Axial particle trajectory measurements in high-gradient magnetic separation

A technique has been developed for studying the trajectories of paramagnetic particles in a high-gradient magnetic separator. Human red blood cells are used as the paramagnetic particle and their trajectories in relation to a single magnetized stainless-steel wire are imaged. The flow velocity is parallel to the wire and has a value of approximately 50 μm . s^-1. The magnetic field of 1.4 T is applied perpendicular to the wire. A phase modulation technique is used to image the red blood cells with a resolution of less than 0.5 μm. The measured particle trajectories confirm the main features of current theoretical models.