Neutron irradiation on MgB2

We measured the upper critical field Hc2 and the critical current density Jc on neutron-irradiated MgB2 samples and studied the effects of damaging on pinning mechanisms. We observed a strong enhancement of the upper critical field and great improvement of the critical current magnetic field dependence in an intermediate range of fluence. We demonstrated that the critical current increase is not only due to the Hc2 improvement but the irradiation substantially changes the pinning force improving the critical current density at high magnetic field.