Electromagnetic behaviour of bulk MgB2 determined by numerical modelling using regional supercurrent properties

A reconstructed three-dimensional HTS bulk electromagnetic model considering J c spatial inhomogeneity and its implementation in a bulks’ combination system

“…Some intrinsic properties of superconductors such as inhomogeneity and anisotropy of bulk are gradually considered in some models. Ozturk et al [26] simulated the trapped magnetic field using the radius-dependent critical current density J c (B, r) as input data for an MgB 2 superconductor rather than using a constant critical current density. The authors [27] proposed a function of two variables J c (x, y) to describe the J c nonuniformity distribution in the popular YBaCuO bulk.…”

IR laser line scanning treatments to improve levitation forces in MgTi0.06B2 bulk materials

“…MgTi0.06B2 bulk samples, in which the external part is doped with Ag (0, 3 and 6 wt%), were obtained using the fabrication processes presented in a previous study [28]. A pellet of MgTi0.06B2 with 13 mm in diameter and 7 mm in thickness was pressed under a uniaxial pressure of approximately 250 MPa and the pressed pellet was placed at the centre of a mould with 18.5 mm in diameter.…”

“…The trapped field initially increases with the sample radius [27], and eventually reaches a saturation value above certain diameters. Previously reported numerical and experimental studies of our research group, have demonstrated that the number of cracks and voids increases with increasing sample radius, reducing the current flow through the matrix and therefore Jc [28,29]. In these experimental studies [29], MgTi0.06B2 bulk samples were fabricated by adding Ag nanoparticles locally in the edge region of the sample, with the objective of reducing the number of cracks and voids, and yielded the improvement of Jc values and magnetic levitation forces.…”

Analysis of critical current inhomogeneity in r–z plane of GdBCO superconducting bulk and simulation of flux jumps during pulsed field magnetization

“…Some researchers introduced a piecewise constant J c [25] and a cosine function [26,27] to describe the circumferential inhomogeneous J c properties in FC and PFM simulations. Ozturk and Dancer adopted a radius-dependent J c (B, r) as the input variable for the simulation of MgB 2 [28]. Recently, Zheng et al [29] and Cheng et al [30] independently proposed 3D spatial J c distribution models based on parameter fitting and Gaussian normal distribution methods.…”