Measurement of toroidal vessel eddy current during plasma disruption on J-TEXT

Liu, L. J.; Yu, Kexun; Zhang, M.; Zhuang, G.; Li, X.; Yuan, Tao; Ren, Bo; Zhao, Qiancheng

doi:10.1063/1.4939035

Cited by 3 publications

(1 citation statement)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Notably, the National Spherical Torus eXperiment (NSTX) employs a circuit model involving matching voltage measurement loops to gauge eddy currents [8]. Moreover, the utilization of a thin printed circuit board array has enabled the measurement of eddy current distribution, and this methodology has been extended to ascertain the poloidal distribution of toroidal eddy currents on the J-TEXT [9].…”

Section: Introductionmentioning

confidence: 99%

Data analysis methods and applications of the eddy current diagnostic system in the Keda Torus eXperiment device

Chen,

Tao,

Yolbarsop

et al. 2024

J. Inst.

View full text Add to dashboard Cite

Since the establishment of the eddy current diagnostic system within the Keda Torus eXperiment (KTX) device, it has unveiled many applications. Recent developments have introduced innovative data analysis techniques alongside compelling experimental results, underscoring the necessity for a comprehensive summary of the system's data analysis approaches and broad applications. Notable features of the system encompass exceptional precision, the ability to encompass shell currents on the entirety of the closed boundary, vector detection of shell currents, and measurement of diverse physical quantities. In terms of data analysis methodologies, meticulous scrutiny of the null field region is conducted, and we reveal a distinctive characteristic within the complex shell current signals, namely the asymmetry of the amplitudes of ±n Fourier coefficients. Moreover, the Hodge decomposition emerges as a pivotal technique, allowing for the distinctive separation of shell currents into three orthogonal components based on their distinct spatial topological properties. With regard to practical applications, an in-depth examination of the vector potential and magnetic helicity flux densities are presented in detail, further highlighting the far-reaching utility of the system's capabilities.

show abstract

Section: Introductionmentioning

confidence: 99%

Data analysis methods and applications of the eddy current diagnostic system in the Keda Torus eXperiment device

Chen,

Tao,

Yolbarsop

et al. 2024

J. Inst.

View full text Add to dashboard Cite

show abstract

The eddy current probe array for Keda Torus eXperiment

et al. 2016

Review of Scientific Instruments

View full text Add to dashboard Cite

In a reversed field pinch device, the conductive shell is placed as close as possible to the plasma so as to balance the plasma during discharge. Plasma instabilities such as the resistive wall mode and certain tearing modes, which restrain the plasma high parameter operation, respond closely with conditions in the wall, in essence the eddy current present. Also, the effect of eddy currents induced by the external coils cannot be ignored when active control is applied to control instabilities. One diagnostic tool, an eddy current probe array, detects the eddy current in the composite shell. Magnetic probes measuring differences between the inner and outer magnetic fields enable estimates of the amplitude and angle of these eddy currents. Along with measurements of currents through the copper bolts connecting the poloidal shield copper shells, we can obtain the eddy currents over the entire shell. Magnetic field and eddy current resolutions approach 2 G and 6 A, respectively. Additionally, the vortex electric field can be obtained by eddy current probes. As the conductivity of the composite shell is high, the eddy current probe array is very sensitive to the electric field and has a resolution of 0.2 mV/cm. In a bench test experiment using a 1/4 vacuum vessel, measurements of the induced eddy currents are compared with simulation results based on a 3D electromagnetic model. The preliminary data of the eddy currents have been detected during discharges in a Keda Torus eXperiment device. The typical value of toroidal and poloidal eddy currents across the magnetic probe coverage rectangular area could reach 3.0 kA and 1.3 kA, respectively.

show abstract