Single-phase multipole radiofrequency trap

We present a theoretical basis and simple experimental realization of a multipole radio-frequency trap consisting of four equal cylindrical electrodes, where all of the bars have an in-phase applied voltage. An effective potential, which describes three additional stable quasi-equilibrium points, is obtained, and an electrostatic distribution is calculated using the method of image charges. We construct an experimental setup and localize a group of charged silicate microspheres at normal pressure. The experimental results agree well with the proposed analytical model. A strong dependence on modulation of the radio-frequency field and effective potential is confirmed.