27E13P
改善電子エネルギー閉じ込めに対する電流分布効果に関する
H モードデータベース解析と乱流輸送解析
H-mode Database and Turbulence Analyses of the Current Profile Effect on
Improved Electron Energy Confinement
成田絵美 1、本多充 2、林伸彦 2、滝塚知典 1、井手俊介 2、伊丹潔 2、諫山明彦 2、福田武司 1
E. Narita1, M. Honda2, N. Hayashi2, T. Takizuka1, S. Ide2, K. Itami2, A. Isayama2 and T. Fukuda1
1

阪大院工、2 原子力機構
1
Osaka Univ., 2JAEA
calculations have been performed by the GS2 code [5],been generally observed when the electron temperature Te

paying attention to the magnetic shear s that has a close

exceeds the ion temperature Ti [1]. The International

affinity with the current profile. Figure 3 shows theGlobal H-mode Confinement Database [1,2] has been

calculation results, where the input parameters are  = 0.5,

surveyed with an emphasis on the dependence of the HH

Te0/Ti0 = 1.2, normalized electron and ion temperaturefactor (HH  th/th,IPB98(y,2)) on the temperature ratio at thegradients R/LTe = 6 and R/LTi = 7.5, normalized density

magnetic axis Te0/Ti0. As a consequence, the degradation

gradient R/Ln = 2 and the safety factor q = 1.5, which areof HH factor with an increase in Te0/Ti0 has been found.

consistent with the values from the database, and theThe transport simulations showed that the confinement

wave number ki is 0.3, around which ITG/TE mode has

degradation can be attributed to enhanced transport by

the maximum growth rate. The increase in s significantly

ITG/TEM turbulence [3]. However, as depicted in

reduces the electron heat flux compared to the ion one.

figure 1, however, there are data that have the HH factor

The analyses infer the relationship between the increase

exceeding unity in Te0/Ti0 > 1 region (open circles). In

in s in the core region and0.5

these data, the electron thermal energy is nearly twice

the decrease in li. Based on

0.4

larger than ion one, and the internal inductance li is lower

quasilinear theory and athan that of the other data in Te0/Ti0 > 1 region (open andmodified

closed circles in figure 2). The dataset of these highestimate [6], the electronenergy confinement discharges, which were heated byandNBI, includes the data with Pe/Pi < 1, where Pe and Pi

diffusivities are estimated,

denote NBI power absorbed by the electrons and the ions,which we will present inrespectively. It is suggested that the current profile affects

the paper.

mixingion

lengththermalQe/Qi

The confinement degradation of H-mode plasmas has

GS2

turbulent transport, the gyrokinetic linear stability

R/LTe

0.2

R/LTi=k  =0.3
0.1  i
0.5

R/Ln=
1
s

3

high HH

high HH

db3-v13-JET.AUG.JT60U.DIIID.CMOD

middle HH

B''=1

TAUTH/IPB98(y,2)

2.5

middle HH

db3-v13-JET.AUG.JT60U.DIIID.CMOD

low HH

B''=1.5

TAUTH/IPB98(y,2)

References[1] Progress in the ITER Physics Basis, Chapter 2: Plasma

2low HHW [MJ]

HH

db3-v13-JET.AUG.JT60U.DIIID.CMOD

1TAUTH/IPB98(y,2)

11.2

1.4 1.6
Te0/Ti0

1.8

1.5
1.5

Figure 1 The plot of HH
factor as a function oftemperature ratio at themagnetic axis.

1IP~2.5MA 14points low HHq < 4.5include WIKIN

128 (1995). Source program is downloaded fromhttp://www.gs2.sourceforge.net/

33

2.5
2.522

1.5
1.5
11

1.6
1.6

IP~2.5MA 6points middle HH

1.1 1.2

0.5
0.5
1.4
1.4

WEKIN [MJ]WIKIN [MJ]

[5] M. Kotschenreuther et al., Comp. Phys. Commun. 88,

0.8 0.9
li

1

1.2
1.2

WEKIN [MJ]WIKIN [MJ]

[4] The ITER 1D Modeling Working Group, Nucl. Fusion

db3-v13-JET.AUG.JT60U.DIIID.CMOD

40, 1995 (2000).

Figure 2 The dependence ofthermal energy on internalinductance.

10.5
0.5 1
1IP~2.5MA 15points high HH[3] E. Narita et al., Plasma Fusion Res. 7, 2403102 (2012).

db3-v13-JET.AUG.JT60U.DIIID.CMOD

open: Wi

Ip ~ 2.5MA

q<4.5 0including
Wi 0.70.6

2closed: We

10.5

0.5

B''=21.5[2] http://efdasql.ipp.mpg.de/hmodepublic/

db3-v13-JET.AUG.JT60U.DIIID.CMOD
WEKIN [MJ]WIKIN [MJ]

1.8
1.8

22

00
0.6
0.6

0.7
0.7

0.8
0.8

0.9
0.9

11

1.1
1.1

1.2
1.2

1.5

Figure 3 The dependence ofheat flux ratio on magnetic
shear from GS2.

confinement and transport, Nucl. Fusion 47, S18 (2007).
1.5abs(heat fTe/Ti=0.3

the electron heat transport.
In order to study a role of the current profile ings2-case219-2[6] J. Weiland Collective Modes in Inhomogeneous Plasma(Bristol: Institute of Physics Publishing) (2000).

ki=