the ecei newest experiment results on ht-7
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UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
CAS KEY LABORATORY OF BASIC PLASMA PHYSICS
The ECEI Newest Experiment Results on HT-7
报告人:徐明2008-6-2
2008-6-2
Experiment Result of ECEI on HT-7 2
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Outline Diagnostic Principles of ECEI Context knowledge
Introduction to Fluctuation of Te 2D imaging Introduction to Zonal flow
The experiment results on HT-7 2D imaging Te Fluctuations Zonal flow Muti magnetic island
Summarization
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
CAS KEY LABORATORY OF BASIC PLASMA PHYSICS
Diagnostic Principles of ECEI
2008-6-2
Experiment Result of ECEI on HT-7 4
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
The development of ECEIECEI is the abbreviation of Electron Cyclotron Emission Imaging.
1974,ECE radiometry has been developed and used for a standard diagnostic for magnetic fusion plasmas.
1993, S. Sattler and H. J. Hartfuss applied the cross-correlation technology into the Te fluctuation measurement to estimate the radiation noise and improve the sensitivity of the ECE radiometer.
1995, G. Cima and C. Watts developed another cross-correlation technology along the sight line. The use of the cross-correlation techniques solves the problem of the radiation noise.
1997, ECEI has been developed and operated on the TEXT-U.
Subsequently, RTP, TEXTOR, LHD, DIII-D etc have equipped with ECEI.
2004,ECEI have applied on HT-7.
2008-6-2
Experiment Result of ECEI on HT-7 5
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
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The Physics Principle of ECEI
2008-6-2
Experiment Result of ECEI on HT-7 6
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
2-D ECE Imaging (ECEI)
ECE measurement is an established tool for Te measurement in high temperature plasmas.
In conventional radiometry, a single antenna receives all frequencies. In ECEI, a vertically aligned antenna/mixer array employed as the receiver.
Contrasting, soft X imaging using the supposition of rotation rigid body, while ECEI can gain 2D imaging directly.
Unique advantages: High spatial and temporal resolution, 2-D correlation.
Conventional 1-D ECE System 2-D ECE Imaging System
2008-6-2
Experiment Result of ECEI on HT-7 7
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
IFIFSYSTEMSYSTEM
ElectronicsElectronicsApparatusApparatus
Imaging System
Imaging Array
System of Data Acquisition
EC
EI
EC
EI
Array
Array
LO
Frequency 99-120GHz
window
IF signals3.2-6.8GHz
LabLab ViewView
LinuxLinux
IF signals
Electrical Signal
Plasma
The Constitution of ECEI
2008-6-2
Experiment Result of ECEI on HT-7 8
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Brief Introduction to the System of Intermediate Frequency
Mixers
Power Divider
Video Amps
Input Signal
Bandpass Filters
IF Amps
Microwave Amp
LO8LO7
LO6LO5LO4
LO3LO2
LO1
Detectors
T1
T2
T3
T4
T5
T6
T7
T8
Mixers
Power Divider
Video Amps
Input Signal
Bandpass Filters
IF Amps
Microwave Amp
LO8LO7
LO6LO5LO4
LO3LO2
LO1
Detectors
T1
T2
T3
T4
T5
T6
T7
T8
Brief introduction:The signal from antenna array to the System of Intermediate Frequency and by dividing the input signal into eight channels. The output signal from the T1 to T8 is display as: 3.2,3.8,4.3,4.8,5.3,5.8,6.3,
6.8GHz.
2008-6-2
Experiment Result of ECEI on HT-7 9
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
The sample volume of ECEI The direction of poloidal
sample volume ~1.1cm Channel interval~1.3cm
The direction of radius sample length is narrow~5-6cm.
Diagnosis volume: 5.6cmx22.4cm(8x16 channels)
Time discrimination~4us
该系统噪信比量级 ~1%, 可实时研究>1%涨落 ,长时间积分研究 >0.1%涨落
The sample volume is lie on the height of window, the higher the window, the smaller of the sample volume.
The sample volume determine the magnification of lens system.
The channel interval is required bigger the sample volume and smaller the correlation length of turbulence.
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
CAS KEY LABORATORY OF BASIC PLASMA PHYSICS
Context knowledge
2008-6-2
Experiment Result of ECEI on HT-7 11
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
The knowledge of the Te fluctuation in core of plasmas
欧姆定标律 :线性区和饱和区 线性区由电子模主导 ,饱和区由离子模主导 电子模在电子逆磁漂移方向 ,离子模在离子逆磁漂移方向 ,方向正好相反 TEXT-U利用 FIR,BES观测到过高密度下 ,密度涨落中存在离子模
2008-6-2
Experiment Result of ECEI on HT-7 12
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Sawtooth reconnection model of m=1
Full magnetic reconnection model Kadomtsev(’76) Declare the core q0 drop after t
he crash q0 keep~0.7(TEXTOR & TFT
R) q0 is 0.7 ~1.0 (DIIID)
The reconnection time of theory result is fast than that of experiment results
Quasi-interchange model (R.Granets(’88))
3D local reconnection model M.Yamada(’94) Y.Nagayama(’96)
2008-6-2
Experiment Result of ECEI on HT-7 13
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
The experiment result of study m=1 mode
Results of soft X imaging sustain lots of models, sometimes self-contradictionReference:S.Yamaguchi(’04)
Results of 2-D imaging through by reconstruct 1-D ECE sustain model as follow:Ⅰfull reconnection model;Ⅱ3-D local reconnection modelExplain the asymmetry of ballooning
2008-6-2
Experiment Result of ECEI on HT-7 14
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
2D ECE imaging2D imaging of ECEI on TEXTOR
Magnetic reconnection process of full magnetic reconnection model arises in the experiments, but the process merely be possibly appear a quarter of torus
Have same characteristic of ballooning model
2008-6-2
Experiment Result of ECEI on HT-7 15
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Brief Introduction to Zonal flow
Zonal flow of Jupiter
在环形磁约束等离子体中, ZF是本征模。但它是湍流驱动的,是线性稳定的,且不直接驱动径向输运。它与漂移波湍流一起,构成漂移波—带状流系统。
P. H. Diamond et al. PPCF 47, R35 (2005)
Zonal flows, by which we mean azimuthally symmetric band-like shear flows, are a ubiquitous phenomena in nature and the laboratory.
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
CAS KEY LABORATORY OF BASIC PLASMA PHYSICS
The Experiment Results of ECEI on HT-7
The Experiment and Relative Result all disposed by Xiaoyuan Xu
2008-6-2
Experiment Result of ECEI on HT-7 17
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
The Relating Parameters of HT-7 The overall Parameters of HT-7 tokamak
R=122cm, a=27cm
The Parameters of Plasmas: Ip=170kA,Bt=1.9T,qa~3 The Radius of Surface q=1(~7cm)The Reconnection Time of Kadomtsev:
1~ ~1702k A R s
13 31.6 ~ 4.5 10 , (0) ~ 800 , ~ 0.3e pn cm Te eV
2008-6-2
Experiment Result of ECEI on HT-7 18
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Section plane of electron temperature
-15 -10 -5 0
0.2
0.25
0.3
0.35
0.4
0.45
0.5
r (cm)
Te (a
.u.)
eceecei
r (cm)
Z (c
m)
-20 -15 -10 -5 0 5-10
-8
-6
-4
-2
0
2
4
6
8
10
0.4
0.45
0.5
0.55
0.6
0.65
0.7
Radius calibration using scanning toroidal magnetic and the result in accord to the result of ECE.
Poloidal calibration through moving the equipment down and up and obtaining a perfect 2D Te section plane.
2008-6-2
Experiment Result of ECEI on HT-7 19
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
0 50 100 150 200 2500
0.5
1
1.5
2
2.5
3
/2 (kHz)
k (cm
- 1)
Er = - 6kV/m
Er = 0
(b)
0 50 100 150 200 25010
-11
10-10
10-9
/2 (kHz)
statistical noise level
(a)
Electron mode of fluctuation of Te at low density
Cross-power spectrum and spectrumlocation:r/a=0.59Poloidal interval: 2.2cmFrequency discrimination: 7.8kHz
ExB drift: edw E B
Linear frequency of electron drift wave:
* 2 2[1/(1 )]k e sk *e e nk cT eBL 1/ 2( / )s i e iT T
Electron drift wave:Electron gyration diamagnetic
Wave vector: ~ 0.3sk
k
BEk rBE
2008-6-2
Experiment Result of ECEI on HT-7 20
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
0 2 4 6 8 10 12 14
-85-80-75-70-65
H()(
dB
)
r=11.6,11.6cm =-31,31o (dr,d=-0.0,12.5cm)
0 2 4 6 8 10 12 14
0.20.40.60.8
Cohere
nt
0 2 4 6 8 10 12 14-1
0
1
Mode N
um
ber
/2 (kHz)
0 2 4 6 8 10 12 14
-90
-80
-70
H()(
dB
)
r=12.4,12.4cm =-37,37o (dr,d=-0.0,15.8cm)
0 2 4 6 8 10 12 14
0.20.40.60.8
Cohere
nt
0 2 4 6 8 10 12 14-1
0
1M
ode N
um
ber
/2 (kHz)
Poloidal interval is:12.5cm,15.8cm
For the increase of poloidal interval, the fluctuation coherence of big wave number is reduced and the trend of tend to zero is obvious.
The Experiment Result of Zonal flow——Poloidal(1)
Cross-power spectrum, coherence spectrum and number of mode
ne=1.6
poloidal wave number is perfect to be zero for frequency at 0-2kHz
2008-6-2
Experiment Result of ECEI on HT-7 21
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
0 2 4 6 8 10 12 14
-90
-80
-70
H()(
dB
)
r=11.6,11.6cm =-31,31o (dr,d=-0.0,12.5cm)
0 2 4 6 8 10 12 14
0.2
0.4
0.6
Cohere
nt
0 2 4 6 8 10 12 14-1
0
1
Mode N
um
ber
/2 (kHz)
0 2 4 6 8 10 12 14
-90
-80
-70
H()(
dB
)
r=12.4,12.4cm =-37,37o (dr,d=-0.0,15.8cm)
0 2 4 6 8 10 12 14
0.20.40.6
Cohere
nt
0 2 4 6 8 10 12 14-1
0
1
Mode N
um
ber
/2 (kHz)
The Experiment Result of Zonal flow——Poloidal(2)
ne=3.3
When the electron density is great than 3.3, characteristic of low frequency fluctuation of poloidal wave number tend to be zero is unobvious.This phenomenon may be explain that the zonal flow is damped for the strength of ion collision frequency .
Poloidal interval is:12.5cm,15.8cm
Cross-power spectrum, coherence spectrum and number of mode
2008-6-2
Experiment Result of ECEI on HT-7 22
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
( ~ 1.7)eon
0k
0rk
poloidal correlation
0k
0rk
2008-6-2
Experiment Result of ECEI on HT-7 23
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
The Experiment Result of Zonal flow——toroidal
Toroidal correlationCross-power spectrum, coherence spectrum and number of mode.
As the increasing of density, the power spectrum, coherence and mode have characteristic of decrease.
Reasonable explain is that collision frequency of ion increasing, and result in the damp of zonal flow.
2008-6-2
Experiment Result of ECEI on HT-7 24
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
( ~ 1.7)eon
0k
0rk
toroidal correlation
0k
0rk
2008-6-2
Experiment Result of ECEI on HT-7 25
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Coexist of electron mode and ion mode at high density
TEXT-U has been utilized FIR&BES found the ion mode while measuring the fluctuation of density of high density.
At HT-7 we using ECEI measure the fluctuation of temperature and found the coexist of electron mode and ion mode in the high density of 4.5, and also found this phenomenon exist on low field side and high field side.
2008-6-2
Experiment Result of ECEI on HT-7 26
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
2D evolution of Te fluctuation ——low field side
Parameter: Ip=170kA ne=2.3 qa=3.3
2000 2500 3000-0.06-0.04-0.02
00.020.04
2660 2680 2700 2720 2740 2760 2780 2800 2820 2840-0.1
0
0.1
t (s) T
e/Te
1 23 4 56 7 8
1
r (cm)
Z (cm
)
8 10-10
-5
0
5
10
2
r (cm)8 10
-10
-5
0
5
10
3
r (cm)8 10
-10
-5
0
5
104
r (cm)8 10
-10
-5
0
5
10
5
r (cm)8 10
-10
-5
0
5
10
6
r (cm)8 10
-10
-5
0
5
107
r (cm)8 10
-10
-5
0
5
10
8
r (cm)
8 10-10
-5
0
5
10
-0.1
-0.05
0
0.05
0.1
Kink instability emerged and developing
Forms an ‘‘X point’’ in the poloidal plane leads to the reconnection
heat is accumulated outside the inversion radius and crashed the end
2008-6-2
Experiment Result of ECEI on HT-7 27
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
2D evolution of Te fluctuation ——high field side
Parameters: Ip=160kA ne=1.9x1019m-3
qa=3.2
Before the crash, it appear weak magnetic reconnection
At the end of broken up, their appeared evidence of heat starts to flow to the outside through a small opening.
140016001800200022002400-0.05
0
0.05
2000 2100 2200 2300 2400-0.1
0
0.1
t (s)
Te/
Te
1 2 34567 8
1
r (cm)
Z (cm
)
-8 -6-10
-5
0
5
10
2
r (cm)-8 -6
-10
-5
0
5
10
3
r (cm)-8 -6
-10
-5
0
5
104
r (cm)-8 -6
-10
-5
0
5
10
5
r (cm)-8 -6
-10
-5
0
5
10
6
r (cm)-8 -6
-10
-5
0
5
107
r (cm)-8 -6
-10
-5
0
5
10
8
r (cm)
-8 -6-10
-5
0
5
10
-0.08
-0.06
-0.04
-0.02
0
0.02
0.04
0.06
0.08
2008-6-2
Experiment Result of ECEI on HT-7 28
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Muti Magnetic Island-(Ⅰ)
2000 2500 3000-0.05
00.05
2650 2700 2750 2800 2850 2900 2950 3000 3050-0.1
0
0.1
t (s) T
e/Te
1 2 345 6 7 8
1
r (cm)
Z (cm
)
8 10-10
-5
0
5
10
2
r (cm)8 10
-10
-5
0
5
10
3
r (cm)8 10
-10
-5
0
5
104
r (cm)8 10
-10
-5
0
5
10
5
r (cm)8 10
-10
-5
0
5
10
6
r (cm)8 10
-10
-5
0
5
107
r (cm)8 10
-10
-5
0
5
10
8
r (cm)
8 10-10
-5
0
5
10
-0.15
-0.1
-0.05
0
0.05
0.1
0.15
The process evolvement of Dual Magnetic Island and crash up in the end.
Muti Magnetic Island in the surface of q=1 can only be trigged by mode of1/1,2/2,3/3,..
2008-6-2
Experiment Result of ECEI on HT-7 29
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Muti Magnetic Island-(Ⅱ)
The evidence of 1/1,2/2,3/3 mode exist in the surface of q=1
5kHz, 10kHz, 15.5kHz
0 5 10 15 20 25
-85-80-75-70-65
H(
)(dB
)
0 5 10 15 20 250
0.5
1
Cohere
nt
0 5 10 15 20 250123
mode n
um
/2 (kHz) #102843_5-9,5-7
0 5 10 15 20 25-100
-80
H()(
dB
)
0 5 10 15 20 250
0.5
1C
ohere
nt
0 5 10 15 20 250123
mode n
um
/2 (kHz) #102843_2-1,6-7
2 / /m r k m r
2008-6-2
Experiment Result of ECEI on HT-7 30
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Muti Magnetic Island-(Ⅲ) bicoherence spectrum Frequency discrimination:
0.78kHz have action of each other
the mode of 1/1,2/2,3/3
0 5 10 15 20 25 30 35 40 45 500
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
0.045
f (kHz)
b
2 (f)
#102843_4-6
2008-6-2
Experiment Result of ECEI on HT-7 31
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Summarization It have found the evidence of zonal flow from st
udying the fluctuation of electron temperature in the plasmas core
We found the coexist of electron modes and ion modes in the fluctuation of electron temperature.
The low field side and the high field side do exist the phenomenon of magnetic reconnection, so we can exclude the quasi-interchange model.
At the q=1 surface exist the modes of 1/1,2/2,3/3,..., and these modes caused the phenomenon of multi magnetic island.
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
CAS KEY LABORATORY OF BASIC PLASMA PHYSICS
Thank you!
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