  A trapped magnetic field of greater than 3 T has been achieved in a single
grain GdBa2Cu3O7-{\delta} (GdBaCuO) bulk superconductor of diameter 30 mm by
employing pulsed field magnetisation (PFM). The magnet system is portable and
operates at temperatures between 50 K and 60 K. Flux jump behaviour was
observed consistently during magnetisation when the applied pulsed field, Ba,
exceeded a critical value (e.g. 3.78 T at 60 K). A sharp dBa/dt is essential to
this phenomenon. This flux jump behaviour enables the magnetic flux to
penetrate fully to the centre of the bulk superconductor, resulting in full
magnetization of the sample without requiring an applied field as large as that
predicted by the Bean model. We show that this flux jump behaviour can occur
over a wide range of fields and temperatures, and that it can be exploited in a
practical quasi-permanent magnet system.
