Determination of Iron Density at the Plasma Center Using Radial Profile of FeKα Lines in LHD

Muto, S.; Morita, S.

doi:10.1585/pfr.3.s1086

Cited by 7 publications

(5 citation statements)

References 11 publications

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“…The energy resolution of E/ΔE is estimated from the x-ray emissivity in LHD. The emissivity integrated between 3.0 and 10 keV is 1.5 × 10 18 photons/m 3 /s in the case of typical NBI plasmas of LHD [3]. This fact means in the case of the configuration that the incident intensity is 2.5 × 10 6 photons/s/pixel.…”

Section: Design Of Assembly Of Pin-hole Camera In Lhdmentioning

confidence: 89%

“…The x-ray spectroscopy for plasma physics is important to study the behaviors of electrons and impurities such as argon and transition metals [1,2]. Recently, the local emissivities of impurity line and the bremssstrahlung emitted from electrons have been estimated from the timeresolved profiles of x-ray spectra [3]. Especially, it is confirmed that the energy and spatial distributions of the electrons is non-thermal in ECH plasma [4].…”

Section: Introductionmentioning

confidence: 99%

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Design for X-Ray Imaging Spectroscopy in Large Helical Device

Muto

2013

Plasma and Fusion Research

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An assembly of pin-hole camera has been designed for x-ray imaging spectroscopy in Large Helical Device (LHD). In the design the camera basically consists of a 2-D-pixel-array detector, a metallic filter, and a pin hole. The detector measures gray scale images through the filter, while the thickness of the filter changes shot by shot. The gray scale images are mathematically transformed to a color spectral image by means of Mellin transform. The available spectral range is depending on the material of the filter. The spectral energy resolution is also depending on the material of the filter and the intensity of incident x-ray. In the case of the filter made of aluminum, the spectral range is theoretically predicted to be from 3.0 keV to 30 keV. It is also theoretically expected in the case of typical LHD plasmas that 50 flames of color spectral 32 × 32-pixel-image is obtained per second with a spectral resolution of E/ΔE = 4.3 at a photon energy of E = 5.0 keV.

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Section: Design Of Assembly Of Pin-hole Camera In Lhdmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Design for X-Ray Imaging Spectroscopy in Large Helical Device

Muto

2013

Plasma and Fusion Research

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“…Finally, it should be noted that the edge plasma diagnostics using polarization spectroscopy [23] and magnetic dipole forbidden transition [24,25] have been newly tried in the visible range. The charge state distribution of iron has been studied using Kα X-ray lines for core impurity transport [26,27] . Spectroscopy on ablation cloud of the impurity pellet has also been started as part of the particle diffusion study [28] .…”

Section: Discussionmentioning

confidence: 99%

Edge and Core Impurity Transport Study with Spectroscopic Instruments in LHD

Morita

Goto

Kobayashi

et al. 2009

Plasma Sci. Technol.

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Impurity transport was investigated at both edge and core regions in large helical device (LHD) with developed spectroscopic instruments which can measure one-and two-dimensional distributions of impurities. The edge impurity behavior was studied recently using four carbon resonant transitions in different ionization stages of CIII (977 Å), CIV (1548 Å), CV (40.3 Å) and CVI (33.7 Å). When the line-averaged electron density, ne, is increased from 1 to 6 × 10 13 cm −3 , the ratio of (CIII+CIV)/ne increases while the ratio of (CV+CVI)/ne decreases. Here, CIII+CIV (CV+CVI) expresses the sum of CIII (CV) and CIV (CVI) intensities. The CIII+CIV indicates the carbon influx and the CV+CVI indicates the emissions through the transport in the ergodic layer. The result thus gives experimental evidence on the impurity screening by the ergodic layer in LHD, which is also supported by a three-dimensional edge particle simulation. The core impurity behavior is also studied in high-density discharges (ne ≤ 1 × 10 15 cm −3 ) with multi H2-pellets injection. It is found that the ratio of V /D (V : convection velocity, D: diffusion coefficient) decreases after pellet injection and Z eff profile shows a flat one at values of 1.1∼1.2. These results confirm no impurity accumulation occurs in high-density discharges. As a result, the iron density, nFe, is analyzed to be 6 × 10 −7 (= nFe/ne) of which the amount can be negligible as radiation source even in such high-density discharges. One-and two-dimensional impurity distributions from space-resolved VUV and EUV spectrometers newly developed for further impurity transport study are also presented with their preliminary results.

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“…Iron most likely needs to be in the plasma state. Then it contains considerably more free electrons than in a liquid state [38].…”

Section: Moon's Internal Heatmentioning

confidence: 99%

Gas Pressure Triggered by Helium as Driving Force in Tectonic Movements

Hänninen¹

2019

eer

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The helium bulge in the thermosphere above the winter pole demonstrates that solar wind strips helium from the thermosphere into space. The existence of the bulge shows that helium flows from the interior of the earth replenish what the solar winds strip away. The calculations of Lord Kelvin showed that the primordial heat would have been exhausted within the first 98 million years of the earth's existence. There may be as much as 45 times more heat and helium generated by the radioactive decay of uranium and thorium in the earth's core than has been previously estimated. A plausible mechanism to trigger tectonic movements is the pressure exerted by helium as it ascends from the earth's core. In the mantle, helium pierces the rock and strips its bound water and the resulting steam intensifies the gas flow. Mathematically, the vertical thrust of gases per square meter in the asthenosphere more than equals the weight of a 100 km high and 1 m 2 wide column of stone. Basalt in the oceanic crust diverts a major part of the upwelling flow of gas below the sea areas to horizontally push the continental plates. Only a minor part of the flow is liberated through black smokers. The combined effect of vertical lift and horizontal thrust of the gases then moves the tectonic plates. If a tectonic plate moves on one of the poles, it will accumulate ice, which causes the sea level to drop dramatically. This occurred when the movement of Antarctica on the South Pole lowered the sea level by 83 m from the elevation which prevailed in the early Cretaceous period 124 million years ago. Variations of the helium flow may be used as an indicator in assessing the possibility of volcanic eruptions and earthquakes.

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Determination of Iron Density at the Plasma Center Using Radial Profile of FeKα Lines in LHD

Cited by 7 publications

References 11 publications

Design for X-Ray Imaging Spectroscopy in Large Helical Device

Design for X-Ray Imaging Spectroscopy in Large Helical Device

Edge and Core Impurity Transport Study with Spectroscopic Instruments in LHD

Gas Pressure Triggered by Helium as Driving Force in Tectonic Movements

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