| 초록 |
The chemical analysis of fine particles is crucial to researching on the mechanism of particle nucleation and growth at the atmosphere. Therefore, the particles only should be sampled from the atmosphere into a vacuum chamber without air. However a large portion of the particles is lost during removing the air in the sampling process. Sampling a sufficient number of particles is important to ensure adequate signal-to-noise. A way to reduce the particle loss is suggested using alternating 2-dimensional quadrupole electric field in the present study. An inhomogeneous hyperbolic electric field is made between the 2-dimensional quadrupole electrodes which an ac voltage is applied to. Charged particles may be focused into a narrow axis region by an inhomogeneous electrodynamic force in the quadrupole electric field. The behavior of the charged particles in the quadrupole electric field is influenced by the aerodynamic drag force and electrodynamic force. Particle trajectories and focusing rates are studied in terms of two dimensionless parameters which are functions of particle size, operating pressure, and the amplitude and frequency of applied ac voltage. |
