Using a 4.7 kJ Plasma Focus for introspective imaging of metallic objects and for neutronic detection of water

Abstract

A compact Plasma Focus operated in Deuterium has been used as a pulsed radiation source for two different applications: x-ray introspective imaging of metallic objects and water detection by elastic neutron scattering. The samples for radiographic imaging were located outside the PF chamber, about 1 m away from the chamber wall. High-sensitivity, fast-response commercial radiographic film was used as x-ray detector. Experimental images are presented demonstrating a very high penetration power of the x-ray beam. Among many other applications, the presented technique is specially suited for ultrafast introspective visualization of pieces manufactured on metal. Regarding to the second application, a method to detect the presence of water in the neighborhood of a compact Plasma Focus is presented. The measuring system is composed by two silver activation detectors operated simultaneously on every shot. The first detector is used to register the PF neutron yield; whereas the other one is used to detect neutrons scattered by the blanket. Our results indicate that the constructed system is able to detect water contents of few percents in volume. Because of the scattered nature of the prospection neutrons, the method admits side-on substance interrogation, i.e., the interrogated substance does not need to be placed in the PF-to-detector line of sight.