Electrical behavior of exploding copper wire in ambient air

This work experimentally investigates the electrical behavior of an exploding wire when the initial energy of the system varies from 28 to 709 J. This experiment uses 50-um-diameter, 33-mm-long copper wires. The wire is surrounded by air at normal atmospheric pressure and temperature. The experiment monitored the current derivative, voltage between wire ends, total visible radiation emitted, and the shadow image of the wire to study how the electrical parameters vary as a function of initial energy. The results indicate a change in the initial discharge mechanism.Fil: Barbaglia, Mario Oscar. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Física Arroyo Seco; ArgentinaFil: Rodriguez Prieto, Gonzalo. Universidad de Castilla-La Mancha; Españ

A model of hard X-rays emission from free expanding Plasma-Focus discharges

A planar-piston model of the hard x-ray production in Plasma-Focus devices is presented. The model applies Von Karman approximations to represent the inner structure of the pinch. The hard x-ray emission is calculated assuming Bremsstrahlung from the collision on the anode base of an electron current running away from the pinch.. The model was applied to analyse the experimental data of a small Plasma Focus without surrounding cathode, finding good agreement.Fil: Fogliatto, Ezequiel Oscar. Comisión Nacional de Energía Atómica. Gerencia del Area de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Gonzalez, Jose Hector. Comisión Nacional de Energía Atómica. Gerencia del Area de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil; ArgentinaFil: Barbaglia, Mario Oscar. Comision Nacional de Energi­a Atomica. Centro Atomico Bariloche; ArgentinaFil: Clausse, Alejandro. Comision Nacional de Energi­a Atomica. Centro Atomico Bariloche; Argentin

A study of the effects of the cathode configuration on the plasma kinetics and neutron emission of plasma-focus discharges in deuterium

The differences in performance of a 1.9 kJ plasma-focus device PACO assembled with three different cathode configurations are experimentally qualified. In particular, the current sheath kinetics and the neutron yield operating with deuterium gas are systematically studied for the whole range of neutron-producing pressures, and the measurements are analyzed searching for relations between relevant physical magnitudes. The pinching time was found correlated with the dimensionless driver parameter, and this feature was found statistically independent of the cathode. The variation of the inductance jump associated with the radial collapse stage is used to estimate the effective pinch length, (7.3 ± 1.6) mm, and radius, (3.6 ± 2.1 ) mm. The maximum production in a single shot was registered for the smallest cathode radius, 41 mm, whereas the intermediate cathode radius, 45 mm, scored better in average. In all configurations, the neutrons per deuteron pair correlates fairly well with an estimation of the effective equilibrium temperature of the pinch, which suggests a prevalence of thermonuclear neutrons measured perpendicularly to the focus axis.Fil: Barbaglia, Mario Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Giovachini, Ricardo Hernán. Universidad Nacional del Centro de la Provincia de Buenos Aires; ArgentinaFil: Milanese, Maria Magdalena. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Clausse, Alejandro. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin

Temporal shock wave analysis produced by copper exploding wires in air at atmospheric pressure

In this work, experimental results concerning the temporal evolution of the shock wave radii generated by an exploding copper wire of fixed length are presented. The variables of the experience were the diameter dimension—from 50 to 500 μm—and the initial capacitor voltage—from 5 to 25 kV. The diagnostic device was a streak shadow image system synchronized with the experiment. The result is a parametric collection of data showing the shock wave position across the time depicting the different stages of the experience.Fil: Barbaglia, Mario Oscar. Universidad Nacional del Centro de la Pcia.de Bs.as.. Centro de Investigaciones En Física E Ingeniería del Centro de la Provincia de Buenos Aires. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones En Física E Ingeniería del Centro de la Provincia de Buenos Aires. Provincia de Buenos Aires. Gobernación. Comision de Invest.científicas. Centro de Investigaciones En Física E Ingeniería del Centro de la Provincia D; ArgentinaFil: Rodriguez Prieto, G.. Universidad de Castilla-La Mancha; Españ

Dense plasma focus: different cathode geometries and their influence on the hard x-ray production

Using the plasma-focus device called PACO (Plasma Auto COnfinado), three types of cathodes were experimentally investigated to evaluate their influence on the hard x-ray production. Two barred cathodes with diameters of 82 mm and 90 mm and one cathode without any specific structure (i.e. the current sheet flowed freely on the radial axis) were tested for this work. In every experiment, the capacitor bank was charged to 31 kV. The gas used was deuterium in the pressure range of 0.5 mbar and 3.0 mbar. The production of neutrons and hard x-ray simultaneously was not detected outside this range. Using the cathode with a diameter of 82 mm the hard x-ray production was maximized.Fil: Barbaglia, Mario Oscar. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Mecanica. Grupo de Ingeniería Asistida Por Computador; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Giovachini, Ricardo Hernán. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Física Arroyo Seco; ArgentinaFil: Milanese, Maria Magdalena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Electrical Behavior of an Ultralow-Energy Plasma-Focus Device

Measurements of electrical signals in discharges performed in a miniature plasma-focus device (5 nF capacitor bank, central electrode diameter and effective free length 2.0 and 0.5 mm, respectively, no outer electrode) are reported. A lumped  model is built that gives good agreement between the model and the recorded signals. The main conclusions are as follows: the voltage at which the chamber disk capacitor is charged is limited by the gas filling pressure inside the chamber and not just by the voltage in the capacitor energy source, and the behavior of the discharge current within the vacuum chamber depends on the whole system and not only on the last portion of the circuit, even for longer transmission line lengths.Fil: Barbaglia, Mario Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires; ArgentinaFil: Bruzzone, Horacio Abel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Acuña, Hugo Néstor. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Soto, Leopoldo. Comision Chilena de Energía Nuclear; Chile. Center for Research and Applications in Plasma Physics and Pulsed Power P4; ChileFil: Clausse, Alejandro. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Images of a plasma focus current sheath with a continuous cylindrical outer electrode

Images of the roll-off, radial compression, final pinch, and after pinch stages of the current sheath (CS) of the dense plasma focus PACO (plasma autoconfinado) whose outer electrode is a brass cylindrical shell are shown. The different stages of the current sheath were measured with an image converter camera, 5-ns exposure time. The images of the CS evolution look similar to those previously obtained with an array of bars as cathode, as well as neutron yields and working pressures.Fil: Milanese, Maria Magdalena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigaciones En Física E Ingeniería del Centro de la Provincia de Buenos Aires; ArgentinaFil: Cortázar, Osvaldo Daniel. Universidad de Castilla-la Mancha; EspañaFil: Barbaglia, Mario Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigaciones En Física E Ingeniería del Centro de la Provincia de Buenos Aires; ArgentinaFil: Moroso, Roberto Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigaciones En Física E Ingeniería del Centro de la Provincia de Buenos Aires; Argentin

Experimental study of the hard x-ray emissions in a plasma focus of hundreds of Joules

An experimental study on hard x-ray production in a small plasma focus device operating in a few hundreds of Joule range is presented. A threshold in the voltage drop on the pinch was observed for x-ray emission. A comparison with Dreicer theory for electrons runaway in plasmas yields significant agreement. The study was performed at a constant pressure (1.8 mbar) of deuterium with three different anode lengths.Fil: Barbaglia, Mario Oscar. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bruzzone, Horacio Abel. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Acuña, Hugo Néstor. Universidad Nacional de Mar del Plata; ArgentinaFil: Soto, L.. Comision Chilena de Energía Nuclear; ChileFil: Clausse, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentin

Assessment of relevant pinch magnitudes of plasma focus devices based on non-uniform internal distributions of density and temperature

A novel model of the dense z-pinch of a plasma focus (PF) discharge is presented, assuming Gaussian radial distributions of density and temperature inside the pinch. The model is used to assess the temperature, size and lifetime of the focus conflating with available experimental data gathered from discharges in Deuterium performed in the PF PACO with three cathode configurations. The resulting estimations were mean pinch temperatures between 1 and 12 keV, and pinch durations between 10 and 120 ns, each magnitude decreasing and increasing with the filling pressure, respectively. Moreover, the relation found between the mean pinch radius and temperature, ⟨ r p ⟩ and ⟨ T p ⟩ , is consistent with an adiabatic compression given by ⟨ r p ⟩ ⟨ T p ⟩ 3 / 4 ≅ 1.2 − 1.6 mm keV3/4. The estimated width of the Gaussian profile is in agreement with spectroscopic images obtained in another small device.Fil: Giovachini, Ricardo Hernán. Universidad Nacional del Centro de la Provincia de Buenos Aires; ArgentinaFil: Barbaglia, Mario Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Abraham Ekeroth, R. M.. Universidad Nacional del Centro de la Provincia de Buenos Aires; ArgentinaFil: Clausse, Alejandro. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin