(MAP) Session Report
Date: Apr. 26, 2024
Time: 10:22 – 16:44
Shot#: 190360 – #190475 (116 shots)
Prior wall conditioning: None
Divertor pump: ON
Gas puff: H2, Ne

Apr. 26, 2024 (R.T. Ishikawa)

NBI#(1, 2, 3, 4, 5) = gas(H, H, H, H, H)=P(4.3, 4.0, 4.3, 3.9, 5.5) MWECH(77GHz) = ant(1.5-Uo, 5.5-U, 2-OUR)=P(-, 0.698, 0.380) MW
ECH(154GHz) = ant(2-OLL, 2-OUL, 2-OLR)=P(0.705, 0.889, 0.982) MWICH(3.5U, 3.5L, 4.5U, 4.5L) = P(-, -, -, -) MWTopics
1. Simultaneous multi-wavelength spectroscopies for validation on atomic data and spectroscopic modelings forhighly charged ions (I. Murakami)
2. Solid hydrogen pellet injection to plasmas in extended operational regime (H. Yamada)3. Investigation of edge impurity transport in impurity-seeded detachment combined with high beta plasma (E.
Wang)

MAP: “Simultaneous multi-wavelength spectroscopies for validation on atomic data andspectroscopic modellings for highly-charged ions”
I. Murakami, D. Kato, H. A. Sakaue, T. Oishi, T. Kawate, Y. Kawamoto, M. Goto
• Conditions: #190360-#190380. NBI #1-#5. ECH. H2gas. (Rax, Polarity, Bt, γ, Bq) = (3.6 m, CW, 2.75 T, 1.2538,100.0%)• Objectives: Spectroscopic model (Collisionalradiative (CR) model) of tungsten ions is to bevalidated with the measured spectra using LHD,
especially for low charged ions.
• Experiments: A tungsten impurity pellet wasinjected at 4.1s. NBI #1-3 were injected at 3.3-5.3s
and NBI#4-5 were injected at 5.3-7.3s. EUV spectraat 3.0-10nm and 16-38nm were measured. Ion
temperature was measured with modulating NBI #4.
• Results: Strong radiation power of accumulated
tungsten at core causes temperature hole. Ion
temperature distribution also shows hole structure.
Quasi-continuum spectra produced by low charged
tungsten ions were measured at 16-38 nm. Veryweak profile was found at around 30nm, which is
weaker than expected from the CR model.

Solid hydrogen pellet injection to plasmas
in extended operational regime
Background and objective

X.Dai1, H.Yamada1, R.Sakamoto2, N. Tamura1,2

1UTokyo, 2NIFS

l This study aims at the comprehensive characterization of pellet penetration and deposited particles towards
clarification of particle transport and optimization of a fueling scheme/scenario in a fusion reactor.
l While the Neutral Gas Shielding (NGS) model gives rough prediction of the penetration depth of a pellet, it
misses important physical mechanisms such as shielding by plasmoid ablated from a pellet, drift motion, etc..
l Compilation of dataset of pellet injection/ablation with accumulation of missing data. Particularly, data ondifferent NBI heating.

Experimental Condition ■Rax=3.6m

n NBI plasmas (#190384-190402) B=2.75T
n NBI plasmas (#190403-190257) B=2T
n Propellant gas: Ne, He

Resultsn Data on low-speed pellet of different radius with Ne gas
as the propellant has been extended:
508m/s < Vp < 1339m/s
n Missing regime of magnetic field in the dataset has
been filled at 2T
Exp. 2024/4/26

3

Solid hydrogen pellet injection to plasmas
in extended operational regime 2Correlation between leading parameters
Results 2● existing dataset ● newly obtained data (tang. NBIs)
n Data on perpendicular NBIs only has been appended● existing dataset ● newly obtained data (perp. NBIs)
Scopen The existing dataset has provided the scaling
expression of penetration depth l in NBI heatedplasms:(nf.ion : fast ion density)

which suggests significant contribution of magnetic field
and fast ion which are not included in NGS model.
n Extended dataset will improve the quality of theassessment of contributions from B and nf.ion.
n Newly obtained data on perpendicular NBIs(40-60kev)
only will be used for proceeding the comparison to dataon tangential NBIs(180kev) to validate fast ion effects.
n Further study: calculate the velocity distribution functionof fast ion using FIT3D code and aligning with HPI2code.

4Investigation of edge impurity transport in impurity seeded detachment combined with high beta
plasma(E. Wang)
Experimental conditions:(Rax, Polarity, Bt, γ, Bq) = (3.6 m, CW, 1.375 T& 1 T, 1.2538, 100.0%)(# 190459 - #190474)
Objective:
To investigate edge impurity transport properties and its relation with edge magnetic topology in neonseeded detachment scenarios with high beta.
Results:• Neon-seeded detachment has beenachieved in high beta plasma.
• Divertor Langmuir probe measurementsshows more symmetry in deep
detachment in some shots.
• The edge impurity distribution from
VUV/EUV spectrometers will beanalyzed with simulation EMC3-EIRENE.
• Edge magnetic topology will becalculated by HINT.

#190473