N ATIONAL R E S E A R C H CENTRE“Kurchatov institute”
NRC KIINSTITUTE OF TOKAMAK PHYSICSASTRA simulations of ITER
long pulse scenarios
V. Leonov
Kurchatov Institute, Moscow, Russia

7th Integrated Operation Scenarios Topical Group Meeting
Kyoto, Japan, 18-21 October 20111

Motivation•The work have been done in the modeling activity IOS-JA9 which
includes: to find the operational space for long pulse operation toobtain the optimal parameters for this operation. (A. Polevoi - IO)

Phase I (A. Polevoi)
Assessment of operational space (OS) (Ip, n, etc.) for long-pulse
operation by 1.5D modelling(0) Start from ITER inductive baseline scenario(Ip=15 MA, Pfus =500 MW, Q = 10, ∆tFT =400 s)(1) Keeping the same input and assumptions as for 500 MW baseline scenario
with basic set of CD: 16.5 MW on- + 16.5 MW off-axis NBCD+ 20 MW ECCD--- Density scan for each of the models
Phase II (A. Polevoi)
Sensitivity studies for modelling assumptions (pedestal, Zeff, n(0)/<n>, etc)
In this presentation: Sensitivity to high-Z impurity contamination (W, Ar)
V. Leonov 7th IOS TG Meeting 18-21 Oct. 2011, Kyoto, JapanNATIONAL RESEARCH CENTRE «KURCHATOV INSTITUTE»
INSTITUTE OF TOKAMAK PHYSICS

2

Simulations have been carried out with the ASTRA transport codewith fixed boundary equilibrium- empirical scaling-based plasma transport model- in the pedestal region (ρρN > 0.94) transport coefficients decrease toχiNC level- He pumping speed was selected to keep τHe / τE = 3 at 15 MA- Boundary conditions: Tes = 0.2keV, nes = 0.3 <ne>,- impuririties:1) prescribed impurity density profiles ~ ne profile + radiation (in thecoronal approximation)2) simulation of impurity ionization state, transport (including NC
by NCLASS code) and radiation by ZIMPUR impurity code(boundary impurity flux was selected to produce necessaryimpurity contamination)- Flat-top length: ∆tFT = ∆Ψ[Vs]/ Ures[V] = (240-14*Ip) / Ures; Ures= POH/IP∆Ψ
Fl =0.8*Pfus*∆∆tFT
V. Leonov 7th IOS TG Meeting 18-21 Oct. 2011, Kyoto, JapanRUSSIAN RESEARCH CENTRE «KURCHATOV INSTITUTE»
INSTITUTE OF TOKAMAK PHYSICS

31015MAQ

8Fluence (10 MJ)/pulse

Plasma current – density scan for long pulse operation
ind

644131023000∆ t (s)15MA

500400300
200
10001015MA

1002.015MA

βN

1061.015MA
ind

8 19 -310n e (10 m )

120.0
2.0

15MA

1.5

ind

100.5468 19 -3 10n e (10 m )V. Leonov 7th IOS TG Meeting 18-21 Oct. 2011, Kyoto, Japan-- at Ip=10MA, ne ~5 1019m-3∆t ~ 1 hour, total Fl as in
15MA scenario(small power intensity)

131.00.0• HH = 1• nAr / ne =0.12%nBe / ne =2.0%

0.51 hour1313 ind

10• Start from 15MA 500MW
scenario•
H&CD:
16.5MW on +16.5MW off-axis
NBI + 20 MW ECR

51.5101000
42015ind

131320000ind

P loss / P LH

Pfus (MW)025

12

NATIONAL RESEARCH CENTRE «KURCHATOV INSTITUTE»
INSTITUTE OF TOKAMAK PHYSICS

4Q

8Hybrid
Ip=13.5MA

642Q~5500400
300
20010002000

referenceparameters
boundary

H-modeboundary

P loss / P LH

∆ t (s)Pfus (MW)01500
1000500 ∆ t ~ 1000s
00P rad (MW)10Fluence (104MJ/pulse)

Sensitivity study (performance dependence on W contamination)

13nW / n e (10 %)-34nAr = 0.
nBe / ne= 2.0% (by boundary flux)

20
10HH = 1.05060

2 limits :40

1 – boundary of reference
parameters (Q ~ 5; ∆t ~ 1000s)

20

at nW / ne ~ 0.002%

02.0

H-modeboundary

1.5
1.00.52ASTRA + ZIMPUR

300.00at nW / ne > 0.0027- 0.003%

P loss / P LH ~ 112 -3 3nW / n e (10 %)V. Leonov 7th IOS TG Meeting 18-21 Oct. 2011, Kyoto, Japan

2 – more strong limit(danger of H L-mode transition)

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NATIONAL RESEARCH CENTRE «KURCHATOV INSTITUTE»
INSTITUTE OF TOKAMAK PHYSICS

5Q~ 5Hybrid
Ip=13.5MA

2Pfus (MW)

0200
10002000∆ t (s)H-modeboundary

300

1500

referenceparameters
boundary∆ t ~ 1000s

1000
500
00.10

P rad (MW)Q

4P loss / P LH

6Fluence (104MJ/pulse)

Sensitivity study (performance dependence on Ar contamination)30
20

HH = 1.05
102 limits :
060

0.20
0.25nAr / n e (%)

1 – boundary of referenceparameters (Q ~ 5; ∆t ~ 1000s)

40

at nAr / ne ~ 0.12%

2002.0H-modeboundary

1.52 – more strong limit(danger of H L mode transition)
at nAr / ne > 0.2%

1.00.50.15

nW = 0.
nBe / ne= 2.0% (by boundary flux)

0.00.10

P loss / P LH ~ 10.15-- narrow nAr region to control Prad

0.20
0.25
nAr / n e (%)

V. Leonov 7th IOS TG Meeting 18-21 Oct. 2011, Kyoto, JapanNATIONAL RESEARCH CENTRE «KURCHATOV INSTITUTE»
INSTITUTE OF TOKAMAK PHYSICS6

Summary and future work
• Results of the plasma current-density scan (starting from thebasic inductive scenario) for comparison with other models andcodes are presented -- work in progress and will be continued.
• Investigation of impurity influence to hybrid scenario
performance shows high sensitivity to high-Z impurity (W, Ar)
contamination (narrow operation region) -- work will be continued
for other impurities (Be,C,Ne) and discharge parameters.
• OS and sensitivity analysis for SS scenarios will be started also.

V. Leonov 7th IOS TG Meeting 18-21 Oct. 2011, Kyoto, JapanRUSSIAN RESEARCH CENTRE «KURCHATOV INSTITUTE»INSTITUTE OF TOKAMAK PHYSICS7