Experiments in pulsed hollow cathode discharges demonstrate that long-lived species, with lifetime of the order of seconds, play a significant role in the formation of the discharge in nitrogen. Detailed studies show that the effect is strongest in the hollow cathode region. Similar effects are not observed in hydrogen. A simplified model of the destruction of the N2(A3Σ+u) state has been adopted to study the relevance of this level. The possible roles of the metastables in the formation of pulsed hollow cathode discharges are discussed.

The ionization process in the prebreakdown phase of a transient hollow cathode discharge (THCD) is investigated. The discharge is operated in H2 and N2 at pressures between 30 and 750 mTorr with applied voltages up to 30 kV. A capacitive probe array is used to measure the spatial and temporal evolution of plasma formation in the interelectrode spacing. The results obtained are consistent with the formation of a moving virtual anode. The growth and evolution of the virtual anode are closely linked to the formation of electron beams emitted from the hollow cathode region before and at the time of electric breakdown.

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A high diffraction efficiency and wide exposure latitude holographic processing method, capable of producing archival quality holograms is presented. It consists of a solution stage physical development on CPA-1, followed by a fixing stage. Holograms thus obtained have a wide exposure latitude and high diffraction efficiency. The method has been tried on 875-HD and 10E75-HD Agfa-Gevaert emulsions.

A time- and space-resolved technique to record the evolution of hot spots, local dense hot regions in plasma pinches is presented. Based on a modified form of the ADRRM 2-D x-ray streak technique reported previously, the new method allows the presence of hot spots to be recorded conclusively. The basics of the technique are described and the limitations of the system discussed. The technique has been applied to study the evolution of hot spots in a plasma focus operating with a mixture of Kr and D2. The results demonstrate that the presence and evolution of the hot spots can be recorded with spatial and temporal resolution in the range of mm and ns, respectively.