Development*of*a*so.*X0ray*CCD* camera*system*in*LHD*and* - - PowerPoint PPT Presentation
P067 Development*of*a*so.*X0ray*CCD* camera*system*in*LHD*and* future*plan*to*reinstall*in*KSTAR** C.*Suzuki a ,*K.*Ida a ,*M.*Yoshinuma a ,*S.*Jang b ,*S.*Lee c ,*S.*Hong c ,*and*J.*Kim c * * a Na%onal)Ins%tute)for)Fusion)Science,)Toki,)Japan)
*
aNa%onal)Ins%tute)for)Fusion)Science,)Toki,)Japan) bKorea)Advanced)Ins%tute)of)Science)and)Technology,)Daejeon,)Korea))
)cNa%onal)Fusion)Research)Ins%tute,)Daejeon,)Korea)
! A*so.*X0ray*imaging*system*using*a*CCD*(Charge*Coupled*Device)*camera*and* beryllium*(Be)*filters*has*long*been*developed*in*the*Large*Helical*Device*(LHD)* at*the*NaLonal*InsLtute*for*Fusion*Science*(NIFS).** ! In*the*imaging*mode,*flux*surface*shape*can*be*reconstructed*from*the* measured*so.*X0ray*image*and*the*equilibrium*database,*from*which*magneLc* axis*posiLon*is*derived.** ! In*the*photon0counLng*mode,*electron*temperature*and*impurity*density*can* be*possibly*derived*from*the*slope*and*line*intensity*of*the*measured*spectra,* respecLvely.* ! Before*launching*deutrium*experiment*in*LHD,*we*are*planning*to*transfer*this* system*to*the*KSTAR*and*reinstall*it*in*an*appropriate*port*flange.** 1
! Heliotron*type*device*with*NbTi*superconducLng*coils*(<*3*T)* ! Major*radius*=*3.9*m,*Minor*radius*=*0.6*m,*Plasma*volume*=*30*m3* ! 5*beamlines*of*NBI*(3*negaLve*and*2*posiLve)*
13.5*m
! The*CCD*camera*was*installed*in*a*tangenLal*viewport*of*the*LHD*to*observe* tangenLal*so.*X0ray*images*of*the*plasmas.* 6T*port*
(tangenLal)*
Plasma* Viewing*Angle*
3.9*m*
3
Be*filter*disk*
0,*20,*50,*100,*200,* 400,*800,*1600*μm*
4
0.2 0.4 0.6 0.8 1 1 10
50)µm 70)µm 100)µm 150)µm 250)µm 450)µm 850)µm 1650)µm QE
Transmittance Photon)Energy)(keV)
99.8%)Be
Be*Filter*transmieance*&* CCD*quantum*efficiency*
CCD*chip*
(frame*transfer)*
Model* DO4350BV*(Andor*Technology)* Number*of*pixels* 1024*x*1024*pixels*(frame*transfer)* Pixel*size* 13*μm2*(back*illuminated)* Max.*A/D*rate* 1*MHz* Max.*frame*period* 0.25*s*@1MHz,*8x8*binning*
5
Supersonic*motor* for*the*filter*disk* CCD*camera* Supersonic*motor* for*the*pinhole* PneumaLc* shueer*
6
! Frame*transfer*CCD*can*measure*sequenLally*several*images*with*different*cutoff* energies*by*rotaLng*the*filter*disk*during*a*long*pulse*discharge.** ! An*image*for*a*specific*photon*energy*range*can*be*obtained*by*taking*the*difference* between*two*signals*measured*with*adjacent*filter*thicknesses.*
850μm–1650μm*
Energy@peak*:*4.8*keV*
C.#Suzuki,#K.#Ida,#T.#Kobuchi,#and#M.#Yoshinuma,#Rev.#Sci.#Instrum.#79#(2008)#10E929.#
50μm–70μm*
Energy@peak*:*1.9*keV*
So.*X0ray*image** Visible*image** AcquisiLon* Lming*
#84778* R* Z* 50*μm*filter* 2x2*binning*
7
repeLLve*pellet
! MagneLc*axis*shi.*(Shafranov*shi.)*can*be*derived*from*the*best*fit*of*the*pre0calculated* VMEC*equilibria*to*the*measured*so.*X0ray*profile*assuming*that*the*emissivity*profile* could*be*expressed*by*Fourier0Bessel*expansion.*
Measured Fieed
Be*filter:*450*µm* Pinhole:*0.05*mm best*fit*@*<β>=1.19%
Rax
v*=*3.85*m
C.#Suzuki,#K.#Ida,#R.#Sakamoto,#M.#Yoshinuma#and#the#LHD#Experiment#Group,#Nucl.#Fusion#50#(2010)#064013.#
8
! Hollow*so.*X0ray*emissivity*profiles*are*o.en*observed*in*high*ion*temperature* discharges*together*with*the*formaLon*of*carbon*impurity*hole.
2.25–2.5*s 2.0–2.25*s
Be*filter:*450*µm* Pinhole:*0.1*mm K.#Ida#et#al.,#Phys.#Plasmas#16*(2009)#056111.#
10000 20000 30000 40000 50000 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9
Counts R3(m) 2.0–2.253s 2.25–2.53s
9
50 100 150 500 1000 1500 2000 2500 3000 Number,of,pixels Count Am241 Fe55 Np,Lα 13.93keV Np,Lβ 17.75keV Mn,Kα 5.89,keV
Dark,charge
! SpaLal*and*energy*resoluLons*higher*than*those*of*PHA*can*be*obtained*by*operaLng* the*so.*X0ray*CCD*camera*in*the*photon*counLng*mode.* ! The*three*Kα*lines*from*Ltanium*(4.8*keV),*chromium*(5.7*keV),*and*iron*(6.6*keV)* appear*in*so.*X0ray*energy*spectra*measured*in*LHD.*
SensiLvity:*12*eV/count* Energy*resoluLon:*360*eV CalibraLon*by*X0ray*Source Energy*spectra*in*LHD
Ti Cr Fe
Y.#Liang#et#al.,#Rev.#Sci.#Instrum.#72#(2001)#717.##
10
B0port* Viewing*range
Seems*not*to*cover* the*edge*region
F0port* Viewing*range*
11
! Stacking*the*neutron*shield*blocks*to*protect*the*CCD*camera*near*the*port* flange.* ! Supplies*of*evacuaLon*system,*cooling*water,*pressurized*air,*etc.* ! InstallaLons*of*peripheral*devices*such*as*gate*valves,*shueer*and*filter*wheel* would*be*difficult*due*to*narrow*space*around*the*candidate*ports.** ! The*enLre*system*including*the*field*of*view*should*be*redesigned.*More* compact*system*(e.g.,*without*filter0wheel/driving*system)*may*be*favorable.* ! Cross0checking*the*space*availability*and*interference*issues*on*the*CAD* drawing*is*necessary.* 12
! The*diagnosLc*system*using*a*so.*X0ray*CCD*camera*and*Be*filters*had*been* uLlized*in*LHD*for*mulLpurpose*uses.* ! Two*operaLng*modes*of*the*camera*can*be*used*properly*for*the*purposes*we* need.*The*camera*had*been*mainly*used*in*the*imaging*mode*for*the*tasks*such* as*Shafranov*shi.*measurement,*energy*resolved*imaging*in*a*long*pulse* discharge,*and*hollow*emissivity*profile*in*a*discharge*with*impurity*hole.* ! The*photon0counLng*mode*is*also*available*for*the*measurements*of*so.*X0ray* energy*spectra*with*high*sensiLvity*and*energy*resoluLon*calibrated*using* standard*X0ray*source.* ! The*system*has*already*been*uninstalled*from*LHD,*and*we*will*transfer*this* system*to*the*KSTAR*and*reinstall*it*in*an*appropriate*port*flange.*The*enLre* system*including*the*field*of*view*should*be*redesigned.** 13