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)'
[email protected]
1.5
-2
e
e
0.5
0
H
0.2
-0.5
0
e
0.4
19
-3
0.6
e
0.8
Ip
-1
0
1
0065139E_CNPA
5
4
10
3
4
time(s)
-60kA> Ip >-130kA
1000
Counts
2
0.000 s - 0.486 s (Ip = 0 kA)
0.486 s - 0.972 s (Ip=-5kA)
0.972 s - 1.458 s (Ip=-35kA)
1.458 s - 1.944 s (Ip=-60 kA)
1.944 s - 2.430 s (Ip=-90kA)
2.430 s - 2.916 s (Ip=-100kA)
2.916 s - 3.402 s (Ip=-110kA)
3.402 s - 3.888 s (Ip=-120 kA)
3.888 s - 4.374 s (Ip=-125kA)
4.374 s - 4.860 s (Ip=-130kA)
4.860 s - 5.346 s (Ip=-115kA)
10
100
10
1
0.1
By P. Goncharov)
0
Magnetic
Probes
19
1
<n >(10 m ), n L(10
Ip(MA), H(a.u.)
<n >
nL
1
m )
1.2
50
100
150
200
5
6
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
, 'nL(3849)',
'nL(3939)'
, 'nL(4029)'
, 'nL(4119)'
, 'nL(4209)'
<beta_dia>(%)
,'Halph(ImpMon)'
Ip(kA)
'NBI1(Iacc)'
, 'NBI2(Iacc)'
, 'NBI3(Iacc)'
, 'NBI4(Iacc)'
ne_1836ms
ne_2436ms
ne_2936ms
ne_2236ms
TS057851_1836ms
2000
250
0
Enh. Loss
by CO-NB
200
1500
-20
1000
100
-60
0.5
-2
500
e
150
n (a.u.)
Te(eV)
-40
Ip(kA)
19
1
e
m ) <n L>(10
Te(eV)_1836ms
Te(eV)_2436ms
Te(eV)_2936ms
Te(eV)_2236ms
[email protected] 8:17:58 2005/10/22
1.5
-3
m ), H(a.u.)
'ne_bar(3759)'
, 'nL(3309)'
, 'nL(3399)'
, 'nL(3489)'
, 'nL(3579)'
, 'nL(3669)',
'nL(3759)'
50
e
n L(10
19
-80
0
0
0.5
1
1.5 2 2.5
time(s)
3
3.5
4
-100
0
2500
3000
3500
4000
R(mm)
4500
0
5000
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
 RSAETAE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]
0.025
0.02
0.015
0.01
0.005
0
0
1
2
ne
3
-1
[x10
4
-19 3
m ]
5
Energy(NPA Spectra) [keV]
Energy Decay Time of
Increased Neutral Flux [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]
LHD#47645 @ t=0.56-0.6[s]
0.025
Redistribution of
Energetic
Particles by TAE
se
 /2 [sec.]
0.02
0.015
Energy Decay Time
of the "Hole"
0.01
0.005
0
Energy Decay Time of the "Peak"
0
0.2
0.4
0.6
<r/a>
orbit
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
Time (ms)
-8
89
TAE
EPM
m/n=3/2
core-localized
Fluctuation amplitude
~
B (T)
H (a.u.) LIP (a.u.)
Frequency (kHz)
2
m-3
Fast ion loss rate
to probe (a.u.)
ne
x1019
Enlarged pulse t = 87-89 ms
dB/dt (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 )
TAE mode having higher fluctuation level
M. Isobe et al. 9th IAEA
TM on EP, 2005, Takayama
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
130
Time (ms)
140
150
2
Fast ion loss rate
to probe (a.u.)
TAE
0
-2
1
-4
-6
0
-8
130 132 134 136 138 140 142
Time (ms)
dB/dt (a.u.)
2
120
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.
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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