Confinement Properties of the Levitated Spherator

To eliminate the anomalous loss due to convective cells produced by the existence of the supports in the plasma volume, a levitated superconducting ring was installed in the Princeton spherator. The plasma decay time is increased from 10-15 msec in the supported version to a maximum of 150-220 msec for a helium discharge plasma. At $n_e=2\mathrm{}\times {10}^{11}$ ${\mathrm{cm}}^{-3\mathrm{}}$ and $T_e=1-2\mathrm{}$ eV, this decay time is ½ to ¼ of the calculated density decay time due to the classical diffusion process.