pellet charge exchange measurement in lhd & iter itpa 2006.9.4-8 tohoku univ. tetsuo ozaki,...
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Pellet Charge Exchange Measurement in LHD & ITER
ITPA 2006.9.4-8 Tohoku Univ.
Tetsuo Ozaki,P.Goncharov, E.Veschev1), N.Tamura, K.Sato, D.Kalinina and S.Sudo
National Institute for Fusion Science 1)Graduate Univ. for Advanced Studies
●Direct measurement of energetic particles in plasma （ proton, alpha etc. ）●Background neutral for charge exchange is required in passive measurement Difficult to obtain central information due to low back ground neutral around the plasma center. Double charge exchange is necessary to measure -particle Line integration
→Pellet Charge Exchange (PCX) by combination of TESPEL & CNPA PCX has been tried in TFTR for -particle measurement New results can be obtained even in non-DT plasma device →Diagnostic development
(1) Establishment of the PCX technique for proton (1/4 mass of )(2)Try helium ion measurement by using PCX(3) PCX in ITER
Pellet Charge Exchange Measurement
Diagnostic Principle of PCX
Injector
NPA
Ablation start Ablation end
. . .
dl = Dti ･ vpel
(Typically 100μs )
By measuring the charge exchange particle just behind the pellet trajectory, the time trace of the particle emission can be tran
slated to the spatial distribution.
vpel =500m/s→ 5cm
Corresponding to the ablation diameter
Experimental Apparatus
CNPA Viewing Cone
Pellet Injection Axis
Compact NPA ＣＮＰＡ（ Compact Neutral Particle Analyzer ）
Channel 40
Energy resolution Typically several ％
Energy range 0.8 ～ 168 keV
Time resolution 100μs
Experimental Setup
SD-NPA
CNPA&NDD
ＳＤ－ＮＰＡ ２５ ～４００ keV ２０４８ chPitch Ang. ４５～９０ deg6 cords
NBI 4
CNPATESPEL
NDD(Natual Diamond)
Typical CNPA
results in ICH plasma
CNPA 61213(100.0 ms)
0 50 100 150 200Energy (keV)
100
102
104
106
108
Counts
(c
/s*
keV
)
0.33 0.67 1.00 1.33 1.67 2.00 2.33 2.67 3.00 3.33 3.67 4.00
CNPA 61226(100.0 ms)
0 50 100 150 200Energy (keV)
100
102
104
106
108
Counts
(c
/s*
keV
)
0.33 0.67 1.00 1.33 1.67 2.00 2.33 2.67 3.00 3.33 3.67 4.00
ICH+NBI#1 （●○）、 ICH+NBI#1+#4 （■□） 、 ICH+NBI#4 （▲△）Closed marks （●■▲） mean the standard heating, open marks （○□△） mean the central heating of ICH. The difference of both cases is remarkable in the ICH+NBI#1. Particles from NBI#4 is also obviously observed.
2 4Time (s)
0
50
100
150
200E
ner
gy
(k
eV)
CNPA 61213 Counts max= 4.3e+007 (c/s*keV)
0.02
3
4
5
6
7
8
Co
un
ts
10
^y
(c/s
*k
eV)
2 4Time (s)
0
50
100
150
200
En
erg
y (
keV
)
CNPA 61226 Counts max= 4.5e+007 (c/s*keV)
0.02
3
4
5
6
7
8
Co
un
ts
10
^y
(c/s
*k
eV)NBI#1
ICH#5
NBI#4
NBI#1ICH#5
NBI#4
100
1000
104
105
106
107
108
0 50 100 150 200
2.67± 0.050(s) 3.00± 0.050(s) 3.67± 0.050(s) 2.67± 0.050(s) 3.00± 0.050(s) 3.67± 0.050(s)
Energy(keV)
標準標準標準
中心
Standard heating Central heating
3.686 3.688 3.6900
500
1000
1500
2000
2500
CNPA 61213 Counts
200
150
100
50
0
- 50
3.684 3.686 3.6880
500
1000
1500
2000
2500
CNPA 61226 Counts
200
150
100
50
0
- 50
Difference of the resonance positions in PCX
Rax=3.6,Bt=-1.25TRax=3.6,Bt=-1.375T
ICH 2nd harmonics-1.375T Standard heating-1.25T Central heating
In -1.375T, the flux increase at =0. ５ . However in -1.25T, no enhancement of the flax appears.
←Time trace of the charge exchange particle flux during TESPEL injection. Here the time means the pellet penetration depth. The pellet reaches =0.1. Vertical axis shows the particle energy.
3 3.5 4 4.5
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
3.686 3.688 3.6900
500
1000
1500
2000
2500
CNPA 61213 Counts
200
150
100
50
0
- 50
3.684 3.686 3.6880
500
1000
1500
2000
2500
CNPA 61226 Counts
200
150
100
50
0
- 50
Difference of the resonance positions
in PCX(cont.)
In the standard heating 、 the flux increases at =0.5. In the central heating, the flux increase can not be found because the the pellet trajectory is not cross the resonance surface. - 4.0 - 3.5
R (m)
0
50
100
150
200
Energ
y (k
eV
)
CNPA 61213 Counts max= 1.0e+008 (c/ s*keV)
3.6881(s)
0.02
4
6
8
10
Counts
10
y (
c/s*
keV
)
- 1.0 - 0.5 0.0 0.5
Rho
0
50
100
150
200
Energ
y (k
eV
)
CNPA 61213 Counts max= 1.0e+008 (c/ s*keV)
0.02
4
6
8
10
2
4
6
8
10
Counts
10
y (
c/s*
keV
)
ICH 2nd harmonicsStandard heating
ICH 2nd harmonicsCentral heating
-4.0 -3.5 -3.0R (m)
0
50
100
150
200
En
erg
y (
keV
)
CNPA 61226 Counts max= 1.9e+008 (c/s*keV) 3.6859(s)
0.02
4
6
8
10
Co
un
ts
10
^y
(c/s
*k
eV)
- 1.0 - 0.5 0.0 0.5
Rho
0
50
100
150
200
Energ
y (k
eV
)
CNPA 61226 Counts max= 1.9e+008 (c/ s*keV)
0.02
4
6
8
10
2
4
6
8
10
Counts
10
y (
c/s*
keV
)
Standard
Central
Difference of the ICH power
ICH 2nd harmonicsStandard heating
Flux increase is depended on the ICH power.
1.1MW 0.74MW
0.6MW 0.29MW
- 1.0 - 0.5 0.0 0.5
Rho
0
50
100
150
200
Energ
y (k
eV
)
CNPA 63600 Counts max= 1.9e+008 (c/ s*keV)
0.02
4
6
8
10
2
4
6
8
10
Counts
10
y (
c/s*
keV
)
- 1.0 - 0.5 0.0 0.5
Rho
0
50
100
150
200
Energ
y (k
eV
)
CNPA 63619 Counts max= 1.6e+008 (c/ s*keV)
0.02
4
6
8
10
2
4
6
8
10
Counts
10
y (
c/s*
keV
)
- 1.0 - 0.5 0.0 0.5
Rho
0
50
100
150
200
Energ
y (k
eV
)
CNPA 63620 Counts max= 2.0e+008 (c/ s*keV)
0.02
4
6
8
10
2
4
6
8
10
Counts
10
y (
c/s*
keV
)
- 1.0 - 0.8 - 0.6 - 0.4 - 0.2 - 0.0
Rho
0
50
100
150
200E
nerg
y (k
eV
)CNPA 63621 Counts max= 1.8e+008 (c/ s*keV)
0.02
4
6
8
10
2
4
6
8
10
Counts
10
y (
c/s*
keV
)
NBI#4
- 1.0 - 0.5 0.0 0.5
Rho
0
50
100
150
200
Energ
y (k
eV
)
CNPA 63837 Counts max= 1.5e+008 (c/ s*keV)
0.02
4
6
8
10
Counts
10
y (
c/s*
keV
)
Calculation by T.Watanabe NBI#4 Only
SD-NPA scan during ICH
long discharge(Vertical sight
lines)
0 200 400 600Time (s)
20
40
60
80
100
120
Energ
y (ke
V)
53754,99,5,120804,Ch4
0 200 400 600Time (s)
20
40
60
80
100
120
Energ
y (ke
V)
53754,99,5,120804,Ch1
Case1: Similar pitch angles
Flux increase at the resonance surface can be observed in SD-NPA vertical scan.
Vertical
Ene
rgy
Time （ =Position）
Vertical
helium detection in CNPA
Bvv qdt
dm E
vq
dt
dm
ezdd tvzz
)tan(
tan)( 3
xbyb
dde vv
yxxt
2
2 dz
d tm
qEz d
zzd t
m
qEv
)tan(
tan)( 2
xbyb
ccd vv
yxxt
)tan(
tan)( 2
xbyb
ccd vv
yxxt
L
bLyb r
xrxvv
0
Z
Detector
Spot on Detector
-12
-10
-8
-6
-4
-2
0
0 50 100 150 200
Z_H(cm)
Z_D(cm)
Z_He(cm)
Energy(keV)
Vd=Vd(H)/4.5
Beam Spot
Detector Size
-12
-10
-8
-6
-4
-2
0
0 50 100 150 200
V=V0/4
V=V0/4.5
V=V0/5
Energy(keV)
Beam Spot
Detector Size
Plate bias dependence
Energy loss in Cloud
0.1
1
10
100
1015 1016 1017 1018 1019
Helium Energy Loss
1(keV) 5(keV) 10(keV) 50(keV) 100(keV) 500(keV)1000(keV)5000(keV)
CloudDensity
0
60
11660
0
0
10960601
E
S.Z.E
E
E .nLi.
(by Sergeev)
He(ρ)
0
0.05
0.1
0.15
0.2
0.65 0.7 0.75 0.8 0.85 0.9 0.95 1 1.05
11(keV)_corr
12(keV)_corr
13(keV)_corr
Rho
Pellet velocity 440m/sAt plasma edge(ρ=1), the helium/hydrogen ratio of 0.085 is measure by visible spectrometer .We assume that the ratio is at the energy of 11keV （ minimum energy)
H
-5 106
0
5 106
1 107
1.5 107
2 107
2.337 2.3375 2.338 2.3385
11.6(keV) 12.4(keV) 13.2(keV) 14.0(keV) 15.8(keV)
time(s)
He
0
2 107
4 107
6 107
8 107
1 108
1.2 108
1.986 1.9865 1.987
11.5(keV) 12.4(keV) 13.2(keV) 14.4(keV) 15.6(keV)
time(s)
→Scattering of the hydrogen atom
He3 minority heating experiment
He-3 minority experiment had been tried in LHD 9th experimental campaign. He4 was used as the majority target gas. Small increase of the temperature could be obtained because the hydrogen still remained. We have plan to measure the He-3 spectrum/profile in the next experimental campaign.
ＩＣＨ
Ｔ i
Problem of PCX in ITER
TECPEL
Fisher,RSI
Large pellet with high velocity is required. plasma perturbationSmall charge exchange cross section of D,T
TECPEL (Tracer EnCapsulated PELlet) low perturbation good spatial resolution no special equipment
Li, Be D,T (fuel)
Fisher,RSI
ITER
ne=1x1020 (m-3)
Te=Ti=19.7(1-(r/a)2)+0.3 (keV)
Neutron and Gamma ray shielding
Shield requirement
TFTR: 2×1016 /s
Detector position 10m 8x108 /cm2s
Neutron flux in ITER: 104 of TFTR
6-inchs (polyethylene)+4-inchs (lead ）
neutron reduction 1/100 (TFTR)
→45cm(polyethylene)+30 cm(lead ）
Medley,RSI(TFTR)
ITER
Neutron, gamma
1013 /cm2s on the wall
ITER neutron spectrum
TFTR neutron shielding
Neutral Particle Analyzer for ITER
Scintillator material
(prefer thin film in order to reduce the radiation noise)
ZnS(Ag) low Ｘ -ray detection efficiency
long decay time (70 s)
→CsI(Tl) Deliquescence, but to be resolved by aluminum coating
for light protection
short decay time
E||B Detector saturation due to the strong n, -ray, high detection efficiency
TOF(Frascati) Time-of-flight for particle species selection, Low detection efficiency
GEMMA(Ioffe) Exchange to light, intermediate detection efficiency
Optical fiber Other improvement
Reference detector for noise reduction
Detector is far from the scintillator by using optical fiber
→ Shielding 、 reduce the magnetic effect for the photo-multiplier, reduce the radiation noise
GEMMA
Summary
●The preliminary demonstration of the alpha particle diagnostics using PCX and SD-NPA has been done.
● The high-energy particle flux enhancement around the resonance surface of ICH can be observed in the standard heating mode of ICH 2nd harmonics.
●The helium profile measurement has been tried by using PCX.
● PCX in ITER has been presented.
