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.
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 31KV. 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.
A novel model of the dense z-pinch of a Plasma Focus 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 recorded from discharges in deuterium gas. The model was applied to analyze experimental data gathered from discharges in Deuterium performed in the Plasma Focus 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, 〈rp 〉 and 〈Tp〉 , is consistent with an adiabatic compression given by 〈rp〉〈Tp〉^(3/4) ≅1.2-1.6 mm keV^3/4. The estimated width of the Gaussian profile is consistent with spectroscopic images obtained in small devices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.