Ion clusters, REB, and current sheath characteristics in focused discharges

Summary form only given. Small fluctuations in current sheath characteristics (peak current density, FWHM of leading sheath, and control parameters of sheath internal structure) are linked to wide fluctuations of ion and ion cluster emission from the pinch. Magnetic probe data were used to correlate variations of current sheath parameters with particle emission intensity, Z/M composition, and particle energy spectrum. The emission of ions and ion clusters at 90° from the axis of a plasma focus discharge was monitored simultaneously with the 0° emission. The cross-sectional structure of the REB (relativistic electron beam) at 180° along the discharge axis was monitored via the deposition of collective-field accelerated ions on a target in the REB direction. Sharp peaks of the D⁺-ion spectrum at 90° were found for E>200 keV/unit charge in all focused discharges. These peaks are due to ion crossing of the azimuthal magnetic field of the pinch region in a predominant ion cluster structure