introduction of hl-2m divertor design - iaea na€¦ · hl-2a cs and pf coil parameters of hl-2m...

HL-2A

G.Y. Zheng1, X.R. Duan1, X.Q. Xu2, D.D. Ryutov2, L.J. Cai1, X.

Liu1, J.X. Li1, T.Y. Xia3, Y.Y Lian1, L. Xue1, Y.D. Pan1 and B. Li1

1Southwestern Institute of Physics, Chengdu, China

2Lawrence Livermore National Laboratory, Livermore, USA

3Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China

Introduction of HL-2M divertor design

Vienna, 29 September – 2 October 2015

The 1st IAEA Technical Meeting on Divertor Concepts

HL-2A

Content

1. Configuration design of HL-2M

2. Properties of divertor configurations

3. Divertor target geometry and simulation

4. Engineering design and X-point control

5. Plan and summary

HL-2A

•R: 1.65 m

•a: 0.40 m

•Bt: 1.2~2.7 T

•Configuration:

Limiter, LSN divertor

• Ip: 150 ~ 480 kA

•ne: 1.0 ~ 6.0 x 1019 m-3

•Te: 1.5 ~ 5.0 keV

•Ti: 0.5 ~ 2.8 keV

Heating:

ECRH/ECCD: 5 MW

(6 X 68 GHz/0.5MW/1s, 2 X 140 GHz/1W/1s)

NBI (tangential): 3 MW

LHCD: 2 MW (4/3.7 GHz/500 kW/2 s)

Diagnostics: over 30, e.g. CXRS, MSE, ECEI…

Fuelling system (H2/D2): Gas puffing (LFS, HFS,

divertor), Pellet injection (LFS, HFS),

SMBI /CJI (LFS, HFS)

LFS: f =1~80 Hz, pulse duration > 0.5 ms

gas pressure < 3 MPa

HL-2A

HL-2A

Plasma current Ip = 2.5 (3) MA

Major radius R = 1.78 m

Minor radius a = 0.65 m

Aspect ratio R/a = 2.8

Elongation Κ = 1.8-2

Triangularity δ > 0.5

Toroidal field BT = 2.2 (3) T

Flux swing ΔΦ= 14Vs

Heating power 25 MW

Main parameters

HL-2M (new tokamak, under construction)

HL-2M tokamak

Mission: high performance, high beta, and high bootstrap

current plasma; advanced divertor (snowflake, tripod), PWI.

HL-2A

Test the engineering and physics issues

relevant to to fusion reactor, such as ITER

and CFETR.

Heat flux at target can be roughly compared,

(total heating power is 25MW, λq less than

2mm with Ip = 3MA).

HL-2M

Mitigation of heat flux at target to support

HL-2M high performance operation.

High performance plasma and advanced divertor

HL-2A

CS and PF coil parameters of HL-2M

R(mm) Z(mm) W(mm) H(mm)Ncoil

(Nr×Nz)

Max(kA)

PF1 912 185 50.4 352.4 28(2×14) 14.5

PF2 912 586 50.4 352.4 28(2×14) 14.5

PF3 912 987 50.4 352.4 28(2×14) 14.5

PF4 912 1388 50.4 352.4 28(2×14) 14.5

PF5 1092 1753 183 220 28(5×6) 38

PF6 1501 1790 257 146 27(7×4) 39.41

PF7 2500 1200 183 220 28(5×6) 39

PF8 2760 480 183 220 28(5×6) 35.29

CS 748 0 116.75 3442.3 96(2×48) 110

HL-2M

CS and PF coil parameters of HL-2M

All of PF Coil current can be reversed for HL-2M

HL-2A

Standard divertor to advanced divertor

PF4/L and PF6/L as divertor coils to generate two

separate X-points;

PF5/L adjusts position of the two X-points to

satisfy design requirements, such as snowflake

divertor configuration.Standard divertor

HL-2M

Snowflake Tripod

HL-2A

Ip(MA) R (m) a (m) Κ δ up δ down li βp

EFIT 1.2 1.71 0.56 1.698 0.265 0.735 1.17 0.645

CORSICA 1.2 1.71 0.55 1.694 0.255 0.745 1.17 0.64

EFIT CORSICA

Equilibrium benchmark by EFIT and CORSICA

HL-2A

Standard divertor Exact SF divertor SF divertor-plus SF divertor-

minus

Ip(MA) R (m) a (m) Κ δ up δ down li βp

2.0 1.78 0.62 1.73 0.3 0.74 1.20 0.60

Snowflake configurations of HL-2M

HL-2A

Exact-SF

When the plasma current reduces, the second X-point is fixed and first X

point is forced to moved up by take advantage of poloidal field of CS coil:

When plasma current is 0.9MA, the distance between the X-points will be

more than 50cm.

SF-minus Tripod Tripod

Snowflake divertor to Tripod dievrtor

HL-2A

Standard divertor

Weak Bp region of HL-2M SF divertor

Exact-SFStandard SF-plus SF-minus

D.D. Ryutov, et al., Contrib. Plasma Phys., 52, 539, 2012; PPCF, 54, 124050, 2012.

Fast convective heat transport around

weak Bp can increase power sharing

among the divertor legs and broaden

the heat flux profile at target.

HL-2A

Weak Bp region of HL-2M SF/Tripod divertor

When the distance between the two X-points

becomes large, configuration loses features of

snowflake divertor, becoming just two

separate X-points;

Tripod configuration has a long divertor leg

and three outgoing branches of the separatrix.

HL-2AThe local shear

The integrated magnetic shear

Magnetic shear and curvature analysis of SF

Same main parameters, R, a, Ip, k95, q95.

Same pressure and current profiles.

(Local magnetic shear)

Radius of curvature on outer mid-plane

HL-2A

The linear growth rate

Snowflake-minus improves P-B mode instability

The snowflake-minus has the closest X-point to the outer mid-plane

is able to affect the property of ballooning modes.

The second X-point improves the bad curvature in favor of the

suppression of P-B modes.

HL-2A

SF

SD

The TQ and the CQ phaseThe hot vertical displacement phase

Configuration evolution during VDE

Parameters Ip (MA) R0 (m) a (m) κ95 βp li δ95 Bt (T)

Value 1.00 1.71 0.55 1.65 0.60 1.06 0.25 2.20

HL-2A

30cm

The configurations (standard,

snowflake and tripod) of HL-2M can

be explored by optimizing the target

geometry;

High cooling ability to support the

high heat flux operation;

Flexible support structure, and well

protection for cooling pipe system;

Easy installation, maintenance and

update.

Divertor engineering design consideration

HL-2AStandard divertor Exact snowflake Snowflake minus

Target plate geometry of HL-2M

Divertor target geometry is expected to be compatible with the

configurations of HL-2M.

Ip=2MA Ip=2MA

HL-2A

Bp / Bt value around target of HL-2M divertor

γmin ≈ Bp/Bt sinα., if γmin too small,

the shadows and hot spots may

appear on the plate;

γmin is assumed to be 1/50 of a

radian (roughly 1 degree).

Standard divertor

Exact snowflake

Snowflake minus

HL-2A

Connection length

If λq=2mm of HL-2M, the plasma-wetted area:

more than 1.5m2 of SF and about 0.3m2 of SD;

P=12MW, 8MW/m2 of SF, 40MW/m2 of SD.

Standard divertor Snowflake minus

Mesh of SD and SF

0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.0400.0

0.5

1.0

1.5

2.0

2.5

Rati

o o

f co

nn

ecti

on

len

gth

Distance from separatrix at outer middle plane (m)

Standard divertor

Snowflake divertor

Surface expansion

0.00 0.01 0.02 0.03 0.040

20

40

60

80

100

120

140

Su

rface e

xp

an

sio

n

Distance from separatrix at outer middle plane (m)

Standard divertor

Snowflake divertor

Ip=2MA Ip=2MA

HL-2A

Simulation boundary conditions of SD and SF

Cross field transport factor: D = 0.2m2/s, χe = χi = 0.5m2/s;

Power flows into SOL/Divertor regions: P = 12MW,

Pi=Pe=6MW;

The density is fixed about 4cm inside the separatrix, and the

upstream density ne,sep = 2.5*1019/m3;

The pumping gas speed S=50m3/s;

Carbon as impurity is included;

When Ip=2.0MA, the plasma density limit is about 1.5*1020/m3.

HL-2A 2MW/m2 of SF, and about 5.8/m2 of SD.

Heat flux distribution of SD and SF

The heat flux distribution at outer

target of standard divertor

The heat flux distribution at outer

target of snowflake minus

0.0 0.1 0.2 0.3 0.4 0.5 0.6

0

1x106

2x106

3x106

4x106

5x106

6x106

He

at

flu

x W

/m2

Distance from separatrix at outer target (m)

Standard divertor

Snowflake divertor

Heat flux profiles at outer target

HL-2A

Electron density at outer target

Electron density at outer target of SD and SF

0.0 0.1 0.2 0.3 0.4 0.5 0.6

0.0

2.0x1020

4.0x1020

6.0x1020

8.0x1020

1.0x1021

1.2x1021

1.4x1021

De

ns

ity

(/m

3)

Distance from separetirx at outer targte (m)

Standard divertor

Snowflake divertor

Standard divertor

Snowflake minus

HL-2A

Carbon ion density distribution of SD

C4+ C6+C5+

C3+C2+C1+

HL-2A

C3+C2+C1+

C4+ C6+C5+

Carbon ion density distribution of SF

HL-2A

Zeff distribution of SD and SF

0 20 40 60 80 1001.0

1.5

2.0

2.5

3.0

Zeff

From inner target along poloidal direction to ourter target

Standard divertor

Snowflake divertor

Inner target

Near X point

Outer mid-plane

Near X point

Outer target

Standard divertor

Snowflake minus

HL-2A

Peak heat flux at outer target of SF and SD

8 10 12 14 16 18

1x106

2x106

3x106

4x106

5x106

6x106

7x106

8x106

He

at

flu

x (

W/m

2)

Power flows into SOL/Divertor region (MW)

Standards divertor

Snowflake divertor

2.1x1019

2.4x1019

2.7x1019

3.0x1019

3.3x1019

2.0x106

4.0x106

6.0x106

8.0x106

1.0x107

1.2x107

Standard divertor

Snowflake divertor

He

at

flu

x

(W/m

2)

Electron density at outer mid-plane (m3)

The peak heat flux of SF is about 35% of SD (P=8-18MW);

ne,sep = 2.0*1019/m3，2.3MW/m2 of SF, 10.8MW/m2 of SF.

Peak heat flux at target with different

power flows into SOL/Divertor region

Peak heat flux at target with different

Electron density at outer mid-plane

P=12MW

HL-2A

SF and Tripod divertor configurations, Ip = 0.5MA

Snowflake minus Tripod 2Tripod 1

Ip = 0.5MA Ip = 0.5MA Ip = 0.5MA

HL-2A

D = 0.3m2/s, χe = χi = 1.0m2/s; P = 8MW, Pi = Pe = 4MW;

ne,sep = 1.4*1019/m3; Pumping speed is 50m3/s;

Carbon as impurity is included.

Mesh and boundary conditions of SD and SF

Snowflake minus TripodTripod

Ip = 0.5MA Ip = 0.5MA Ip = 0.5MA

HL-2A

0.00 0.01 0.02 0.03 0.04 0.05

10

20

30

40

50

60

70

Su

rfa

ce

ex

pa

ns

ion

Distance from separatrix at outer mid-plane (m)

Standard divertor

Snowflake minus (YX-point

= 120cm)

Tripod 1 (YX-point

= 110cm)

Tripod 2 (YX-point

= 100cm)

Connection length and surface expansion

Ratio of connection length of four

kinds divertor configurationSurface expansion of four kinds

divertor configuration

0.00 0.01 0.02 0.03 0.04 0.05

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

Rati

o o

f co

nn

ecti

on

len

gth

Distance from separatrix at outer mid-plane (m)

Standard divertor


= 120cm)

Tripod (YX-point

= 110cm)

Tripod (YX-point

= 100cm)

HL-2A

Heat flux distribution of SF and Tripod

0.0 0.1 0.2 0.3 0.4 0.5 0.6

0

1x106

2x106

3x106

4x106

5x106

Heat

flu

x (

W/m

2)

Distance from separatrix at outer target (m)

Standard divertor


= 120cm)

Tripod (YX-point

= 110cm)

Tripod (YX-point

= 100cm)Snowflake minus

Tripod 2

Tripod 1Standard divertor

HL-2A

Zeff distribution of different configurations

Snowflake minus Tripod 2Tripod 1Standard divertor

HL-2A

Carbon ion density distribution

C4+ C6+C5+

C4+ C6+C5+

Snowflake minus

Tripod 2 Tripod 2 Tripod 2

Snowflake minus Snowflake minus

HL-2A

-0.05 0.00 0.05 0.10 0.15 0.20 0.25

0.0

2.0x105

4.0x105

6.0x105

8.0x105

1.0x106

1.2x106

1.4x106

1.6x106

1.8x106

He

at

flu

x (W

/m2

)

Distance from the separatrix (m)

Ip=1.2MA

Ip=0.9MA

Ip=0.7MA

-0.05 0.00 0.05 0.10 0.15 0.20 0.25

0.0

2.0x105

4.0x105

6.0x105

8.0x105

1.0x106

1.2x106

1.4x106

1.6x106

1.8x106

He

at

flu

x (W

/m2)


Ip=1.2MA

Ip=0.9MA

Ip=0.7MA

-0.05 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45

0.0

2.0x105

4.0x105

6.0x105

8.0x105

1.0x106

1.2x106

1.4x106

1.6x106

1.8x106

He

at

flu

x (W

/m2

)


Ip=1.2MA

Ip=0.9MA

Ip=0.7MA

-0.05 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45

0.0

2.0x105

4.0x105

6.0x105

8.0x105

1.0x106

1.2x106

1.4x106

1.6x106

1.8x106

He

at

flu

x (W

/m2

)Distance from the separatrix (m)

Ip=1.2MA

Ip=0.9MA

Ip=0.7MA

Ip = 0.7MA

P =10MW

ne= 1.5X1019/m3

Heat flux at targets of DN tripod divertor

Limit the power flows into inner divertor region.

Handle most of heating power by outer divertor.

HL-2A

Vacuum VesselFirst wall Divertor

Divertor and first wall engineering design

First wall: Graphite;

Target plate: CFC.

HL-2A

Divertor engineering design and fabrication

Cassette divertor structure of HL-2M

CFC as the plasma

facing material brazed on

the copper alloy heat sink;

Cooling and baking

channels are drilled inside

the target copper plates to

feed cooling water;

Channels are connected

to pipes embedded inside

the support frame;

Design of diveror structure: 80 sections, cassette, individual

cooling, link structure for stress release

HL-2A

In-vessel and ex-vessel cooling circuits Feeding and collection pipes

Cooling design and analysis

Variation of highest CFC temperature with time

10MW/m2, 5s

HL-2A

Development of W coatings on graphite and CFC

HL-2A

P0

P1

P3

P2

X2

X1

exp exp( , , )C x y

Locally expand the Grad-Shafranov equation:

X-points Control methods

Find coefficients, Cexp, with the Br and Bz at points(P0-P3) from RTEFIT

Control X1, X2, ρ and θCreated the relationship between the PF coils

current and the X-point locations:

1( )T T

PFI A A A W B

1 1 2 2[ , , , , ]

iso

T

iso

GA

X P G

B x y x y

where,

exp exp

exp

1 1 r z

PF r PF z PF

C CB Bx x

I C B I B I

X, P , G

2

20r

r r r z

So

HL-2A

Controlling the distance between two X-points

文件

文件 snow2 装置 HL-2M 炮号 99996 时间 0

模式

迭代误差 4.6e-03 迭代次数 22 运行模式平衡模式收敛与否已收敛/ 1.0e-03 / 50

位形

位形中心r 1.798 位形中心z -0.099 小半径 0.606 位形下单零

上三角形变 0.326 下三角形变 0.784 截面积 1.906 体积 20.729

上拉长比 1.570 下拉长比 2.021 边界磁通 -0.283 磁轴磁通 0.246

电流

IPF1 -11.60 IPF2 -12.03 IPF3 -0.89 IPF4 4.53 IPF5 -7.82 IPF6 0.22 IPF7 -17.51 IPF8 -9.54


IP 2000.00 IE -39.56

1 1.5 2 2.5

-1.5

-1

-0.5

0

0.5

1

1.5

Control two X-points

文件文件 snow2 装置 HL-2M 炮号 99996 时间 0

模式

迭代误差7.4e-03 迭代次数 20 运行模式平衡模式收敛与否已收敛/ 1.0e-03 / 50

位形


上三角形变0.288 下三角形变0.790 截面积 1.826 体积 20.046


电流IPF1 -12.21IPF2 -12.03IPF3 -0.54 IPF4 4.52 IPF5 -7.96 IPF6 -0.04 IPF7 -17.13IPF8 -9.89

IPF9 -9.43 IPF10 -18.95IPF11 6.09 IPF1215.70IPF13 -31.78IPF1419.09IPF15 -19.41IPF16 -16.06

IP 2000.00IE -39.56

0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8

-1.5

-1

-0.5

0

0.5

1

1.5

0 5 10 15 20-800

-600

-400

-200

0

200

400

sum

__delt__Ip

f(A

)

dIPF1U

dIPF2U

dIPF3U

dIPF4U

dIPF5U

dIPF6U

dIPF7U

dIPF8U

0 5 10 15 20-1.5

-1

-0.5

0

0.5

1

1.5x 10

4

sum

__delt__Ip

f(A

)

dIPF1L

dIPF2L

dIPF3L

dIPF4L

dIPF5L

dIPF6L

dIPF7L

dIPF8L

PF5

PF3

PF2

PF6

0 2 4 6 8 10 12 14 16 18 20-50

0

50

100

150

200

R-Z

(mm

)

The different of Xpoints' position from the target points

dRX1

dZX1

dRX2

dZX2

dRX = RX-target - RX-cur

dZX = ZX-target - ZX-cur

HL-2A

0 2 4 6 8 10 12 14 16 18 20-20

0

20

40

60

80

100

R-Z

(mm

)

The different of Xpoints' position from the target points

dRX1

dZX1

dRX2

dZX2

Controlling the second X-point

文件

文件 snow2 装置 HL-2M 炮号 99996 时间 0

模式

迭代误差 4.6e-03 迭代次数 22 运行模式平衡模式收敛与否已收敛/ 1.0e-03 / 50

位形


上三角形变 0.326 下三角形变 0.784 截面积 1.906 体积 20.729


电流



IP 2000.00 IE -39.56

1 1.5 2 2.5

-1.5

-1

-0.5

0

0.5

1

1.5

dRX = RX-target - RX-cur

dZX = ZX-target - ZX-cur

0 5 10 15 20-400

-300

-200

-100

0

100

200

300

sum

__delt__Ip

f(A

)

dIPF1U

dIPF2U

dIPF3U

dIPF4U

dIPF5U

dIPF6U

dIPF7U

dIPF8U

0 5 10 15 20-8000

-6000

-4000

-2000

0

2000

4000

6000

8000

sum

__delt__Ip

f(A

)

dIPF1L

dIPF2L

dIPF3L

dIPF4L

dIPF5L

dIPF6L

dIPF7L

dIPF8L

PF5

PF3

PF2

PF6

Control the second X-points

HL-2A

Phase I: no feedback control, plasma vertical position grows exponentially

Phase II: feedback control of plasma vertical position start at the same time

k95 1.53 1.56 1.58

Growth rate 169 177 186

k95 1.55 1.58

Growth rate 162 208

I II

k95=1.58

I II

k95=1.58

SF SD

VDE control analysis of SF and SD divertor

HL-2A

Complicate configurations of HL-2M

More codes be involved in HL-2M divertor design and analysis,

such as SOLPS-ITER, EMC3, SOLEDGE and so on. The affect of

the second X-point will be investigated.

HL-2A

According to the lower divertor operation results, the upper

divertor will be designed and installed;

Based on the W coating technology developed at SWIP, the

first wall and target plate with W coating will be carried out

step by step;

The PWI researches based on HL-2M advanced divertor will

be studied, as well as the compatibility with the high

performance core plasma operation;

The particle control ability of HL-2M will be enhanced.

Possible divertor engineering update

HL-2A

Summary

Divertor configurations, properties analysis, target design,

divertor simulation, engineering design and configuration

control works are carried at SWIP for HL-2M divertor design.

Based on the design and analysis, standard and advanced

divertors will be are explored in HL-2M experimental research

project to study the divertor physics and mitigate heat flux for

high heating power operation.

Advanced divertor is an important mission of HL-2M, the

divertor physics, engineering design, code simulation and so on

are challenges for us now.

HL-2A

Thank you!

introduction of hl-2m divertor design - iaea na€¦ · hl-2a cs and pf coil parameters of hl-2m...

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