Validation of fast-ion D-alpha spectrum measurements during EAST neutral-beam heated plasmas

Huang, J.; Heidbrink, W. W.; Hellermann, M. G. von; Stagner, L.; Wu, Cong-Feng; Hou, Ya-Mei; Chang, Jiafeng; Ding, Siye; Chen, Y. J.; Zhu, Y. B.; Jin, Zuanming; Xu, Z.; Gao, Wei; Wang, J. F.; Lyu, Bo; Zang, Qing; Zhong, G. Q.; Hu, Liqun; Wan, Baonian; Team, East

doi:10.1063/1.4960308

Cited by 10 publications

(11 citation statements)

References 12 publications

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“…A successful demonstration of SOS Fast Beam Ion CX modeling for the EAST tokamak was published recently, where SOS is benchmarked against both experimental observation and also against a FIDASIM simulation (cf. [36]). In this paper, we show as an illustration the ITER case for a DNB based FICX simulation which demonstrates that in the best possible location as predicted by a figure of merit study (see Figure 32b) the signal is just barely visible.…”

Section: Slowing-down Beam Ionsmentioning

confidence: 99%

“…The rapid decay of excitation rate coefficient as (~1/n 3 ) where n is the principal quantum number prevents the appearance of plume in all other impurities except of He (see also PEC values for HI, HeII, and CVI in Figure 2h). Finally, the type of synthetic active spectra simulated by SOS is that of fast-ion-CX-spectra, i.e., slowing-down fusion alpha particles [26][27][28][29][30], fast beam ions [31][32][33][34][35][36] or minority ions accelerated by Ion Cyclotron Resonance Heating (ICRH). In all three examples of FICX (Fast-Ion-CXRS), the range of energies of the fast ions exceeds by far the width of the CX emission rate function which typically peaks around 50 keV/amu, and contributes dominantly to measurable signals for relative collision velocities less than 100 keV/amu.…”

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confidence: 99%

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Simulation of Spectra Code (SOS) for ITER Active Beam Spectroscopy

Hellermann

Bock

Marchuk

et al. 2019

Atoms

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The concept and structure of the Simulation of Spectra (SOS) code is described starting with an introduction to the physics background of the project and the development of a simulation tool enabling the modeling of charge-exchange recombination spectroscopy (CXRS) and associated passive background spectra observed in hot fusion plasmas. The generic structure of the code implies its general applicability to any fusion device, the development is indeed based on over two decades of spectroscopic observations and validation of derived plasma data. Four main types of active spectra are addressed in SOS. The first type represents thermal low-Z impurity ions and the associated spectral background. The second type of spectra represent slowing-down high energy ions created from either thermo-nuclear fusion reactions or ions from injected high energy neutral beams. Two other modules are dedicated to CXRS spectra representing bulk plasma ions (H+, D+, or T+) and beam emission spectroscopy (BES) or Motional Stark Effect (MSE) spectrum appearing in the same spectral range. The main part of the paper describes the physics background for the underlying emission processes: active and passive CXRS emission, continuum radiation, edge line emission, halo and plume effect, or finally the charge exchange (CX) cross-section effects on line shapes. The description is summarized by modeling the fast ions emissions, e.g., either of the α particles of the fusion reaction or of the beam ions itself.

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Section: Slowing-down Beam Ionsmentioning

confidence: 99%

mentioning

confidence: 99%

Simulation of Spectra Code (SOS) for ITER Active Beam Spectroscopy

Hellermann

Bock

Marchuk

et al. 2019

Atoms

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“…The overlay of q profiles infered from EFIT constrained by POINT suggests that a stationary and broad current profile was obtained, which was consistent with li change in the H-mode phase. For EP and edge physics, fast-Ion D-Alpha spectrum (FIDA) is developed for fast ion behavior and energetic particle related physics [6]. Particular attention has also been devoted to the edge plasmas diagnostics (e.g.…”

Section: )mentioning

confidence: 99%

Overview of EAST experiments on the development of high-performance steady-state scenario

et al. 2017

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The EAST research program aims to demonstrate steady-state long-pulse advanced high-performance H-mode operations with ITER-like poloidal configuration and RF-dominated heating schemes. Since last IAEA FEC, EAST has been upgraded with all ITER-relevant auxiliary heating and current drive systems, enabling the investigation of plasma profile control by coupling/integration of various combinations. By means of the 4.6 GHz and 2.45 GHz LHCD systems, H-mode can be obtained and maintained at relatively high density, even up to n e ~ 4.5 × 10 19 m-3 , where a current drive effect is still observed. Significant progress has been achieved on EAST, including: i). Demonstration of a steady-state scenario (fully non-inductive with V loop ~ 0.0V at high β P ~ 1.8 and high performance (H 98,y2 > 1.0) in upper single-null (ε ~ 1.6) configuration with the tungsten divertor; ii) Discovery of a stationary ELM-stable H-mode regime with 4.6 GHz LHCD; iii) achievement of ELM suppression in slowly-rotating H-mode plasma with the application of n = 1 and 2 RMPs.

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“…1 In deuterium plasmas, one method of doing so is by fast-ion D-alpha (FIDA) spectroscopy 2,3 which has been implemented in numerous tokamaks and stellarators around the world. [3][4][5][6][7][8][9] FIDA measures the Balmer-alpha radiation from neutralized fast ions following charge-exchange reactions. The neutrals donating the electrons are mostly those injected into the plasma by neutral beam injection (NBI).…”

Section: Introductionmentioning

confidence: 99%

Velocity-space tomography using prior information at MAST

Madsen

Salewski

Huang

et al. 2018

Review of Scientific Instruments

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Velocity-space tomography provides a way of diagnosing fast ions in a fusion plasma by combining measurements from multiple instruments. We use a toroidally viewing and a vertically viewing fastion D-alpha diagnostic installed on the mega-amp spherical tokamak (before the upgrade) to perform velocity-space tomography of the fast-ion distribution function. To make up for the scarce amount of data, prior information is included in the inversions. We impose a non-negativity constraint, suppress the distribution in the velocity-space region associated with null-measurements, and encode the belief that the distribution function does not extend to energies significantly higher than those expected neoclassically. This allows us to study the fast-ion velocity distributions and the derived fast-ion densities before and after a sawtooth crash.

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Validation of fast-ion D-alpha spectrum measurements during EAST neutral-beam heated plasmas

Cited by 10 publications

References 12 publications

Simulation of Spectra Code (SOS) for ITER Active Beam Spectroscopy

Simulation of Spectra Code (SOS) for ITER Active Beam Spectroscopy

Overview of EAST experiments on the development of high-performance steady-state scenario

Velocity-space tomography using prior information at MAST

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