Flux trapping characteristics of YBCO bulks using pulse magnetization

We have studied magnetization characteristics of an array of high Te superc onductor (HTS) bulk. Experiments using pulsed field magnetization were carr ied out at 77 K. In the experiment, the width of the applied pulse current was varied; i.e., 1) the wave-front length of the pulse magnetization curre nt, and, 2) the wave-tail length of the pulse magnetization current were ch anged independently. We measured the magnetization pattern of single HTS bu lks and that of arrayed HTS bulb. furthermore, several HTS bulks were arran ged ill array and inserted into a pulse magnetization coil wound by copper wire. The measured trapped magnetic flux distribution in this experimental setup was compared with experimental results from "field cooling". The expe rimental result shows that the trapped magnetic flux density is lower in th e pulse magnetization than in the "field cooling", Also, the flux density p attern of pulse magnetization shows a conspicuous sag in the center of the bulk.,As for the effect of the width of the applied pulse wave, the wave-fr ont length affects strongly the trapped magnetic flux density, Meanwhile, t he effect of the wave-tail length was very mild.