チテキカンキョウニオケルインタラクションシエンノタメノジッセカイコンテキストニンシキオヨビオウヨウ

We have observed Fe14+ (3s^2 ^1S_0 - 3s3p ^1P_1) and Fe15+ (3s ^2S1/2 - 3p ^2P_[3/2]) emissions from a LHD plasma with a space-resolved extreme-ultraviolet spectrometer. The observed intensity distributions against the viewing chord for the respective emissions are reconstructed to the emission flux distributions in the plasma against the normalized radius of the poloidal cross section with a maximum entropy method. Both of the emissions localize in the periphery region, and the Fe^[14+] emission is located outer side than that of Fe15+. We calculate the charge state distribution of Fe ions against the normalized radius assuming the ionization equilibrium at the electron temperature and density, which are measured by a Thomson scattering method. The calculated result is consistent with the experimental one

小特集：磁場閉じ込め核融合装置における水素原子分子輸送研究の新展開 ３．表面分析と分光計測によって明らかになった 水素原子分子の炉内分布と輸送

プラズマ対向壁の水素吸蔵・放出を評価するための表面・再堆積層・バルクの水素輸送モデルとそのQUESTプラズマ対向壁への適用，およびその結果から構築した炉内粒子循環モデルとQUEST長時間放電に対する解析を紹介する．水素分子の発光スペクトル計測によるQUEST 第一壁近傍やLHD ダイバータ領域における水素分子回転温度計測を紹介する．水素原子の発光スペクトル計測による周辺から炉心までの水素原子輸送ダイナミクスの計測およびそのプラズマ閉じ込めとの関連について紹介する

Analysis of the impurity flow velocity in a wide plasma parameter range for deuterium and hydrogen plasmas in the divertor legs of the stochastic layer in LHD

Impurity flow velocity measurements have been conducted for different magnetic field configurations in a wide plasma parameter range in the divertor leg region of LHD for understanding of the edge impurity transport. In all cases (densities, magnetic configurations, hydrogen (H) & deuterium (D) discharges), flows of several tens of km/s are observed. It is found that the flow in thick stochastic layer is faster than in thin stochastic layer configuration by a factor of 3. Different velocities of different charge states of carbon impurity are observed. The simulation with EMC3-EIRENE code shows similar trend as the experiments, but only qualitatively: faster flow in H compared to D discharges due to the mass effect, faster flow in the case of thick stochastic layer. However, synthetic spectra show discrepancy with experiments in the absolute Doppler shift, where the impurity velocity in the experiments is one order faster compared to the simulations

Spatially resolved measurement of helium atom emission line spectrum in scrape-off layer of Heliotron J by near-infrared Stokes spectropolarimetry

1視線の観測のみで核融合プラズマ中のヘリウム近赤外輝線の発光分布を推定. 京都大学プレスリリース. 2022-09-26.For plasma spectroscopy, Stokes spectropolarimetry is used as a method to spatially invert the viewing-chord-integrated spectrum on the basis of the correspondence between the given magnetic field profile along the viewing chord and the Zeeman effect appearing on the spectrum. Its application to fusion-related toroidal plasmas is, however, limited owing to the low spatial resolution as a result of the difficulty in distinguishing between the Zeeman and Doppler effects. To resolve this issue, we increased the relative magnitude of the Zeeman effect by observing a near-infrared emission line on the basis of the greater wavelength dependence of the Zeeman effect than of the Doppler effect. By utilizing the increased Zeeman effect, we are able to invert the measured spectrum with a high spatial resolution by Monte Carlo particle transport simulation and by reproducing the measured spectra with the semiempirical adjustment of the recycling condition at the first walls. The inversion result revealed that when the momentum exchange collisions of atoms are negligible, the velocity distribution of core-fueling atoms is mainly determined by the initial distribution at the time of recycling. The inversion result was compared with that obtained using a two-point emission model used in previous studies. The latter approximately reflects the parameters of atoms near the emissivity peak

Overview of transport and MHD stability study: focusing on the impact of magnetic field topology in the Large Helical Device

The progress in the understanding of the physics and the concurrent parameter extension in the large helical device since the last IAEA-FEC, in 2012 (Kaneko O et al 2013 Nucl. Fusion 53 095024), is reviewed. Plasma with high ion and electron temperatures (Ti(0) ~ Te(0) ~ 6 keV) with simultaneous ion and electron internal transport barriers is obtained by controlling recycling and heating deposition. A sign flip of the nondiffusive term of impurity/momentum transport (residual stress and convection flow) is observed, which is associated with the formation of a transport barrier. The impact of the topology of three-dimensional magnetic fields (stochastic magnetic fields and magnetic islands) on heat momentum, particle/impurity transport and magnetohydrodynamic stability is also discussed. In the steady state operation, a 48 min discharge with a line-averaged electron density of 1 × 1019 m−3 and with high electron and ion temperatures (Ti(0) ~ Te(0) ~ 2 keV), resulting in 3.36 GJ of input energy, is achieved

STUDY ON K〜0 BIEXCITONS IN CuCl BY NONLINEAR SPECTROSCOPY

報告番号: 乙12430 ; 学位授与年月日: 1995-07-17 ; 学位の種別: 論文博士 ; 学位の種類: 博士(理学) ; 学位記番号: 第12430号 ; 研究科・専攻: 理学系研究