Magnetotail structures in a laboratory magnetosphere

The structure of the magnetotail is investigated in a laboratory simulated magnetosphere. This study builds upon our previous investigation of the mag netotail [Birn et al., 1992], which was explored magnetotail through models and magnetic field measurements in the simulated magnetosphere. In this pa per the magnetic field measurements are complemented by measurements of ion and electron fluxes, plasma temperature and high-resolution optical images . Plasma fluxes are measured with a double-sided Faraday cup that measures the ion and electron fluxes of counterstreaming plasma simultaneously in bo th directions. The overall magnetotail structure is examined with high-reso lution imaging using a gated optical imager and applying digital enhancemen t to the magnetotail region. These images confirm the structures inferred e arlier from the magnetic field measurements, a Y-type magnetic neutral line for northward interplanetary magnetic field, and the expected X-type struc ture for southward IMF.