Double Pulsed Field Research Articles

On the extension of the singular point detection technique towards very high pulsed fields

The singular point detection (SPD) technique can greatly reduce difficulties of measurement of anisotropy fields for polycrystalline materials. The SPD technique is a natural application of pulsed magnetic fields. In this paper we discuss the advantages of using a double pulsed magnetic field over a single pulsed field. This is illustrated by computer simulations of the effect of single and double pulsed fields on a well defined sample.

Relaxation measurements of flux pinning by a double pulsed field

We have developed a novel method to measure the relaxation time of flux pinning of type-II superconductors by using a double pulsed field. The magnetic fields are applied to the specimen two times successively. The time between two pulsed fields, t, is adjustable in a time range of milliseconds to any longer time by using twin capacitor banks. The magnetization curve by the first field starts from zero and shows a residual magnetization M 1. In the second field, the magnetization starts from M 2, which is smaller than M 1 due to relaxation. But as the field increases and in high fields, the magnetization curve is identical with the first one and comes back again to the same residual magnetization M 1. We can measure M 1 and M 1 – M 2 precisely and obtain a t-dependence of ( M 1 – M 2) M 1 . This method is applied to study the relaxation measurement of YBCO samples and the result is consistent with the theory.