Numerical Modelling and Analysis of Flux Jumps in MgB2 Bulks: How to Improve the Performance of MgB2 Bulk Magnets
Résumé
Due to their very low density, MgB2 bulk samples should be considered for the generation of strong magnetic flux densities in electrical engineering applications [1, 2]. However, over the past few years many flux jumps have been observed on various MgB2 samples in both field cooling and pulsed field magnetization processes [3]. In large samples prepared by spark plasma sintering process [4] or Reactive Liquid Mg Infiltration (Mg-RLI), even at low sweep rates, repetitive flux jumps may appear as shown in Fig. 1 with an MgB2 pellet (Mg-RLI, Ø 50 mm diameter and height h ≈ 20 mm). In this paper, we will discuss the benefits of using numerical tools to improve the trapped magnetic field produced by MgB2 samples, providing operation processes, technical solutions and/or material characteristics that can effectively suppress flux jumps during the magnetization processes.
References:
1. M. R. Koblischka et al., IEEE Trans. Magn. 50, 9000504 (2014).
2. K. Berger et al., IEEE Trans. Appl. Supercond. 26, 6801005 (2016).
3. H. Fujishiro et al., Phys. Procedia 58, 286–289 (2014).
4. J. G. Noudem et al., Materials Today-Proceedings, 3 (2), 545–549 (2016).