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

Bioinertization of NanoLC/MS/MS Systems by Depleting Metal Ions From the Mobile Phases for Phosphoproteomics

We have successfully developed a bioinertized nanoflow liquid chromatography/tandem mass spectrometry (nanoLC/MS/MS) system for the highly sensitive analysis of phosphopeptides by depleting metal ions from the mobile phase. We found that not only direct contact of phosphopeptides with metal components, but also indirect contact with nanoLC pumps through the mobile phase causes significant losses during the recovery of phosphopeptides. Moreover, electrospray ionization was adversely affected by the mobile phase containing multiple metal ions as well as by the sample solvents contaminated with metal ions used in immobilized metal ion affinity chromatography for phosphopeptide enrichment. To solve these problems, metal ions were depleted by inserting an on-line metal ion removal device containing metal-chelating membranes between the gradient mixer and the autosampler. As a result, the peak areas of the identified phosphopeptides increased an average of 9.9-fold overall and 77-fold for multiply phosphorylated peptides with the insertion of the on-line metal ion removal system. This strategy would be applicable to highly sensitive analysis of other phosphorylated biomolecules by microscale-LC/MS/MS

Hydrogen emissions from peripheral plasmas in local island divertor and helical divertor configurations

Superdense core plasmas with a highly peaked electron density profile have been obtained in reduced recycling discharges in the Large Helical Device [ O. Motojima et al., Phys. Plasmas 6, 1843 (1999) ]. The polarization separation spectroscopy technique has been applied to characterize Hα emissions in the peripheral region of superdense core plasmas. Fitting positions of the high intensity Hα line are located just outside of the last closed flux surface in the local island divertor configuration. In the helical divertor configuration, high intensity emissions are observed around the inner and outer X points and along the divertor legs. In both configurations the hydrogen atoms have an inward velocity along the lines of sight

Magnetic Axial Dependency of Hα Emission Location in Peripheral Plasmas of Large Helical Device as Determined by Plasma Polarization Spectroscopy

The behavior of hydrogen neutral particles in and around the ergodic layer of Large Helical Device plasmas has been investigated through Hα emission spectral line profiles using plasma polarization spectroscopy (PPS). The PPS technique enables us to quantitatively evaluate emission locations, atomic temperatures and velocity components along the line-of-sight (LOS) for both inner and outer peripheral regions. The emission locations and the LOS components of atomic velocities are determined by varying the magnetic field axis Rax from 3.60m to 4.00 m, shot by shot. The high intensity region of Hα emissions is localized in the inner ergodic layer for the inward configuration. With an increase in Rax, the high intensity region of Hα emission moves outward

Progress in Impurity-Related Physics Experiments in LHD

A variety of density profiles observed in the Large Helical Device (LHD) have suggested an interesting core impurity transport. The edge impurity transport in the ergodic layer formed by stochastic magnetic field lines with long connection length (10-2000 m) can also exhibit interesting phenomena in the competition of perpendicular and parallel transport. The LHD discharge is highly robust against impurity buildup, and operation is possible essentially up to the global power balance limit because current-driven instability does not principally exist. The LHD plasma has therefore provided information on many interesting physics issues closely related to impurities. Recent results of impurity-related physics experiments in the LHD are briefly reviewed. The specific contents presented here are (1) core impurity behavior with perpendicular transport, (2) edge impurity behavior with parallel transport, (3) high-Z discharges with high ion temperature, (4) impurity pellet injection with improved plasma performance, (5) impurity pellet ablation in the presence of energetic ions with high heat flux and (6) observation of magnetic dipole forbidden transitions for high-Z elements. A result from the Compact Helical System (CHS) is used only in the impurity pellet ablation study, because detailed data have not yet been obtained from the LHD. Finally, the results are summarized and future directions in these topics are noted