(SG1) Multi-phase and Atomic/Molecular physics group reportMar. 29, 2024 (M. Kobayashi)
Date: Mar. 28, 2024
Time: 10:30 -16:45
Shot#: 188377 – 188499 ( 123 shots)
Prior wall conditioning: No
Divertor pump: Off
Gas puff: H2, Ne, Ar IPD: No
LID: No
NBI#(1, 2, 3, 4, 5)=gas(H, H, H, H, H)=P(3.8, 4.2, 4.1, 3.9, 2.7) MW
ECH(77GHz)=ant(5.5-U, 2-OUR)=P(698, 380)kW
ECH(154GHz)=ant(2-OLL, 2-OUL, 2O-LR)=P(705, 806, 982) kW
ECH(116GHz)=ant(2O-LR)=P(-)kW
ECH(56GHz)=ant(1.5-U)=P(-)kWICH(3.5U, 3.5L, 4.5U, 4.5L) = P(-, -, -, -) MWTopics
1. Study of edge impurity transport by utilizing multiple spectroscopy diagnostics (T. Nishizawa)
2. Impurity behaviour study in LHD plasmas using VUV spectroscopy in experiment with W TESPEL injections (T. Fornal)
1

Impurity flow reveal in open field lines(T. Nishizawa, T. Kobayashi, M. Kobayashi, Y. Yoshinura, T. Oishi, and K. Ida)
Shot #: 188379 – 188451 Mar 28, 2024
objective: To measure the upstream flow of impurities driven by thermal forceC^3+ toroidal velocity (EMC3-eirene)
Low density

method: The toroidal velocity of C^6+ and bulk ions near the LCFS aremeasured by using CXS.
Done: Density has been scanned at Rax=3.6 m for three different condition.
1. Full power of parallel NBIs
2. Half power of parallel NBIs
3. With Neon puff
#188402 ne~1e+19 m^-3 low

High density

S. Dai et.al. Nucl. Fusion (2018)

EMC-eirene CCXS 529nm spectra, flow seems to be similar in the verticaldirection
Not consistent with EMC3-eirene.

Impurity behaviour study in LHD plasmas using VUV spectroscopy in the W TESPEL injection experiment(T. Fornal, N. Tamura, M. Gruca, M. Kubkowska, C. Suzuki et al.)Magnetic configuration: (Rax, Polarity, Bt, γ, Bq) = (3.60 m, CCW, 2.75 T, 1.2538, 100.0%)
Shots: #188455 - #188489
Background In the recent LHD experiment, some successful TESPEL injections containing W were performed for an electron density of
1 – 5 ×1019 m-3. Some experimental discharges suffered from fragmented TESPEL capsules. The main goal of thisexperiment was to check if the accumulation of W is observed, as in the previous experiments in D, and to study theimpurity transport time of W in LHD plasmas. The obtained results, which we eagerly anticipate, will be compared with
future results in W7-X. The injection of W allowed us to study impurity behaviour in various plasma conditions. The next
step will be to analyze the collected data and perform numerical simulations using Flexible Atomic Code.
Objectives
 Estimate the impurity decay time of W based on the corresponding line intensity evolution.
 Estimate the impurity decay time based on the line intensity evolution for various electron densities of plasma (1-5E19 m-3).
 Estimate the impurity decay time based on the line intensity evolution for various W tracer amounts (0.5-3E17).
 The identification of the spectra will be supported by the simulations using Flexible Atomic Code (using the CollisionalRadiative CR model).

Impurity behaviour study in LHD plasmas using VUV spectroscopy in the W TESPEL injection experiment(T. Fornal, N. Tamura, M. Gruca, M. Kubkowska, C. Suzuki et al.)Results
 TESPELs are successfully injected into the EC+NBI-heated LHD H plasmas
with ne in the range of 1.5 - 4.5E19 m-3
 Apart from density scan – also scan over tracer amount was performed (in the range of 0.5 - 3.0E17 particles) Density scan over various tracer amounts was possible to achived.
nW ¥ ne
0,5
1,0
2,0
3,0

1.5E192.5E194.5E19×✓×✓✓✓✓✓✓×✓✓ Some discharges were not performed successfully; however, the collected data
should contain useful information to be analyzed in the next step.
SOXMOS spectra analysis and their simulation with FAC  to be performed.

Impurity behaviour study in LHD plasmas using VUV spectroscopy in the W TESPEL injection experiment(T. Fornal, N. Tamura, M. Gruca, M. Kubkowska, C. Suzuki et al.)In the experiment with W injections, W
was successfully injected into the plasma.
The quality of the SOXMOS data are to beinvestigated in the next step.

On the left – one of the successfully
performed TESPEL injections with the Wtracer amount of 0.5E17 particles