(SG2) Tronsport and Confinement Report
Date: Jun. 5, 2024
Time: 13:39 - 14:39
Shot#: #192646 – #192689 (44 shots)Jun. 6, 2024 (A. Shimizu)

Prior wall conditioning: H
Divertor pump: YES
Gas puff: H2
IPD: OFF
NBI#(1, 2, 3, 4, 5)=gas(H, H, H, H, H)=P( 4.4, 4.1, 4.3, 3.3, 2.6)MWECH(77GHz)=ant(5.5-Uout (or 1.5U), 2-OUR)=P(698, 380)kW
ECH(154GHz)=ant(2-OLL, 2-OUL , 2-OLR)=P(705, 806, 982)kW
ECH(56GHz)=ant(1.5U)=P(-)kW
ICH(3.5U, 3.5L, 4.5U, 4.5L)=P(0.0, 0.0, 0.0, 0.0)MWTopics
1. The study of the density dependence of ion transport in LHD for ITER operation (Ko. Won-Ha, K. Ida, M.
Yoshinuma)
2. Real-time plasma control under low-turbulence conditions focusing on turbulent transition (T. Kinoshita, K.
Tanaka)1

Real-time plasma control under low-turbulence conditions focusing on turbulent transition
T. Kinoshita(Kyushu Univ.), Y. Morishita(Kyoto Univ.), N. Kenmochi,
H. Funaba, K. Tanaka, H. Sakai (Kyushu Univ.)

Shot No: #192646~192665 (20shots)Experimental conditions: (Rax, Polarity, Bt, γ, Bq) = (3.6 m, CW, 2.75 T, 1.2538, 100 %)Gas-puff: HControl plans
Plan A: Temperature control by ECRH under constant density
conditions
Plan B: Density control by gas-puff under constant heating
conditions
Plan C: Density control by gas-puff under constant temperature
conditions

ne=4.20Te-5.28(x1019m-3)

Background & Motivation
A turbulence and its driven anomalous transport areminimized when the dominate turbulence mode changes inLHD. The condition of turbulence transition is expressed by
ne=4.20Te-5.28. The final target of this study is to realize alow-turbulence plasma by real-time plasma control.

Plan BPlan A

Plan C(kev)Real-time plasma control under low-turbulence conditions focusing on turbulent transition
Detail of plan A
Temperature control by ECRH underconstant density conditions
Real-time TS
ne, TeAurora TSUBASA

ECRH

Typical result of Plan A・The plasma was operated to satisfy the TT conditions,and at the same time turbulence was reduced.
77 2OUR 154 2OLR

Calculate Te tgt
Te tgt=0.238ne+1.26
Select ECRH
combination
based on difference
between current Te
and target Te

154 2OUL 154 2OLL・The base heating power (NBI#1#3) is solarge that Te<2kev could not be accessed.
0.20

normalized
turbulence amplitude(a.u.)

plasmaResults
・Checked the control system for Plans A-C. Plans A and B
worked well.
・Plan C will be reconfirmed for the system.

Base heating
NBI#1#3
0.15

0.10

0.05

0.00

?
4.0

4.5
5.0time(s)5.5The study of the density dependence of ion transport in LHD for ITER operation
Won-Ha Ko, Jekil Lee(KFE), K. Ida and M. Yoshinuma(NIFS)

Experiments : #192676 ~ #192689
Experimental conditions:(Rax, Polarity, Bt, γ, Bq) = (3.55 m, CW, 2.7887 T, 1.2538, 100.0%)

Objective and background: We would like to search Ti changes as PNBI
increases in high-ne ECH-driven L-mode plasma
in order to find how to increase Ti in ITER
operation.
 The ion transport will give clue by PNBI scan in highdensity (5x1019m-3) plasma sustained by ECH
heating.

Results:
 Ti saturated when PNBI is more than 14MW and nomatter how high the beam power is, Ti/Te ratio
is constant at high-ne (5x1019m-3) and fixed ECHpower (2.8 MW).
 The ion transport effect at high density is very low
since the Ti/Te ratio is almost constant at even highdensities of 5 x 1019 m-3 or higher.

ne,bar=5x1019m-3

ne,bar=5x1019m-3

Fixed PECH=2.8MW

Fixed PECH=2.8MW

Fixed PECH=2.8MW
PNB=20MW

Fixed PECH=2.8MW
PNB=20MW