Parametric stabilization and cooling of microparticles in a quadrupole ion trap

We discuss the current progress on study of cooling of levitated microparticles under high vacuum conditions (6 x 10(-7) Torr). Particle levitation as well as feedback cooling are done using an electrical AC trap (quadrupole ion trap). It is shown that we can cool particle motion in all three degrees of freedom to 50-100K and increase their trapping time from a few hours without feedback to times exceeding weeks when the particles are cooled. The cooling is achieved by FM modulation of the AC trap frequency, and data on its dependence on gain settings is presented.