LABORATORI NAZIONALI DI LEGNARO
The Plasma Focus device is a pulsed electrical discharge in different gases which was discovered independently by Mather (1961) and Filippov (1954). Since then PF devices have been built with energies ranging from a few joules to a few mega-joules with a consequent variation in the physical size. The PF has a very complex behavior and exhibits a rich variety of plasma phenomena. The formation of plasma and improvement include 3 main phases: i) the breakdown phase, ii) the axial acceleration phase and iii) the radial collapse phase. In the final phase, a hot (~1keV) and dense (~1019 cm-3) plasma will be formed. In the unstable sub-phase, micro-instabilities occur and disrupt the pinch plasma column which is a rich source of radiation. It emits an intense of electromagnetic radiation such as soft x-ray source for next-generation microelectronics lithography and surface micromachining, high energy particle beams (electron and ion) for materials modification, and a burst of nuclear fusion products (when operated in deuterium) e.g. pulsed neutron source for medical and security inspection applications. When the pinch discharge channel is imploded, a several kind of MHD and kinetic instabilities will occur, most importantly, the Rayleigh-Taylor instabilities (m = 0 and m = 1).