Study of transport simulation on RF heated and current driven EAST plasma Siye Ding Under...
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Transcript of Study of transport simulation on RF heated and current driven EAST plasma Siye Ding Under...
Study of transport simulation on RF heated and current driven EAST
plasmaSiye Ding
Under instruction of Prof. Baonian Wan12/09/2009
Outline
• TRANSP & pTRANSP program
• Feature of NSTX plasma --- Transport analysis work at PPPL
• Preliminary results of EAST simulation
• Summary
TRANSP
• Category: Experimental Data Analysis• TRANSP descended from BALDUR in the 1970s • The complete system includes:
– A million lines of FORTRAN code– Over 100 executable programs– Over 100 subroutines– More than 100 Man-Years invested in developing code
• Language code: Fortran-77, Fortran-90 and some C, C++ and Python
• A time dependent 1½D tokamak transport data analysis model with generalized non-circular flux surface geometry
• Auxiliary heating packages– NUBEAM, TORIC, LSC, TORAY
PTRANSP
• Predictive TRANSP– The ability of simulating numerous kinds of fusion pla
sma activities– Inputs: Tokamak Simulation Code (TSC) outputs
• Shaped boundary (required)• Other self-consistent plasma parameters (optional)
– The same namelist with different options– Equilibrium: TEQ– Temperature and transport model options: GLF23, M
MM95, Weiland model, NClass neoclassical model, paleoclassical model, etc.
– Density: assumed
Feature of energy transport in NSTX
plasma• Data selection
• dependence at constant Bt
• The influence of plasma current profile on
• The ‘pivot’ phenomenon in profile
• The influence of lithium on energy transport
dependence on Bp (or q)
• Parameters: Ip(900kA),
Bt (0.48T), Pheat(5.6MW), and
<ne> (4.6~5.61013cm-3),
<Te> (490~608eV)• A significant influence of ngTx in the
relation between s and Bp (or q)– ngTx: the abbreviation of ‘local -ne*
Ti/e’ value– units: Bp in T, ne in 1013cm-3, Ti/e in eV, r i
s normalized magnetic surface
• The proportional relation between and Bp (or the inversely proportional relation between and q )
dependence on plasma current
• Pcond vs ngTx and q at constant Bt and different Ip
– No obvious dependence on Ip
– Plasma current profile• Constant ngTx
–
–
• Constant q• Peaky and flat
(hollow) profile
pxIjngTx
pxIq 1
The ‘pivot’ phenomenon in eprofile
• Governed by local current density (or current profile) – Data at constant Bt (2008)
– Data at different Bt (2006) Ip=900kA Ip=1100kA
Data at different Bt (2006)
The influence of lithium on energy transport
• Energy confinement time– Parameters:
• Ip (kA): 800, 900
• Bt (T): 0.54(max), 0.51(avg), 0.48(min)
• Pheat (MW): 4.3(max), 3.7(avg), 3.2(min)
– E increases
– 0mg: without-lithium data
• Radiated power– Local e decreases
– Large percentage of radiated power
– No obvious improvement on i
The influence of lithium on energy transport
• e (direct comparison)– More than 50% reduction
• i (indirect comparison)– Effective
• The third lithium state
Ip: 900kABt: 0.47TPheat: 5MW
Ip: 900kABt: 0.49TPheat: 3.6MW
EAST simulation
• Shot#12467:– 250kA; 1.9T;1.1e19m-3; LSN, DN, USN; Ohmic
• Shot#12755:– 500kA; 1.9T; 2.5e19m-3; DN; PLH: 450kW
• Theoretical transport model:– GLF23 (mainly)– MMM95– RLW-M
EAST simulation: 12467flux contour
A
B
C
D
E
EAST simulation: 12467flux contour
A
B
C
D
E
EAST simulation: 12467flux contour
A
B
C
D
E
EAST simulation: 12467p, li and current profile
• Some difference between TRANSP (TSC) and EFIT
EAST simulation: 12467different models and experiment
data
EAST simulation: 12467ne and Ti/e profile
• ne profile: assumed by using parabolic distribution with two free index parameters
• Ti0: assumed to be 2/3~3/4 Te0
EAST simulation: 12467confinement
EAST simulation: 12467power balance
• Electron:– Source: Ohmic electron heating– Sink: i-e coupling, conduction
• Ion:– Source: i-e coupling– Sink: conduction, charge exchange loss
• The theory model for radiation prediction is not effective enough.
EAST simulation: 12467energy transport
EAST simulation: 12755LH wave injection
• Absorbed LH power: 85% injected LH power, similar to Ohmic power
• Deposition position of LH power: ~0.1 and ~[0.3, 0.65]
EAST simulation: 12755LH current
• IOh: 400kA; ILH: 80kA; IBS: 20kA
• CD=9.95e18 AW-1m-2
EAST simulation: 12755region of LHW
absorption
• 5% LH power was deposited around ~0.1, that can not be explained in this figure.
EAST simulation: 12755theory model and experiment
data
EAST simulation: 12755high power plasma
• ICRH: minority heating scheme
• L-H transition threshold: Ploss~1.1MW
NBI simulation
Summary
• Brief instruction of TRANSP/pTRANSP program• Plasma current profile affects values, including
the ‘pivot’ phenomenon, via ngTx.• Lithium can improve energy confinement time, en
hance radiation and reduce e more than 50% when large quantities are injected. For i, it is effective, but not quantitative investigated.
• The relatively reasonable results are obtained in EAST simulation comparing with experiment data.
• More detailed physical analysis and operation design are under consideration.
Acknowledgement
• PPPLers:– Analysis: Stanley Kaye and the NSTX team– Prediction: Robert Budny– TRANSP settings and jobs monitoring: Dougl
as McCune and the Computational team
• ASIPPers:– Modeling: Xinjun Zhang, Fukun Liu, Jun Li– Experiment data: Ping Xu, Jianhua Yang, Xia
ofeng Han, Jinping Qian– TSC output: Yong Guo
Thank you !