The conceptual design of interferometer/polarimeter system on HL-2M

Zhang, Yan; Wang, H. X.; Li, Y. G.; Li, Y.; Chen, W. J.; Jiang, Yi; Deng, Z.C.

doi:10.1063/1.4959911

Cited by 8 publications

(5 citation statements)

References 11 publications

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“…a 11 cm gap for 0.5 MW coupled power), and assisted in triggering and sustaining the H-mode. Some advanced diagnostic systems have been developed and upgraded, including a multi-channel HCOOH laser interferometer and polarimeter [3,4] for density and Faraday rotation measurement, a 384-channel electron cyclotron emission imaging (ECEI) system for two-dimensional (2D) electron temperature fluctuation measurement [5], a multi-channel correlation Doppler backscattering reflectometer (DBS) for poloidal rotation and turbulence measurement [6], a Doppler coherence imaging system for toroidal rotation measurement, a high-frequency magnetic probe array for the detection of high mode-number (m/n = 20/30) MHD instabilities [7] and a wideangle infrared (IR) periscope diagnostic for the observation of plasma wall interaction in the main chamber. A variety of fuelling techniques, such as massive gas injection (MGI) and gas mixture supersonic molecular beam injection (SMBI), have been developed or improved.…”

Section: Introductionmentioning

confidence: 99%

Overview of recent HL-2A experiments

Duan

Liu

et al. 2017

Nucl. Fusion

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For the firsttime supersonic molecular beam injection (SMBI) and cluster jet injection (CJI) were applied to mitigate edge-localized modes (ELMs) in HL-2A successfully. The ELM frequency increased by a factor of 2-3 and the heat flux on the divertor target plates decreased by 50% on average after SMBI or CJI. Energetic particle induced modes were observed in different frequency ranges with high-power electron cyclotron resonance heating (ECRH). The high frequency (200-350kHz) of the modes with a relatively small amplitude was close to the gap frequency of the toroidicity-induced Alfven eigenmode. The coexistent multi-mode magnetic structures in the high temperature and low-collision plasma could affect the plasma transport dramatically. Long-lived saturated ideal magnetohydrodynamic instabilities during strong neutral beam injection heating could be suppressed by high-power ECRH. The absolute rate of nonlinear energy transfer between turbulence and zonal flows was measured and the secondary mode competition between low-frequency (LF) zonal flows (ZFs) and geodesic acoustic modes (GAMs) was identified, which demonstrated that ZFs played an important role in the L-H transition. The spontaneously generated E × Bshear flow was identified to be responsible for the generation of a large-scale coherent structure (LSCS), which provided unambiguous experimental evidence for the LSCS generation mechanism. New meso-scale electric potential fluctuations (MSEFs) at frequency f ∼ 10.5 kHz with two components of n = 0 and m/n = 6/2were also identified in the edge plasmas for the first time. The MSEFs coexisted and interacted with magnetic islandsof m/n = 6/2, turbulence and LF ZFs.

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Section: Introductionmentioning

confidence: 99%

Overview of recent HL-2A experiments

Duan

Liu

et al. 2017

Nucl. Fusion

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“…We use a matrix labeled with spatiotemporal distribution profiles that involve coupling VV and divertor geometric models r(x, y, z)with current density profiles j( r , , z, t). [30][31][32][33][34] During the VDE disruption, the plasma current quenching usually lasts for several to tens of milliseconds' decay, with plasma current spatiotemporal distribution changing rapidly. We introduce the current density distribution vector j imposed on the plasma region ds by combining material properties and element selection boundary conditions.…”

Section: Current Profile In Vdementioning

confidence: 99%

Prediction of Electromagnetic Loads for HL-2M Plasma Facing Components in Vertical Displacement Event

Chen

Liu

et al. 2022

Preprint

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Three-dimension (3-D) geometry models are established for HL-2M tokamak Plasma-Facing Components (PFCs), including Vacuum Vessel (VV) and divertor by ANSYS in this study. We predict Electromagnetic (EM) loads during an upwards Vertical Displacement Event (VDE) disruption by introducing plasma & magnetic field coils currents models. Eddy currents are induced due to the decay of plasma current and then flow into the PFCs components. The interaction between eddy currents and magnetic fields generates enormous EM forces and torques. During the VDE disruption, the halo currents are also born due to plasma currents moving to VV and divertor accompanied with dynamic evolution. Halo currents flow into VV and divertor inside components from the inner &outer target plate, the demo plate, and the cassette box. We found that the EM loads are most substantial on the radial& poloidal EM forces by introducing discretized spatiotemporal current profiles calculated from the DINA code. Inward & upward forces are the dominant factor in the VV and divertor. It may provide helpful experiences in designing China Fusion Engineering Test Reactor (CFETR).

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“…The phase information is directly related to electron density and Faraday rotation in the plasmas. The difference of refractive index for the (R-and L-) waves in the magnetized plasma leads to a relative phase shift approximately: [12,17,[21][22][23][24]]…”

Section: Description Of Two-laser Pier Techniquementioning

confidence: 99%

Demonstration of two-laserPolarimeter-Interferometer(PIer) scheme for simultaneous measurements of Faraday rotation angle and electron density on HL-2A

Zhang

Deng

et al. 2017

J. Inst.

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A novel two-laser Polarimeter-Interferometer (PIer) diagnostic scheme, in which Faraday rotation angle (αF) and electron density (ne) can be simultaneously measured by taking advantage of two lasers and two detectors for each channel, has been successfully demonstrated on HL-2A tokamak through upgrading one channel of existing monofunctional Faraday-effect polarimeter. In comparison with the conventional three-laser PIer diagnostic, two-laser PIer generates only one intermediate frequency (IF), avoiding the overlap of IF frequency bands, so as to increase the time resolution and decrease the phase noise of system. The single channel two-laser PIer was firstly put into operation in 2016 HL-2A experimental campaign, and both Faraday rotation angle and electron density phase have been measured with a fast time resolution of 1.0 μs and a phase resolution of 0.1̂ and 1.0̂, respectively. This work is valuable for next step far-infrared (FIR) laser PIer construction on HL-2M tokamak, as well as the future International Thermonuclear Experimental Reactor (ITER).

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The conceptual design of interferometer/polarimeter system on HL-2M

Cited by 8 publications

References 11 publications

Overview of recent HL-2A experiments

Overview of recent HL-2A experiments

Prediction of Electromagnetic Loads for HL-2M Plasma Facing Components in Vertical Displacement Event

Demonstration of two-laserPolarimeter-Interferometer(PIer) scheme for simultaneous measurements of Faraday rotation angle and electron density on HL-2A

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