charge exchange spectroscopic diagnostic for the tj-ii
DESCRIPTION
Charge Exchange Spectroscopic Diagnostic for the TJ-II. José Miguel Carmona Torres. Laboratorio Nacional de Fusion EURATOM-CIEMAT. Contents. Motivation Stellarator TJ-II Diagnostic Neutral Beam Injector Multichannel Diagnostic Beam Characterization Interaction and corrections - PowerPoint PPT PresentationTRANSCRIPT
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Charge Exchange Spectroscopic Diagnostic for the TJ-II
José Miguel Carmona Torres
Laboratorio Nacional de FusionEURATOM-CIEMAT
![Page 2: Charge Exchange Spectroscopic Diagnostic for the TJ-II](https://reader036.vdocument.in/reader036/viewer/2022062409/568147a6550346895db4e391/html5/thumbnails/2.jpg)
Contents
• Motivation
• Stellarator TJ-II
• Diagnostic Neutral Beam Injector
• Multichannel Diagnostic
• Beam Characterization
• Interaction and corrections
• Estimation of Counts
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Motivation
•DNBI has been installed on TJ-II
•CXRS local measurements of
IonTemperatures
Poloidal & ToroidalVelocities
Electric fieldsImpurity densities using experimental
data + simulation code
A lot of work to do…
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Contents
• Motivation
• Diagnostic Neutral Beam Injector
• Stellarator TJ-II
• Multichannel Diagnostic
• Beam Characterization
• Interaction and corrections
• Estimation of Counts
![Page 5: Charge Exchange Spectroscopic Diagnostic for the TJ-II](https://reader036.vdocument.in/reader036/viewer/2022062409/568147a6550346895db4e391/html5/thumbnails/5.jpg)
Stellarator TJ-II
•An Heliac Flexible device•Minor and mayor radii from 0.22 m to 1.5 m•B created by external coils (Bmax=1 T)•ECRH y NBI heating•Plasma cross section is bean-shaped
TJ-II Mag. flux surfaces for 2 diferent magnetic configurations. Magnetic Islands appers on diferent configurations as 58_83_61 .
Fully tridimensional plasma structure with easy access to portholes
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Contents
• Motivation
• Stellarator TJ-II
• Diagnostic Neutral Beam Injector
• Multichannel Diagnostic
• Beam Characterization
• Interaction and corrections
• Estimation of Counts
![Page 7: Charge Exchange Spectroscopic Diagnostic for the TJ-II](https://reader036.vdocument.in/reader036/viewer/2022062409/568147a6550346895db4e391/html5/thumbnails/7.jpg)
Diagnostic Neutral Beam Injector
DNBISECTOR
A7
TOPPORTHOLE
NBI_1 NBI_2
Scheme of DNBI
Picture of DNBI installed in the TJ-II
Dnbi Parameters-Focal length 170 cm-Pulse length 5 ms -Beam Energy ~30 KeV-1/e divergence <0.7 º-1/e radius at focus ~21 mm-Extracted ion current 4 A/cm2
-Beam Components (H,H2,H3) ~90%, ~8%, 2%
DNBI sector A7, mounted on a support structureRev. Sci. Instrum. 75, 3499 (2004)
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Contents
• Motivation
• Stellarator TJ-II
• Diagnostic Neutral Beam Injector
• Multichannel Diagnostic
• Beam Characterization
• Interaction and corrections
• Estimation of Counts
![Page 9: Charge Exchange Spectroscopic Diagnostic for the TJ-II](https://reader036.vdocument.in/reader036/viewer/2022062409/568147a6550346895db4e391/html5/thumbnails/9.jpg)
Multichannel Diagnostic
Canon 85 mmF/1.2 l USM
12 fiber arrayFiberguide Industries
diameter 600m
Holospec Spectrographf/1.8 high resolution and high dispertion grating
CCD Pixis Princeton Instrum. back-illuminated 1024 x 1024 Pixels (13 m)
J.M. Carmona et al. HTTP Conference 2006, Virginia, USA
*
* Ilustration from Alcator
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Multichannel Diagnostic
J.M. Carmona et al. Rev. Sci. Instrum. 77, (2006) In press
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Contents
• Motivation
• Stellarator TJ-II
• Diagnostic Neutral Beam Injector
• Multichannel Diagnostic
• Beam Characterization
• Interaction and corrections
• Estimation of Counts
![Page 12: Charge Exchange Spectroscopic Diagnostic for the TJ-II](https://reader036.vdocument.in/reader036/viewer/2022062409/568147a6550346895db4e391/html5/thumbnails/12.jpg)
Beam CharacterizationHypothesis:• Homogeneos source• Elemental beams emitted from source dS• of neutrals Termal Distrib.Multiple sum of coaxial Gaussians
V
2
2
exp)(),(zr
zgrzzj f
b
b
t
b
TE
v
v
2
2
• Convolution between Gaussians and Q(rz)=Q(r1-z/zf)
20,exp0,),( rzj
Izjrzj
j(z,0) I
a2
z*2
z21 exp
a2
z*2
Neutral beam profile in vacuum:
2
*
2
2
*
2 0,expexp1),( 2
2
rzjIz
azz
aI
rzj
P. Bosshard Thesis, TCV
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Contents
• Motivation
• Stellarator TJ-II
• Diagnostic Neutral Beam Injector
• Multichannel Diagnostic
• Beam Characterization
• Interaction and corrections
• Estimation of Counts
![Page 14: Charge Exchange Spectroscopic Diagnostic for the TJ-II](https://reader036.vdocument.in/reader036/viewer/2022062409/568147a6550346895db4e391/html5/thumbnails/14.jpg)
Interaction and corrections
totimpimp
totpp
b
eee nn
v
vn
•Beam attenuation by means of collisions
z
z
dzzIzIdzI
dI
0
exp)(/)( 0 attenuation coefficient
Proton and Imp.densities?
eeff
impeeff
p nZZ
Znn
Z
ZZn
)1(
1
1
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Interaction and corrections
•Some corrections on are needed ve
ADAS databaseVneutrals<<Velectrons
f (Te)
•Vneutrals=30 KeV Vneutrals106 m/s Velectrons107 m/s
e
be
b
e
e
eber T
Ev
MT
mE
vvv 132
b
e
M
mwith
3
2
effreff TvE 2/32/1 2
2/1 ebeeff TETT
J.M. Carmona et al. EPS Conference. Tarragona 2005
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Contents
• Motivation
• Stellarator TJ-II
• Diagnostic Neutral Beam Injector
• Multichannel Diagnostic
• Beam Characterization
• Interaction and corrections
• Estimation of Counts
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Estimation of Counts
•Photons? Charge-Exchange
h (CVI 87)
•Number of photons
PCX
1
4Aij(8 7)
Aijv i N idl
i
N imp t sist
Branching RatioRate coefficients for 30, 15, 10 KeV Optical window, lens, fibers, coupling,
spectrograph and CCD total efficiency
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Some results
An ‘artistic view’ of the simulation code, showing attenuated (red) vs non-attenuated beam (green)
First measurements are expected to be obtained in the next campaign