Dynamics of magnetic flux jumps in highly dense MgB$_{2}$ samples

Flux jumps in magnetization curves were investigated experimental and theoretically in a polycrystalline MgB$_{2}$ dense sample. We performed magnetization cycles of M-H at different temperatures. Theoretical calculation were performed using an adiabatic critical-state model, that considers the heating effects due to the motion of flux lines, the instability process that originates flux jumps, and the flux redistribution towards a new metastable critical state. The flux jump and temperature dependence in the final state were successfully reproduced from experimental M-H curves. The number of the flux jumps and the jump size increase as the temperature is decreased corroborating the typical flux jump in hard type-II superconductor.