INVESTIGATION AND ANALYSIS OF THE DYNAMIC TRAJECTORIES SEEN WITHIN A 7 ELECTRODE ELECTROSTATIC LEVITATOR

Using novel digitally controlled power supplies a detailed study has b een made of complex closed loop trajectories in a horizontal plane exh ibited by particles under levitation in a seven-electrode quadrupole l evitator. Further insight into the dynamics of such trajectories has b een gained by analysing the output of a time-sliced finite element mod el using a Fast Fourier transform program. Observation of the trajecto ries has led to the discovery of a simple relationship between the rat io of the quadrupole and boxer electrode frequencies and standard Liss ajou figures. It has also been seen that changing the phase between th e two applied a.c. signals or altering the magnitude of the boxer elec trode voltage has the effect of topologically distorting the trajector y. The inter-relationship between the observed trajectories and the el ectrical conditions was valid for different quadrupole geometries and for particles with different dielectric properties. Hence with these r esults general predictions can be made of a particle's trajectory and period, with complex electrode geometries. All the experimental observ ations are undertaken under standard atmospheric conditions where visc ous air damping is a significant parameter.