Particle loading and behavior in magnetic traps

Abstract

This thesis focuses on a particle’s magnetic trapping. Being trapped, the particle becomes well-isolated, which makes it suitable for various levitodynamics applications. In experimental part, an efficiency of nebulization as a trap loading technique is investigated. 5 suspensions of SiO2 and polymer particles 1.5–5.2 um in size are sprayed via a jet nebulizer and studied by optical microscopy and high-speed imaging. The nebulization setup performs its function properly but requires further improvements such as increasing the number of produced particles, their visualization and launching speed control, and implementing dehydration procedures. In modeling part, 8 configurations of horizontal magnetic traps are numerically simulated and compared. Geometries built from cone, cylindrical and pencil-shape permanent magnets are consistently investigated to determine their trapping ability. As a result, 6 strong magnetic gaps are revealed. The pencil-shape magnets demonstrate better localization of the trapping area and provide trap depth of 7*10^(-18) J which is large enough to overwhelm the thermal fluctuations. An effect of geometry on the trap’s performance is studied, and an optimal tip radius is 75 μm.