AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Linear Electrodynamic Quadrupole Trap for Single Particle Studies
MATTHEW HART, Erin M. Durke, Jason Edmonds, Jay Eversole, Naval Research Laboratory
Abstract Number: 259 Working Group: Aerosol Physics
Abstract Advantages of using a linear electrodynamic quadrupole trap (LEQ) include the relative ease, or increased efficiency of particle capture and control. The stability region of the LEQ is along the symmetry axis defined within four parallel, equally spaced rods, and can be many centimeters in length. Within this region one, or multiple, charged, micron-sized particles can be captured and confined at ambient atmospheric pressures. Although similar to the established mechanism used for the quadrupole mass filter in ion mass spectroscopy (IMS), the lack of vacuum in the LEQ creates a damping effect on the particles which broadens the conditions of stability with respect to an IMS quadrupole mass filter. We have trapped particles ranging in size from 0.5 um to 10 um with only small adjustments in the operating parameters such as LEQ frequency. Trapped particles can be held stationary or controllably conveyed along the axis by using a combination of airflow along the length of the device and properly placed electric potentials. Multiple optical measurements can be made along the length of the LEQ. We report the modeling of particle trajectories, stability limits and trapping within a LEQ together with experimental data obtained from liquid and solid particles for model validation. Recent experimental results pertaining to evaporation rates and light scattering phenomena will be presented.