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The effect of ferroelectric lead germanate Pb5Ge3O11 (PGO) thick film in the alumina insulator sleeve of the 400 Joule Mather-type plasma focus device, PF-400J is studied. The breakdown phase along the insulator is fundamental for the formation of a homogeneous and symmetric current sheath, that is essential for a good plasma pinching, high neutron yield and X-ray emissions. For over several hundreds of electrical discharges, the films show good mechanical and electric performance. From the beginning the operating system is highly reproducible, shot to shot, with a clear definition of the plasma pinch on the axis of discharge. The grade of influence of the electron emission from the ferroelectric is experimentally studied. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Preliminary results in a gas embedded Z-pinch driven by the SPEED2 generators are presented. A 0-D model for a quasi static z-pinch with variable line density has been applied to determined the initial conditions to produce a gas embedded z-pinch to be driven by SPEED2 generator. Initial conditions to produce a gas embedded z-pinch with enhanced stability by means resistive effects and by finite Larmor radius effects were obtained. Using these results the electrodes were designed and constructed. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Recently, the pulse power generator SPEED 2, a medium energy and large current device (187kJ, 4MA, 300kV, 400ns, dI/dt ∼ 10[sup 13] A/s), has been transfered from the Düsseldorf University to the Plasma Physics Group of the Comisión Chilena de Energía Nuclear (CCHEN). The SPEED 2 arrived at CCHEN in May 2001 and was in operation in January 2002, being the most powerful device for dense transient plasma in the Southern Hemisphere. Experiments in different Z-pinch configurations using the SPEED 2 generator will be carried out at CCHEN in the future. Possible objectives using the SPEED 2 devices are discussed in this work: a) Neutron flux characteristics from plasma focus discharges operating in D[sub 2] (with temporal and spatial resolution) correlated to discharge parameters, plasma dynamics and instabilities. Particular investigation of the effect of insulator surface preparation and conditioning on pinch behavior and neutron yield, b) High brightness and soft X-ray radiation from transient electrical discharges, especially in wire arrays, and c) Magnetic confinement in a quasistatic z-pinch at mega ampere peak current. Plasma dynamics and stability in an original quasi-static z-pinch configuration (a gas embedded compressional Z-pinch) and in a combination scheme that use gas puff and plasma focus will be studied at high current using the SPEED 2 generator. Results about SPEED 2 performance, obtained in Chile, are presented. [ABSTRACT FROM AUTHOR]

Experiments in a small and fast capillary discharge have been performed. Submillimeter capillaries with centimeters length were used. The discharge is operated in argon, with a cathode pressure of 100-500 mtorr. The system works with differential vacuum, thus, the anode pressure is around five times less than the cathode pressure. For an applied voltage of 10kV, a peak current of 4 to 5 kA with a rise time of 2 to 5 ns is obtained (∼10[sup 12] A/s). In addition to usual electrical diagnostics, time-space resolution pinhole images (multipinhole camera with a microchannel plate, four frames, one frame every 4 ns) and time resolved spectra in the region of 20 to 80 nm were performed. Dynamics of plasma compression can be studied from time resolved pinhole images. Detected spectra show that plasma consists of argon ions with ionization potential from ArVII to ArX. [ABSTRACT FROM AUTHOR]