Anisotropy and energy spectrum of PF ion-cluster emission

Summary form only given, as follows. The multiple sharp peaks of the D/sup +/-ion energy spectrum below 1 MeV from the Thomson (parabola) spectrometer are typical of the ion emission from plasma focus discharges at 90/spl deg//spl plusmn/45/spl deg/ [electrode axis at 0/spl deg/]. Similar peaks are less frequently observed at 0/spl deg/. This anisotropy is consistent with a greater fluence of ion clusters and superclusters [with very high mass/charge ratio, M/Z/spl ges/10/sup 6/] crossing the pinch magnetic field, as opposed to a lower fluence of single ions crossing the field at 90/spl deg/. Cluster disintegration in flight, after crossing the pinch field, is a clear cause of spectral peaks. The single-ion fluence usually dominates over the cluster population fluence at 0/spl deg/. The relative weight of different cluster-disintegration processes, as collisions with the background gas or with solid structures on the cluster trajectory is determined by other spectral characteristics of single ions and of low magic-number clusters. These are, typically, the origin of all parabolas (of different ion species) from a constant-velocity-line or, alternatively, from a constant-energy-line, on a Thomson spectrometer target exposed to a single discharge.