High-Resolution 2D Magnetic Field Measurement of Magnetic Reconnection Using Printed-Circuit Board Coils

Abstract

2D high-resolution magnetic probe arrays for local 2D magnetic field measurements of magnetic reconnection have been developed using advanced printed-circuit board (PCB) technology. Each of these arrays can be equipped with all three components of magnetic pickup coils (5 × 3 mm 2). Each coil is composed of a twosided coil circuit pattern with a line width of 0.05 mm. Based on this new probe technique, we conducted high-resolution and high-accuracy measurements of the current sheet to determine the formation and ejection of plasmoid in a current sheet of two merging tokamak plasmas for the first time.

Design and development of a single-laser 2D Thomson scattering measurement system for TS-6 merging tokamak/magnetic reconnection experiments

“…In the TS-6 case, the ion skin depth of 10 20 m −3 deuterium is about 3 cm. In addition, high-resolution 2D magnetic field measurement in TS-6 [10] detected magnetic islands of several cm and blob-like structures of 2-5 cm in the 𝑟-direction in the current density distribution in the current sheet. Although the designed 𝑧-resolution of 26 mm is not much smaller than the ion skin depth, the 𝑧-resolution has the potential to be upgraded to 13 mm in the future.…”

Recent Progress in High Resolution 2D Imaging Measurements of Reconnection Heating during Merging Plasma Startup in TS-3

“…The apparent reconnection speed E rec is not maximum at this time but the effective resistivity increases to a much higher value than the . Although the radial spatial resolution of the magnetic probes is not sufficient to detect the radial motion of the split current sheet, Akimitsu [48] reported associated island structure formation and ejection-like features, detected by developing new PCB-type radially high-resolution magnetic sensors. Ion temperature rapidly increases during the ejection event and its profile changes to a double peak structure at the end of merging.…”

MHD-FiT: MHD-based dynamic reconstruction of tokamak plasma configuration

“…However, it is noteworthy that the recent EFIT can incorporate plasma rotation [14]. Through a rigorous comparison of our model's results with direct 2D internal magnetic field measurements conducted in TS-6 [15], we have fine-tuned and improved this MHD-based reconstruction method. Additionally, it is worth noting that other equilibrium reconstruction techniques have also incorporated flow [16,17].…”

“…This model leverages the MHD system of equations and utilizes data collected from measurements conducted at the plasma edge. Following the model's introduction, we proceed to assess its capabilities by applying it to the reconstruction of two merging tokamak plasma configurations observed in the University of Tokyo TS-6 experiment [8,15,18]. This experiment serves as an illustrative example of dynamically changing tokamak plasma with active flow, a scenario that does not adhere to typical plasma equilibrium conditions.…”