Ring simulation experiment using fine-particle plasmas

We can create a ring structure around a magnetized miniature sphere which is immersed in a fine-particle plasma and rotated around its magnetic dipole axis. Aluminum fine particles generated by a boat method acquire charges by UV light irradiation and are converted to a fine-particle plasma. When the magnetized sphere was rotated in the fine-particle plasma, a ring appeared around the equatorial plane under certain conditions. Unipolar induction can reveal some of ring creation mechanisms of the ring; that is, the rotation frequency matches a theoretical simulating condition, and the location of the ring almost fits with the peak position of potential, which is two to three times the sphere radius. This experiment reveals one of mechanisms why the outer planets such as the Saturn, have rings. It indicates the fact that the unipolar induction plays an important role for the creation of the outer planets in the early stage of the solar system formation