Magnetic Field Variation Experiment Essay

Sensitivity to the Magnetic Field variation Experiment:-

These first experimental tests cover and explain the influence of the magnetic field flux density, which generated by the permanent Halbach magnet through its applied and removed gradually during the magnetization and demagnetization periods, respectively, within the regenerator and acts on the performance of the AMR.

Whereby, the magnetic field that generate by NdFeB Hallbach magnet strays at its central bore, be proportioned to the distance outside, which the regenerator block is moved away from the center of the Halbach magnet, thus must have an influence on the performance of the regenerator. Therefore, the flux density along the central axis of the Halbach cylinder was measured, used a Hall probe of the Gaussmeter, and the results recorded.

Since, the influence dimensions, length and internal radius, of

span as a function of the distance, where, the regenerator is completely out of the magnetic field.

An additional experiment was performed at a set of magnet, where the magnitude of the applied field was varying. Where, steady state temperatures difference measures in the AMR as a function of the magnetic field.

Whereby, from the geometry of the Gadolinium plates, which gives a rise to a demagnetizing field opposing the applied field, and reducing the internal field of the Gadolinium plates. On the other hand, the thermal conductivity with the geometry of the Gadolinium plates and the active magnetic regenerator geometry both gives a rise and increase the diffusion along the temperature gradient of the plates.

Therefore, any increase in temperature gradient in the plates, due to the gradual application of the magnetic field, will contribute some fraction of loss. Subsequently, will reducing the overall temperature gradient in the plates, and thus decrease the temperature difference (T_span) between the hot and the cold