Miniature plasma focus device: A versatile multiple radiation source

It is a well known fact that the typical plasma parameters, such as density and temperature of the pinched plasma, in a very large energy plasma focus device (such as mega-joule range PF1000 facility at ICDMP, Warsaw) and low energy plasma focus device (such 3 kJ UNU/ICTP or NX2 devices at NIE/NTU, Singapore) are very similar. Hence, the radiation and particle spectrum from a sub-kJ energy miniature plasma focus are very similar to one obtained from mega-joule energy large plasma focus device; though the radiation/particle yields which typical scale as certain power of discharge current or energy will have different magnitudes. The low energy sub-kJ range miniature plasma focus devices are technologically as well as physically easier to assemble and operate. Due to low electrical power and thermal load requirements, low energy miniature plasma focus devices can be made to operate in high repetition rate regime making them efficient table top device with easy of portability. The research and development of compact fast repetitive miniature plasma focus devices, with stored energy from few tens to few hundred joules, is therefore becoming increasingly important because of their potential applications in variety of field such as high repetition EUV or soft X-ray source for microlithography, hard X-ray source for non destructive testing, portable neutron source for explosive and contraband material detection and high repetition rate high energy density plasma based nanopartilces and nanostructured thin film synthesis. In this invited talk, the conceptualization, development and applications of three versions of FMPF (Fast Miniature Plasma Focus) devices, along with key technical and physical issues and challenges encountered, will be discussed. The progress summary from low neutron yield of about 1×104 neutrons/shot from first version FMPF-1 to the record time averaged neutron yield of 1×107 neutrons/second from upgraded 10 Hz repetitive FMPF-3 device will the reported. On the application side, the use of miniature plasma focus devices for hard x-ray imaging of various objects, deposition of FeCo and diamond like carbon thin films will be presented. (author)