Development of an integrated energetic neutral particle measurement system on experimental advanced full superconducting tokamak

Zhu, Y. B.; Zhang, J. Z.; Qi, Ming; Xia, Shijun; Liu, D.; Heidbrink, W. W.; Wan, Baonian; Li, J. G.

doi:10.1063/1.4886431

Cited by 10 publications

(5 citation statements)

References 11 publications

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“…Two horizontal solid state neutral particle analyzers (ssNPA) along toroidal direction have been equipped on EAST [31,32] as shown in figure 1(a) at z ≈ −15 cm below the equatorial plane. Each detector of the horizonal ssNPA is equipped with the tungsten (W) foil of thickness 100nm that can provide the detection threshold for deuterium ions temperature around 22 keV.…”

Section: Apparatus and Experimental Phenomenamentioning

confidence: 99%

Observation of electromagnetic GAMs excited by NBI in EAST

Zhang

Zhou

et al. 2018

Nucl. Fusion

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Energetic ions induced electromagnetic geodesic acoustic modes (EGAMs) instabilities during the modulated injection of neutral beams of NBI 1L and NBI 1R have been observed in EAST. The EGAMs coexist with the lower frequency modes (LFMs) instabilities: the frequencies are constant in the radial direction for EGAMs in the range of 0.5 < ρ 0.8, while LFMs are located in the range 0.1 < ρ 0.3. The density perturbation for EGAM is nearly up-down anti-symmetric, while the magnetic perturbation for EGAM that is standing wave with a principal m = 2 lobe, and an m = 4 side-lobe is commonly observed for κ > 1. EGAMs have strong correlations with the injections of energetic ions, and the toroidal rotation velocity v φ is partially suppressed by the mode excitations, while the magnetic islands of LFM instabilities can form the configuration of 'hollow' structure for v φ . The most pronounced feature of the EGAMs is that the magnetic fluctuations are not antisymmetric in the poloidal angle θ, and they can be expressed as δB θ ∝ sin 2(θ − θ 0 ) + εf (θ, θ 0 ), and the θ 0 is a function of the pitch angle and energy of energetic ion. The new structure of asymmetry for EGAM has been observed when |θ 0 | > π/8, where the radial structure extends outward in bottom section, and also exhibits non-uniformity in the toroidal direction, and one possible explanation for the asymmetry is that EGAM are modulated by LSW instabilities with frequency 0 < f x < 4 kHz.

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Section: Apparatus and Experimental Phenomenamentioning

confidence: 99%

Observation of electromagnetic GAMs excited by NBI in EAST

Zhang

Zhou

et al. 2018

Nucl. Fusion

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“…It does not result in any measurable magnetic perturbation on Mirnov signals in (c). ssNPA measures the lost fast neutral particles and also reflects the presence of energetic ions in plasma to some extend [46]. The frequency spectrum of ssNPA fluctuations shows continuing chirping-down evolutions round f = 21 kHz which is the precession frequency of ~22 keV energetic ions in current experimental condition.…”

Section: Effects Of Energetic Ions On Mhd Modesmentioning

confidence: 86%

The dynamics of a neoclassical tearing mode (NTM) influenced by energetic ions on EAST

Li¹,

Igochine²,

Xu³

et al. 2016

Plasma Phys. Control. Fusion

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In the 2014 year's campaign of Experimental Advanced Superconducting Tokamak (EAST), a series of Magnetohydrodynamics (MHD) instabilities were observed as the launching of Neutral Beam Injection (NBI), the most interesting one of which is the neoclassical tearing mode (NTM). Evidence clearly shows that a kink mode present after a strong sawtooth-like (ST-like) crash leaves a perturbation near the location of the magnetic island, providing the initial seed. The interaction of energetic ions makes the magnetic island oscillate both in island width and in rotation frequency. Analysis indicates that the bulk plasma still 2 dominates the dynamics of NTM, and the orbit excursion of energetic ions induces a polarization current and modifies the width and rotation frequency of the neoclassical magnetic island.

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“…These can produce a non-Maxwellian aniso- tropic high energetic ion population, which can contribute to plasma heating and current drive, and also can cause damage to the first wall. Several other new complementing techniques are also under development to study the fast-ion behavior, e.g., neutral particle analyzers (NPAs), 9 fast-ion loss detectors (FILDs), gamma camera, and neutron camera.…”

Section: Introductionmentioning

confidence: 99%

Fast-ion Dα spectrum diagnostic in the EAST

Hou

Huang

et al. 2016

Review of Scientific Instruments

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In toroidal magnetic fusion devices, fast-ion D-alpha diagnostic (FIDA) is a powerful method to study the fast-ion feature. The fast-ion characteristics can be inferred from the Doppler shifted spectrum of D light according to charge exchange recombination process between fast ions and probe beam. Since conceptual design presented in the last HTPD conference, significant progress has been made to apply FIDA systems on the Experimental Advanced Superconducting Tokamak (EAST). Both co-current and counter-current neutral beam injectors are available, and each can deliver 2-4 MW beam power with 50-80 keV beam energy. Presently, two sets of high throughput spectrometer systems have been installed on EAST, allowing to capture passing and trapped fast-ion characteristics simultaneously, using Kaiser HoloSpec transmission grating spectrometer and Bunkoukeiki FLP-200 volume phase holographic spectrometer coupled with Princeton Instruments ProEM 1024B eXcelon and Andor DU-888 iXon3 1024 CCD camera, respectively. This paper will present the details of the hardware descriptions and experimental spectrum.

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Development of an integrated energetic neutral particle measurement system on experimental advanced full superconducting tokamak

Cited by 10 publications

References 11 publications

Observation of electromagnetic GAMs excited by NBI in EAST

Observation of electromagnetic GAMs excited by NBI in EAST

The dynamics of a neoclassical tearing mode (NTM) influenced by energetic ions on EAST

Fast-ion Dα spectrum diagnostic in the EAST

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