45 8 s - 1 .94 4 s (Ip = -6 0 k A) 1.9 4 4 s - 2 .4 3 0 s (Ip = -9 0 k A ) 2.4 3 0 s - 2 .9 1 6 s (Ip = -1 0 0 kA ) 2.9 1 6 s - 3 .4 0 2 s (Ip = -1 1 0 kA ) 3.4 0 2 s - 3 .8 8 8 s (Ip = -1 2 0 k A ) 3.88 8 s - 4 .37 4 s (Ip = -1 2 5 k A ) 4.3 7 4 s - 4 .8 6 0 s (Ip = -1 3 0 kA ) 4.8 6 0 s - 5 .3 4 6 s (Ip = -1 1 5 kA ) 0065139E_CNPA 10 10 5 4 -6 0 k A > Ip > -1 3 0 kA 1000 C o u n ts Magnetic Probes 19 1 < n > (1 0 Ip (M A ), H (a .u .) <n > n L 1 m ) 1 .2 100 10 1 By P. Goncharov) 0 .1 0 50 100 150 200 No change in energy spectra of charge exchanged fast neutrals (by P. Gocharov) Observation of multiple higher harmonics in AE/EPM frequency range This may be a new type of AEs Interferometry Excitation of Energetic Particle Modes with Co-NBI 'ne_bar(3759)' , 'nL(3309)' , 'nL(3399)' , 'nL(3489)' , 'nL(3579)' , 'nL(3669)', 'nL(3759)' , 'nL(3849)', 'nL(3939)' , 'nL(4029)' , 'nL(4119)' , 'nL(4209)' <beta_dia>(%) ,'Halph(ImpMon)' Ip(kA) 'NBI1(Iacc)' , 'NBI2(Iacc)' , 'NBI3(Iacc)' , 'NBI4(Iacc)' Te(eV)_1836ms Te(eV)_2436ms Te(eV)_2936ms Te(eV)_2236ms 2 0 00 250 0 E n h . L o ss b y C O -N B 200 1 5 00 -2 0 150 e 1 0 00 100 -6 0 0 .5 n (a.u .) T e (eV ) -4 0 Ip (k A ) 19 1 e m ) < n L > (10 T S 05 7 8 5 1 _1 8 3 6 m s 1 .5 -3 m ), H (a .u .) firca ll@ 5 7 8 5 1 8 :1 7 :5 8 2 0 05 /1 0 /2 2 ne_1836ms ne_2436ms ne_2936ms ne_2236ms -2 500 50 e n L (1 0 19 -8 0 0 0 0 .5 1 1 .5 2 2 .5 tim e (s ) 3 3 .5 4 -1 0 0 0 2500 3 0 00 3 5 00 4 0 00 45 00 0 50 0 0 R (m m ) Application of CO-NBI to a plasma with large negative Ip induces enhanced energetic ion loss caused by excited EPMs with m/n=3/1 . FIR data may give information on CONBI deposition profile, i.e., off-axis deposition. JT-60Uの負磁気シアプラズマにおけるAE 研究に進展 (武智 学) 理論:内部輸送障壁(ITB)の形成される高閉じ込めの負磁 気シアプラズマではAEは安定化。このようなプラズマのAE 研究が不十分。LHDやCHSの負磁気シア配位との共通点。 JT-60Uで負磁気シアプラズマ特有のRSAE (Reversed Shear Alfvén Eigenmodes)の観測とAEの簡易モデルの検 証を実施。 RSAE Alfven Cascade JT-60Uの負磁気シア配位 まとめと今後の課題 JT-60UのRSプラズマのAEの周波数変化は簡 便なRSAEモデルにより説明可 RSAETAEへの遷移がもっとも不安定になりやす い。 AEはqoをあげても安定化されない 種々の揺動の高速サンプルデータの収集 TASK/WMコードで周波数の時間変化の解析 RSAEの理解とITB trigger eventとの相関研究 (RSAEのqminの計測モニター) (B) アンテナ励起によるAE励起と減衰率の測定: CHS, TEXTOR (関連発表)庄司(名大)TEXTOR AE Spectroscopy System in CHS(松永) This system is composed of two electrodes. Excitation voltage is applied between vacuum vessel and electrodes. → Single probe method Excitation current is induced along a specific magnetic field line. ↓ Shear Alfvén waves would Toroidal Mode → Even Mode Excitation Circuit Bipolar Power Supply (HSA4014) Function Generator 9th IAEA Technical Meeting on EPs, 2005, Takayama by G. Matsunaga, G. Matsunaga et al., PRL (2005) Electrode Current Coaxial Cable Monitor Voltage Monitor GPIB-ENET/100 be effectively generated. Ethernet Timing Trigger Plasma PC in Control Room Vacuum Vessel Electrode Profiles of Transfer Functions 10 20 2mm Interferometer 0 1st Sweep 0 12 6 1 12 2nd Sweep 0 3rd Sweep 1.5(1.5) Electorode position Re 0.0(0.725) 6 1 12 Im 6 1 0 Abs -1.5(0.0) 100 200 300 400 500 Time[ms] 9th IAEA Technical Meeting on EPs, 2005, Takayama by G. Matsunaga, Re ,Im (Abs )[T/(As )] Transfer function can be obtained as complex function of frequency and position. The transfer functions clearly show eigenmode at r/a ~ 0.5 and f ~ 100kHz. Channel Electrode Position Resonance (r/a=0.70) Channe l ch.1 Langmuir Probe LP = 1.0) 200 Channe l ch.6 40 Te [e V] ch.12 Fe x[kHz] n e [10 16 m -3 ] Magnetic Probe Array Eigen-frequency & Damping rate 1st Sweep(t=40-180) 1.50 Abs ne 0.00 To confirm that these modes are related to AEs, plasma parameter were varied. Re -1.50 VA[106 m/s] 1.50 6 He H Ne 2nd Sweep(t=200-340) 0.00 4 2 -1.50 3rd Sweep(t=360-500) 1.50 0.00 -1.50 0 100 200 Fex[kHz] 9th IAEA Technical Meeting on EPs, 2005, Takayama by G. Matsunaga, Damping Rate[%] Transfer Function[T/(As) Im 0 100 10 1 0 100 200 fobs[kHz] 300 The observed frequency clearly depends on VA.---AEs Damping rates are about 5 ~ 20%. Damping rates v.s. Ve/VA Electron pressure converts shear Alfvén wave into kinetic Alfvén wave in the range of Ve >VA. It is expected that radiative damping can be effective with increasing Te. Damping Rate[%] KAW propagates away from AE gap and is damped by Landau damping. → Radiative Damping 30 20 He H Ne Continuum Damp. 10 Continuum + Radiative Damp. 0 0.1 1 Ve/VA 10 In the range of Ve >VA, the damping Conditions 0.1<Ve/VA<8 are realized. rates become larger. ↓ Radiative Damping may be a possible 9th IAEA Technical Meeting on EPs, candidate of damping mechanisms. 2005, Takayama by G. Matsunaga, TEXTORのDEDコイルを用いたAE励起実験 (庄司、名大) m/n=3/1, 6/2及び12/3のq=3に共鳴するヘリ カル磁場を印加できるDynamic Ergodic Divertor(DED)コイルに1-500kHzの微小高 周波電流を流し、その等価的インピーダンス を計測し、AEの探索を行った。 詳細発表:2月18日 T. Shoji et al.9th IAEA TM on EP, 2005, Takayama LHD, CHS 及びJT-60Uにおける高速 イオン励起AE及びEPMによる高速イ オン輸送 (関連発表)磯部光孝 (関連発表)永岡賢一 Modulation of Fluxes of Charge Exchanged Fast Particles by Bursting TAEs on LHD(長壁正樹) Energy decay time was examined from the least square fitting of the increased neutral flux peak position to the exponential function . dW/dt [kW] Energy decay time of increased neutral flux was proportional to 1/ne, indicating the increase observed at the lower energy side was due to LHD/31219 the classical slowing down process. Freq.(PSD) [kHz] 0.0 25 0 .02 0.0 15 0 .01 0.0 05 0 0 1 2 n 3 -1 e [ x1 0 -19 4 3 m ] 5 Energy(NPA Spectra) [keV] Ene rg y D ec ay Ti me of Incre ased Neutr al Fl ux [s ] 0 .03 1000 0.4 800 0.2 600 0.0 400 -0.2 200 -0.4 0 150 -0.6 B q [a.u.] M. Osakabe et al.9th IAEA TM on EP, 2005, Takayama 100 50 0 200 6x10 3 150 4x10 100 50 0 0.55 2x10 0.60 0.65 time [s] 0.70 0.75 3 3 Relation between TAE gap and Particle Orbit M. Osakabe et al. 9th IAEA TM on EP, 2005, Takayama The particle’s orbit has higher probability of staying around the TAE gap by n=2/m=3~4. LHD#31221 orbit RMS 0 -0.5 1 0.5 0 0.005 0.004 0.003 s -1 150 0.002 =2.1ms exp. ( 0.001 =4.3ms) decay (86->54keV) s 0 150 Decay Time = ~4.3ms 100 50 0 0.925 Frequency (kHz) Energy of NPA channel [keV] 3 2.5 2 1.5 0.006 Slowing Down Time of PassingParticleson NPA Sight Line: (86->54keV) [s] Mirnov [a.u.] B 0.5 LHD#31221 at t=0.94s 3.5 Radial Distribution Probability Density of Particles Circulating at <> =0.55 [1/] 1 Peak Position of Increased Neutral Flux Fitted Curve to Exponential Function 100 50 n=2/m=2~3 TAE 0 0.93 0.935 0.94 Time [s] f (m/n~2/2) n=2/m=3~4 0.945 0.95 0.955 0 0.2 0.4 0.6 , <> orbit 0.8 1 Clump and Hole Formation in NPA Spectra Creation of a ‘Peak’ and a ‘Hole’ with a TAE-burst is simultaniously observed on NPA spectra. The ‘hole’ starts from 153keV( and can be extrapolated to 180keV at the burst timing) and its typical decay time is 8.3[ms] The ‘peak’ starts from 153keV and its decay time is 6[ms] L H D # 4 76 4 5 @ t= 0 .5 6 -0.6 [s ] 0 .0 2 5 Redistribution of Energetic Particles by TAE 0 .0 1 5 E n e rg y D e c a y T im e o f th e "H o le " 0 .0 1 se /2 [s e c .] 0 .0 2 0 .0 0 5 E n e rg y D e c a y T im e o f th e "P e a k " 0 0 0 .2 0 .4 < r/a > 0 .6 or bit 0 .8 1 M. Osakabe et al. 9th IAEA TM on EP, 2005, Takayama M. Isobe et al. 9th IAEA TM on EP, 2005, Takayama Lost fast ion probe signals measured at large R side(磯部光孝) - Bright spot on the scintillator screen due to impact of fast ions - Pitch angle (degrees) 100 EPM-quiescent phase t=74-75 ms 110 120 Co-, parallel 130 135 145 140 1.5 2.0 2.5 3.0 3.5 4.0 5.0 m/n=3/2 LIP Primary spot 6.0 H 100 70 75 80 85 Time (ms) 90 EPM phase t=85-86 ms -Primary loss spot appears in pitch angle of 130~133 degrees (v///v= -0.64 ~ -0.68). - Measured gyro-radius is consistent with that of ions having Eb. -During EPM, scintillation light intensity in more parallel pitch angle significantly increases. 110 120 Perp. 130 135 145 140 1.5 2.0 2.5 3.0 3.5 4.0 5.0 6.0 Gyroradius centroid (cm) Frame rate : 1 kHz Gyroradius centroid (cm) Frequency (kHz) dB/dt shot#122764 Rax/Bt=0.974 m/0.92 T TAE mode and its effect on beam ions -Toroidal Alfvén eigen (TAE) mode is excited by tangentially coinjected NB. - Weak TAE appears between the two pulses. 2 1 dB/dt 0 0 TAE 1 -2 EPM -4 -6 0 87 m/n=2,3/1 87.5 88 88.5 -8 89 Time (ms) TAE EPM m/n=3/2 core-localized Fluctuation amplitude ~ B (T) H (a.u.) LIP (a.u.) Frequency (kHz) 2 m-3 F a s t io n lo s s ra te to p ro b e (a .u .) ne x1019 Enlarged pulse t = 87-89 ms d B /d t (a .u .) 2 shot#124870 Rax/Bt=96.2cm/0.91T M. Isobe et al. 9th IAEA TM on EP, 2005, Takayama Amplitude ~ 1x10-5 T Time (ms) Time (ms) - Significant increase of fast ion loss is not seen when the mode amplitude is small (~1x10-5T ) M. Isobe et al. 9th IAEA TM on EP, 2005, Takayama TAE mode having higher fluctuation level shot#124870 Rax/Bt=96.2cm/0.91T ~ B (T) TAE's level gradually decreasing Comparison on beam ion losses between EPM and TAE 3 EPM:shot#124866, 124868 TAE:shot#124870 110 120 130 Time (ms) 150 2 F as t io n lo s s ra te to p ro b e (a.u .) TAE 0 -2 1 -4 -6 0 -8 130 132 134 136 138 140 142 Time (ms) d B /d t (a .u .) 2 140 fastion (a.u .) amplitude :(3-4)x10-5 T 2 TAE 1 EPM 0 0 5 10 ~ B (x10 -5 T) 15 -Fast ion loss due to TAE mode appears when fluctuation level is above 3x10-5 T and rapidly increases as fluctuation level increases. JT-60UにおけるAEによる高速イオン輸送 (石川正男) M. Ishikawa et al.9 IAEA TM on th EP, 2005, Takayama M. Ishikawa et al.9th IAEA TM on EP, 2005, Takayama M. Ishikawa et al.9th IAEA TM on EP, 2005, Takayama M. Ishikawa et al.9th IAEA TM on EP, 2005, Takayama DELTA5DによるCHSにおけるEPM誘起 イオン輸送のシミュレーション ( D.A. Spong, ORNL) DELTA5D: 1.Orbit equation+Monte Carlo code 2.Modeled magnetic perturbations of which frequency chirping is simulated from experimental data. Preliminary results of the numerical simulation(1) Preliminary results of the numerical simulation(2) Conclusion and Next Steps H18年度計画の概要 CHS: 1.新たにファラデーカップ付損失イオンプローブ、高速H検出器アレイの新設による 高速イオン計測データの充実。損失イオンプローブ(LFS, HFS), 方向性プローブ 2.周辺挿入電極方式による高周波摂動磁場と損失イオンプローブ信号との相関計測 LHD: 1.AEのアンテナ励起と減衰率計測(MP、SX,ECE,反射計、干渉計との相関) 2.反射計などによる高速イオン励起AEの空間構造計測 3.NPA,ファラデーカップ付損失イオンプローブ、高速H検出器アレイ等に よる損失高速イオンデータの充実 JT-60U: 1.負磁気シアはいいでのRSAEの内部構造計測とRSAEによる高速イオン輸送 2.ICRFアンテナを利用した直接励起 理論・シミュレーションとの比較 1.DELTA5D、MEGAコードによるコンピュータシミュレーション CHSデータ: 揺動のFrequency chirpingと損失機構 LHDデータ:EPM, Bursting TAEによる高速イオン輸送 予備資料 A system for AE spectroscopy on LHD Vc=150V, I=5A, f< 1MHz Two exciter coils of 1.2mx0.5m are placed away from 180°in the toroidal direction. Then, n=0,1 and 2 are expected.