 In the field cooled (FC) regime, the ideally hard superconductor screens perfectly the change of the magnetic field rather than the magnetic field itself.Its magnetization behavior can be described by Bean's critical state model.The ideally hard superconductor is a good approximation for the melt-textured high temperature superconductors (HTSC) used in large scale HTSC applications such as flywheels, HTSC bearings, HTSC motors, etc.