Numerical Simulation of Trapped Field and Temperature Rise in $\hbox {MgB}_{2}$ Bulks Magnetized by Pulsed Field

Pulsed field magnetization (PFM) was performed for the MgB₂ bulk 30 mm in diameter and the applied pulsed-field dependence of the trapped field B_T^C, temperature rise ΔT and time dependence of the local field B_L^C(t) were measured on the bulk. B_T^C = 0.71 T was achieved at 14 K after applying the pulsed field of B_ex = 1.55 T, where ΔT of about 10 K was observed. Numerical simulation of PFM was also performed and B_T^C, ΔT and B_L^C(t) were simulated. The results of the simulation reproduced the experimental ones qualitatively. The flux dynamics and the heat generation in the MgB₂ bulk during PFM were in clear contrast with those in REBaCuO bulks because of a small specific heat, large thermal conductivity, and narrow temperature margin against the transition temperature T_c.