1
平成 24 年度 ダイバータおよびPWI合同研究会 �2012.7.22-23!

デタッチメント領域におけるプラズマ診断法�
~ダイバータ模擬装置MAP-II における開発事例~!
Shinichiro KADO (門 信一郎), School of Engineering, The University of Tokyo!
Contributors: 岡本敦
U-Tokyo (PD) --> Tohoku-U ( ~ 2005 LTS)!
F. Scotti
U-Tokyo -> PPPL, US (Ph-D) ( ~ 2007 LTS)!
!
鈴木健二
U-Tokyo Master graduate.
( ~ 2009 Stark) !

1 ) Introduction:!
Detached recombining plasma!
He I spectroscopy!

He discharge (59 V, 30 A) , 80-180 mTorr !
LTS observation @Source Chamber!
(CF253 port)!

2) Development of the LTS!
for recombining plasmas!
3) Development of the Doppler- !
Stark Spectroscopy (He I).!

Laser pass !

4) Results (LTS and OES)!
20060324EIR̲Thomson.MOV�5

MAP - II Divertor Simulator �
S. Kado et al., J. Plasma Fusion Res. 81, 810 (2005).

- 1st/source chamber: high ne	

Probe measurements are limited in low
density operations. ---> LTS. 	

- 2nd/target chamber: good controllability	

equipped with many diagnostics.	

- Drift tube with two orifices:	

MAP-II	

target chm	

source chm	arc source	

- arc source 	Cathode: LaB6 disk	

(φ 30 mm with a hole φ 5mm)	

Anode: Pipe	

Discharge ~ 60-100 V 	

30-45 A, 	Ballast resister 1 Ω	

B- field 	 ~ 20 mT	

Working gases: H2, He Ar 	

Puffing gases: He, H2 CxHy	

Pressure ~ 1~30 mTorr 	

6

MAP-II (Material And Plasma) Divertor Simulator !
Arc discharge: !
70-100V, 30-45A!
B = 0.02T !

TMP for Differential Pumping:!
on--> attached condition!
off--> detached condition!

LTS and OES systems on MAP-II (source chamber)�

7

target chm	

source chm	arc source	- A second harmonic Nd:YAG Laser	(≤ 400-500 mJ / pulse @532 nm, 7 ns, 10 Hz)	- ICCD is used (YAG-TVTS). Doppler profiles can beobtained. 	

- Viewing optics are also used for the optical emission
spectroscopy (OES) for the comparison with LTS. 	

For low-n	

Low resolution
spectrometer	

(Δλ ~ 0.5 nm,
190-850 nm)	Linear CCD	(2048 pix,12bits)	

For high-n	

High resolution
scanning
monochromator	

(1m, 2400gr/mm
Δλ ~ 0.03 nm, )	

PMT	

8

Volumetric Recombination Processes (H2, He .....)!
EIR

H 2 -MA R

10 -9 cm 3 /sn e = 10 1 4 cm -3

I. Electron-Ion Recombination (EIR) !
3BR�

M+ + e + e -> M* + e�Rad.R�

M+ + eTe < 1 eV!

-> M* + hv�
Rydberg spectra (high-n)!

10 -10II. Molecular Assisted Recombination (MAR), H2, CxHy,! 10 -11(1)!DA� H2(v) + e ->�H2- -> H- + H�
MN�[Fulcher]�

[Photo-detachment]�

H- + H+ ->H + H*�

K MAR

K EI R

10 -12

K ion (H2)

K ion (He)(2)! IC� H2(v) + H+ ->�H2+ + H�DR�Te < 2-3eV!

H2+ + e ->H + H*�

10 -1301

2!

0.06eV!

2

3

complex excitation processes!
Te[eV](low-n modified)!
Krasheninnikov et al. Phys.Plasmas(1997)1638�

Since the processes strongly depend on Te,!
requirement of the diagnostics yiels:!
Ionizing plasma (ex. glow discharge) Te ≥ 2 eV !
for H2-MAR
Min. Te ≤ 2 eV!
for EIR
Min. Te ≤ 0.1 eV!

0.1!

9

A problem in the measurement of Recombining Plasmas 	Kado et al., J. Nucl. Matt. (2003))	

Probe I-V
characteristics!

Ie	

Ii	

Low Recycle	

High Recycle	

Anomalous Ie decrease, (Only Ii believable):!
・Overestimation of Te!
・ne becomes immeasurable（owing to Te ） !
・also has an effect on negative ion diagnostics!

Detached	

Ii	

Ie	

D2 -EIR(JET)	

Monk et al, J. Nucl. Mater. 241-243 (1997) 3960

(1) probe contaminations �(2) potential burst�(3) Impedance of the plasma �(4) Other unknown effects �He I line emission spectroscopy	

101) High-n Boltzmann plot method.!
2) Collisional Radiative model!
transitions to n = 2!
（many useful lines，optically thin） !
→ suitable for line ratio measurement．!
Upper-states：mainly n = 3, 4!
[*] Y.Iida, S.Kado, et al., RSI 81, 10E511 2010.

VIS	

2058	

Meta-stable	

NIR 	

VUV	

Singlet	
Ground	- Radiation trapping included for 1P
states（resonant to 1S）!
Otsuka-model -- @center !
Iida-model (2010) -- @arbitral!
----> Imaging spectrometry!
1083	

Meta-stable	

Triplet	3) near-infrared spectroscopy for 21S- 21P (2058.130 nm) !
--- on-going!

Radiation trapping for resonant 11S-n1P(n=2~7): A -> ΛA!
optical escape factor Λ, absorbtion length L [Otsuka(1979)]!
plasma radius (2.5 cm) < L < chamber radius (25 cm)!
2.5 cm yields good fit with data with Tgas=400K (~Trot(H2))@center	

11

Rydberg spectra: Partial-LTE in the Helium EIR plasmas!
⎛ I λ ⎞⎛ n( p) ⎞ΔEp pqlog⎜⎜+K⎟⎟ ∝ log⎜⎜⎟⎟ = −AggkT⎝ pq p ⎠⎝ p ⎠e

MAP-II He EIR Plasma

if the plot lies on the straight line above
n=p, it is in p-LTE with free electrons	

LangmuirProbe

Te [eV]

4

Ionizing Plasma

NAGDIS-II He EIR Plasma
ProbeAnomaly32100Immeasurable
Missing Link
(no emission)?

Reliable ?
5

10partial - LTE
Boltzmann Plot

Spectroscopy
15

20

EIR

5

25

Pressure [mTorr][Ohno et al. Contrib.Plasma Phys. (2001)473]!

I λ / Ag [arb.unit]

€

2
5

10 8

1

n=9

6
4
2
4

10 8

1

2 P-n S
1
1
2 S-n P
1
1
2 P-n D
3
3
2 P-n S3
3
2 S-n P3
3
2 P-n D

Te ~ 0.06 eV!

6

24.0

24.2
24.4
Excitation Energy [eV]24.6

- Spectroscopic measurement always reflects
the brightest point. Q: Really that low? . !
-Transition layer cannot be measured either
by a probe (due to the anomaly) or by passive
spectroscopy (due to the absence ofemissions). !
- Laser Thomson Scattering（LTS）is expected
to fill the gap between these measurements.!

12�

How to evaluate the lines based on the CR model �
Rate equation:	

efflux	

influx	⎧⎪⎫⎪dn ( p)= −⎨ ∑ C p →q n e + S p n e + ∑ A p →q ⎬ n (q) + ∑{Cq →p n e + Aq →p }n (q) + {α p n e + β p }n i n e⎪⎩ q≠ p
⎪⎭
dt
q< p
q≠ p
3BR	

 Rad.Rec	ex.&deex.	

 ion.	

 decay	33(a)n(587; 3 D)/n(447; 4 D)

14

€

4
2
12

10

7

4
5

5

6
7
8
8
9
11 12 1013
13
15 16 1417
8 10 12 14

4
3

4
2
11

10

n[He]=12 mTorr, Tgas=400 K, L=25mm

6

5
3 4 2

6

7

Model: Fujimoto(1979) Goto(2003)	

Radiation trapping implemented : Iida (2006) 	

10

1

-3

Recombining &	 Ionizing plasma	

2
13

1

4

2

n( p) = R0 ( p)n e n z + R1 ( p)n e n11 S

ne[cm ]

€

10

5

10
Te[eV]

15

Sensitive parameter ranges for the line-ratio technique:!
(1) Contours parallel to Te (or ne) - axis ---- ne (or Te) measurement.!
(2) No parallel contours but other pair with other tendency (cross point)!
!Simultaneous equations -- ne-Te!
(3) No clear dependence -- need to check convergence properties of the least squire fitof the population ratio ri = n(i)/n(ref) to the evaluation function as follows:!
2⎛ riCR (Te ,n e ) − riEXP ⎞ 2
⎛ riCR (Te ,n e ) − riEXP ⎞ 2
riCR (Te ,n e ) − riEXP )(f (Te ,n e ) = ∑⎜, ∑⎜⎟ , ∑⎟ ,etc.....
CR
CR
EXP
r
r
Δr
⎠ i
⎠
i
i
i
i ⎝
i ⎝

13

Lines used for He I CR model ( n= 3, 4)�
- Low-dispersion simple spectrometer (CCD of 2048 pixs, 12bits) wasused for the low-n (3 and 4) spectra.!
- High resolution scanning monochomator (PMT) for Rydberg spectra. !

8

photon flux (10 ) [arb. unit]

Spectra obtained in the single acquisition!
2.5 116 mTorr
2.0

1.0

3

3

2s-np(S)4

1.5

2p-ns(S)42s-np(T)

2p-nd(S)2p-ns(T)3

2p-nd(T)

4

0.5
0.0
300

400

500
600
wavelength [nm]Merits (low-n states):!
- Brighter line emissions!
- Good line separation.!
- Fast measurements!(< minutes)!
Demerits:!
- Accuracy not examined. !

700

Rydberg series: dark, less separated (requires high resolution monochromator), !
--> requires very long scanning time. !
- Supposed to be accurate in terms of Te determination (many sensitive lines). !

CR-model (high-n) vs Boltzmann Plot method!
10

N(n) / N(n=9)

LTE( 0.06 eV)

He I: 2p-nd(Triplet)⎛ I λ ⎞ΔElog⎜⎜ m mn ⎟⎟ = −
+K
A
g
kT
e
⎝ mn m ⎠

92

CR-model best fit (0.05 eV)	CR(n=18)=LTE(n=18)

1
6
5
4

BP: LTE(n≥9) -> ~ 0.06 eV	CR model vs LTE (Te= 0.06 eV)

6
5
4
3

12

CR modeln( p) = r0 ( p,Te )n e n z(0.06 eV, 1.7e+12 cm3, L=2.5cm)

3= r0 ( p,Te )n e2

2

0.1
24.30

deduced Te [eV]

0.20

24.35

24.40
24.45
Energy [eV]

24.50

24.55

LTE for n >12 (It depends on density.)!
Te (p-LTE) > Te (CR) slightly(~0.01 eV).!

Boltzmann plot vs CR model
Boltzmann plot result
from CR model distribution(0.05 eV)

0.15

€

fitting (n = 9 - 15)

1)
2)

0.10

3)
0.05
0.00

14

CR best-fit n=[p, 15][#calculation ]
4

6

8

10

Te=0.05 eV
12

14lower principal quntum number for fitting

16

calculate 0.05 eV distribution (CR)	

perform fitting to the distribution
based on LTE (for n =[p , 15])	

compare with each other	

Results of Boltzmann plot converges tothe best-fit value (0.05 eV) of CR model	

as lowest n increases.	

He I

3D-system

15�

spatial distribution �[日本物理学会20aTJ-9 2010.3, 鈴木 M論 ]�

n=3~9 3D terms, spatial distribution: n-dependence become more obvious for higher pressure�

中圧力：8.0 mTorr�

低圧力：4.0 mTorr�
lower�

higher �

n=3の幅で規格化した各準位の発光幅�

高圧力：15.5 mTorr�

再結合プラズマ：	

上下非対称	

本研究では（プラズマ上部が顕著）	

空間構造を調べる必要性�

ここでは，3D系列のみを示したが，共鳴線である1P系列以外の系列は同傾向をしめす．�

16

Temperatures of ion, electron and neutral (ionizing plasma)�
Discharge Electric Field! Glow-- ~ 400-600V!
Arc -- ~ 10-100V!
1 eV = 11604 K!
RF!
thermalize!
electron!
rigid-!
body!

coulomb col.!

ion!
Ti ~ 0.1Te ~ 4000K !

Te~4 eV!

surface recombination!

neutral!

wall!

Tn ~ 300 - 800K ~ Twall !
ne ~ni ~ 1011-13 cm-3!
nn ~ 1015 cm-3!

In the usual laboratory plasmas,
thermal equilibrium can beachieved ONLY in each species,
and NOT between them. 	

How about the recombining plasma ? !

Temperatures of ion, electron and neutral (recomb. plasma)�

17

Discharge Electric Field! Glow-- ~ 400-600V!
Arc -- ~ 10-100V!
1 eV = 11604 K!
RF!
thermalize!
electron!
rigid-!
body!

coulomb col.!

Te~ 600 K!

neutral!

ion!
Ti ~ ? !

wall!

Tn ~ 300 - 800K ~ Twall !
ne ~ni ~ 1011-13 cm-3!
nn ~ 1015 cm-3!

A hypothesis (by Kado)!
- No energy input.!
- Possibility that electrons, ions andneutrals are undistinguishable. !
-Thermal equilibrium achieved ？ !

Motivation	20

Difficulty and the Solution to Te Diagnostics for LTS!
Main sources of difficulties in the application to low Te , ne plasmas:•Small fraction of scattered photons•High level of stray light• Bright optics (low F-number)•Stray light rejection techniques•Data accumulation- Filter polychromator ( ≥ 1nm band width) or
notch filter (~ 17 nm stop band) cannot be used.
Filters-Grating monochromator + stray light rejection-High wavelength resolution, leading to a possibility ofvery low Te measurements.
- Lower limit of Te is determined by the size of the stop
band: Rayleigh Block (RB), in stead of the notch
filter
The stop-band can be reduced by reducing RB
dimension and/or increasing dispersion

Stray light

10 eV

Rayleigh
Block

0.5 eV

1-2 nm/mm for Te< 40 eV !

21experiments: MAP-II divertor simulator�
He Recombining Plasma: (Electron-Ion Recombination: EIR) 	
[#26100, 10.48, 83.3 mTor, 20081121/ IMG0057.JPG ]	

pure He (~ 60 V, 30 A) , 80-200 mTorr !
pressure ＝ LTS position@Source Chamber!

0	

1	

2	
 3	

Ionizing	
Recombining
upstream	front	
ionizing	
Recombining	
downstre
Brightest point	am	
Te > 2 eV! ~ 1eV! ~ 0.2 eV! < 0.1 eV!

Laser pass !
20081121̲Thomson̲MVI̲0064̲trim.mp4	

Stages of the development of Double Monochromator (DM)
Ionizing! H2-MAR!
Transition!
EIR!
4 eV ! 3! 2! 1!
Interference filter !

0.5!

0.3!

22

0.1! 0.08! 0.06! 0.04!

Safety margin(fitting mask)!

Ideal limit (by RB)!

System-0 : Conventional DM (= Homo-Tandem type)!
0.2 - 0.3 ≤ Te ≤ 40 eV ( 2004- 2005 ) !
A. Okamoto, S. Kado, et al.,Rev.Sci.Instrum. 76(2005). !

System-I !
0.07 - 0.13 ≤ Te ≤ 40 eV ( 2006 ) !

Rayleigh block:!
Ø~0.3mm!

DM: focal length!
135 + 135 mm!
(F/2.8)!

Ø~0.2mm!

F. Scotti, S. Kado, et al.,Plasma Fusion Res. 1 (2006) 054 .!

System-II : Development of Hetero-Tandem DM!
0.03 - 0.048 ≤ Te ≤ 40 eV
F. Scotti,and S. Kado, J. Nucl. Matter. (2009).

(2007 - )!

200 + 100 mm!
(F/2)!

23

Example of the LTS spectra (H2-MAR, System 0)�
hand-made double monochromater!

intensity [103 arb. unit] intensity [103 arb. unit]

probe beam -- Nd:YAG laser (532 nm, 300-400 mJ/pulse, dt =7 nm, 10 Hz)!

block-0.35 mm (f=135 mm, 1800 lines/mm) ---> Te > 0.3 eV!

43

shot# t10tc
Te= 5.8 +/- 0.5 eV
ne=(7.5 +/- 0.3) x1012 cm-3
(He+H2) : 0.69 Pa

2(a)masked data

fitting(gaussian)fitting

shot# t13tc
Te=2.0 +/- 0.1 eV
ne=(7.7 +/- 0.3) x1012 cm-3
(He+H2): 5.1 Pa

(b)

1
0
3
2
1

2005.02.18

0
524

526

528

530

532

534

536

wavelength [nm]The Thomson signal is obtained after the subtraction ofstray light.
The central notch filtered region is avoided in theGaussian fitting by means of a mask function.

Upper：5.8 eV !
Lower： 2.0 eV!

Hetero-Tandem Double Monochromator (hand-made)�

24

Reciprocal linear dispersion

f=135	

f=135	

 F/2.8	

Port for triple 	

monochromator	

€

F/2	

f=200	

f=100	1
1
1=+
⎛ dλ ⎞⎛ dλ ⎞⎛ dλ ⎞
⎜ ⎟
⎜ ⎟
⎜ ⎟
⎝ dx ⎠ 2X ⎝ dx ⎠1st ⎝ dx ⎠ 2ndRayleigh block: Ø~0.2mm
Groove frequency 1800 gr/mm

1st Rec.Lin.Disp.(nm/mm)
Sys. I: 3.14
Te=0.07eV
Sys. II: 2.03
Te=0.03eV
2nd Rec.Lin.Disp.(nm/mm)
Sys. I: 3.14
Sys. II: 4.05
2X Rec.Lin.Disp.(nm/mm)
Sys. I: 1.57
comparable
Sys. II: 1.36

25

Upgrade of the spectrometer: Sys. 0, I  Sys. II �
Intensity [Arb. Units]5
Te=0.31±0.03 eV
13-3
ne=1.4±0.2x10 cm

4
3
2
1
0
-1
529

530

5

Intensity [Arb. Units]

System I!

4
3

531
532
533
Wavelength (nm)Te=0.051 eV
12-3
ne=3.72•10 cm

534

535

System II!

2
1
0
-1
529

530

531
532
533
Wavelength (nm)

534

535

The practical lower limit was reduced
from 0.13 to 0.048 eV !

LTS vs Spectroscopy (high -n) at EIR front: Sys. II�
Precise comparison of LTS and OES(BP&CR) for the EIR front.

2�

0.1�

26

0.06eV�

Schematic line- integrated	

brightness	

He, 64V, 30A!
Electron Temperature (eV)

0.13
0.12
0.11

LTS0.9 eV@ 13.8 Pa

0.10
0.09

Te LTS1
1
BP: 2 P-n D (n=9-16)
3
3
BP: 2 P-n D (n=9-16)
CR (n=9-16)

no emission

0.08
0.07
0.06 #25920-25925
0.05
14
16
18
20
22
24
Neutral Pressure (Pa)26

Te (LTS) monotonicallydecreased until 0.065 eV,
which agrees well with thoseobtained from the Boltzmann
plot(BP) method (0.068 eV)
for the Rydberg series andfrom CR model (high-n).

Deviation around the brightest
point is attributable to theintegration effect:
28
LTS -- Te at the tip
Spec. --Te in the bright cone.

Te(high-n, BP and CR) ~0.06 eV ��-- confirmed by LTS[ ] Scotti and Kado, J. Nucl. Matter. 390-391, 303-306 (2009) �27

LTS spectra�
13

5x10

Electron Temperature (eV)Electron Density (cm-3)

13.81 Pa
2 mask 1

4

ne LTS

1
0

3
2

-1
528

1

5

0
1

4

8
6

3

4

1
0

8
6

0.01

534

536

532

534

536

532

534

536

18.8 Pa
mask3

-1
528

0.1

2

532

2

2

4

530

3

Te LTS
1
1
Te_Boltzmann_2 P-n D (n=9-16)
3
3
Te_Boltzmann_2 P-n D (n=9-16)
Te_CRmodel_Rydberg (n=9-16)

14 16 18 20 22 24 26 28
Neutral Pressure (Pa)530

21.86 Pa
mask

2
1
0
-1
528

530

LTS and Stark Spec. on MAP - II Divertor Simulator �
Arc source with B- fiel ~ 20 mT	

Cathode disk (LaB6 φ 30 mm), Anode: Pipe 	

Discharge ~ 60-100 V
30-45 A,	- 1st/source chamber: high ne	

Probe measurements are limited in low
density operations. ---> LTS. 	

- 2nd/target chamber: good controllability	

equipped with many diagnostics	

expander	

optics�28

Difficulty and the Solution to T(p) Diagnostics for OES�

n=8	
n=3	

29�

He I line broadening：!
i) instrumental function: with aberration!
ii) Doppler (temperature): WG Gaussian!
iii) Stark （density）: WL Lorentzian!
(ne > 1013 cm-3，!
principal quantum number n ≥ 6)!

ex. 93D (6 fine structures)	
1m 2400 g/mm， x6 	
dispersion: 0.5~1 pm/pixel	
Inst̲FWHM 7.5~12.5 pm	
Practically, however, it is difficult todetermine WL and WG at the same time!
(freedoms for both could compensatedfor each other)!
Therefore, we have proposed measuring line profile of several spectra, in which
the contribution balance of Gaussian and Lorentzian is different: !
low-n More Doppler ---- Atomic temperature!
high-n Doppler and Stark ---- Temperature and electron density !
Question: Temperature of which state ? !

Origin of the Population in Recombining Plasmas�
⎧⎪
⎫⎪
dn ( p)= − ⎨ ∑ C pq n e + S p n e + ∑ ΛA pq ⎬n ( p) + ∑ Cqp n e + ΛAqp n (q) + α p n e + βp n i n e⎪⎩ q ≠ p
⎪⎭
dt
q< p
q≠p

{

ex.&deex.	
ion.	
decay	€

excitation!

recombination!

}

{

}

30

-efflux (Γef ) + influx: (Γin)	

3BR	
Rad.Rec	
Influx from the Ground/Influx from Ion	Γin(11S->p) / Γin(ion ->p)	
Ion Temp.!
Past research:	
Ionizing Plasma：	
Ion collision contributes tothe high-n D series	
1S 1P 1D 3S 3P 3D	

Atomic Temp.	
Influx via 1P states,	Γin(1P->p) �．[K. Suzuki, master thesis, U-Tokyo(2010)]	

The present research	
Recombining Plasma：	
1P：Gas Temperature	
1S, 1D：mixture	
high-n 3D：Ion temperature	
30�Proposal of the Selection of Spectral Line Shapes�
Empirical equation of the Voigt Profile (convolution of Gaussian andLorentzian) as a function of wavelength normalized to its peak
centered at has been proposed in ref.[*] as �
2 ⎞
2 ⎞ −1
⎛
⎛
⎛
⎞
⎛
⎞
⎛
⎞
I( λ)
W
λ − λ0 ⎟ W L ⎜λ − λ0 ⎟= ⎜1 − L ⎟ exp⎜⎜ −2.772⎜
1+4⎟ ⎟ +⎜⎟I0
⎝ W V ⎠ ⎝⎝ W V ⎠ ⎠ W V ⎜⎝⎝ W V ⎠ ⎟⎠−1
⎛ W L ⎞ W L ⎛⎜ ⎛⎛ λ − λ0 ⎞ 2.25 ⎞ ⎛⎛ λ − λ0 ⎞ 2.25 ⎞ ⎞⎟
+0.0016⎜1 −exp⎜⎜ −0.4⎜⎟⎟ ⎟⎟ − ⎜⎜1+ 0.1⎜⎟ ⎟⎟
⎜
W
W
W
W
⎝
⎝
⎝
V ⎠
V
V ⎠
V ⎠
⎠ ⎝
⎠ ⎟⎠
⎝ ⎝

€

WL
W L2
WV =
+
+ W G ≡ W L [+]W G
2
4

WV(31P) = WG(31P) = WG(T(He0)), ----> Atomic Temperature!
WV(7€ 1P)= WG(T(31P)) [+]WL(71P). -----> Electron Density!
WV(73D) = WG(73D) [+]WL(ne(71P)), -----> Ion temperature!
[*] E.E. Whiting, J. Quant. Spec. Rad. Trans. 8 (1968) 1379–1384�

31

Results : Use of Line profiles of Three Transitions �

32

WV(31P) = WG(31P) = WG(T(He0)), ----> Atomic Temperature!
WV(71P)= WG(T(31P)) [+]WL(71P). -----> Electron Density!
WV(73D) = WG(73D) [+]WL(ne(71P)), -----> Ion temperature!

Fitting was performed in theregion free from the coma
aberration (blue wing in UV
region)�
[*] S. Kado,et al., J. Nucl. Matter. 415, S1174–S1177 (2011). �Comparison between LTS and Doppler-Stark : (preliminary)�
ne： LTS vs Stark(71P)	

T： LTS vs Doppler (31P, 73D)	

31P	

T(31P)=T(71P)=T(11S) : assumed!
ne(Thomson) > ne(Stark:71P ) !
1/2 difference -> integration effect!
Values from Stark are plausible.!
Using ne(71P) to determine T(73D) from
Voigt profile can be reasonable.!

73D	

ionizing!
T (11S) < T(73D) < Ti!

Recombining!
Ti = T(73D)!

Recombining regime，!
31P(atom)，73D(ion) and electron areachieving thermal equilibrium among
them．!

33

34

Doppler-Stark Spectroscopy for He I line broadening 	
WV(31P) = WG(31P) = WG(T(He0)),-----> Atomic Temperature!
WV(71P)= WG(T(31P)) [+]WL(71P).
-----> Electron Density!

Meta-stable	

NIR 	

VUV	

Singlet	
Ground	!

WV(73D) = WG(73D) [+]WL(ne(71P)), !
-----> Ion temperature!
(in recombining plasmas)!

VIS	

2058	

!

1083	

Meta-stable	

Triplet	[*] S. Kado, K. Suzuki, Y. Iida, A. Muraki, "Doppler
and Stark broadenings of spectral lines of highly
excited helium atoms for measurement of detachedrecombining plasmas in MAP-II divertor simulator" J.
Nucl. Matter. 415, S1174–S1177 (2011). �35Conclusions �
LTS for the study of low-temperaturedetached recombining plasmas. 	

Discharge Electric Field!
thermalize!

electron!
rigid-!
body!

coulomb col.!

ion!

Te~ 600 K!

neutral!

wall!

Tn ~ 300 - 800K ~ Twall !
Doppler-Stark line broadening for3 lines, (31P), (71P), (73D) enabled
the determination of Atomic
Temperature, Electron Density,
Ion temperature in recombining
plasma.!

Conventional Homo-tandem double
monochromator(system 0 to system I )yielded 0.13 eV. (transition region)	

Major upgrade to the system II has
achieved the requirement of 0.06 eV, for
the EIR plasmas.	

It was confirmed that the Te from theRydberg series spectra of He I, about 0.050.06 eV, is actually the Boltzmanntemperature. 	

Thus it was verified experimentally thatthe ion, electron and neutral atoms
tend to achieve thermal equilibrium
among them in recombining plasmas. !

36Thank you !�