Thermal behavior of flux jumps and influence of pulse-shape on the trapped field during pulsed magnetization of a high-temperature superconductor

The impact of temperature on the pulsed magnetization of a high-temperature superconductor (HTS) has been numerically studied. The resulting trapped field (TF) and its distribution over the HTS have been calculated for samples with random and periodic pinning (a regular triangular lattice). The increasing ambient temperature (within the considered values) has been shown to improve the field-trapping efficiency and lead to the possibility of pumping more flux into the sample with each consecutive pulse (contrary to the low-temperature case). Various pulse shapes produced different results at high temperatures. Trapezoidal pulses showed the highest efficiency owing to the constant-field segments during which the vortices continued to enter the sample. The critical (activation) field of flux jumps has been shown to decrease with the rising temperature. At the highest considered temperature (30 K), the flux jumps occurred during the TF relaxation. To the best of our knowledge, such calculations have been done for the first time.

Automated summary

The study found that increasing ambient temperature can improve the field-trapping efficiency in high-temperature superconductors and allow more flux to be pumped into the sample with each consecutive pulse. Trapezoidal pulses were shown to have the highest efficiency at high temperatures.