New trends and future perspectives on plasma focus research

Abstract

This paper includes a brief overview of the contributions and results of several groups working in plasma focus (PF) devices around the world in the last few years. In section 2 a summary of the most important results of the dense transient plasma research programme of the Comisión Chilena de Energía Nuclear is presented. An approach to an integrated vision of the present PF research status is presented in the next section. Some parameters that remain practically constant in PF devices that operate in a wide range of energies from 1 MJ to tens of joules are discussed. These parameters ('plasma energy density parameter' and 'drive parameter') are used as a design tool to achieve an ultra-miniature pinch focus device operating at energies less than 1 J. Preliminary results of such an ultra-miniature device are presented. Applications to non-destructive tests, detection of substances, pulsed radiation in biology and material sciences are also briefly discussed in this paper.

Electromagnetic Burst Measurement System Based on Low Cost UHF Dipole Antenna

“…Thus, we need to determine the antenna factor (AF) at these low frequencies to properly estimate the electric field of the EMN. The antenna Energies 2017, 10, 1415 4 of 16 was selected at higher frequencies for two main reasons: (1) to produce the smallest perturbation of the electric field of the burst, which is achieved by a small antenna (optimized for high frequencies); and (2) to avoid damage in the equipment acting as receiver, in our case an oscilloscope. To be able to receive EMN signals far from the resonance frequency of the antenna guaranties that the voltage getting into the oscilloscope is at safe levels even for intense EMN bursts.…”

“…The international plasma community has demonstrated a renewed interest in dense plasma focus devices (DPFs), due to their many capabilities that make them versatile apparatus in research and applications [1]. These self-scale plasma devices can generate neutron pulses [2][3][4], work as a pulsed X-ray source [5], produce plasma shocks [6], supersonic plasma jets [7], plasma filamentation [8], scaled astrophysical experiments [7] and they can also be used as a source to test new materials for the first wall of future fusion devices [9].…”

Plasma Current Sheath Motion in Coaxial Plasma Discharge

“…Also a drive parameter   p I a  , where I p is the peak discharge current, a is the inner electrode radius and ρ is the ambient gas density, has been derived previously to a plasma focus devices of different types [10][11][12][13] This parameter determines the speed of the PCS in both axial and radial phases and it has a constant value for Mather type of different aspect ratios, gas pressures and discharge current [11]. Also some authors confirmed that the drive parameter has a remarkably constant value of PF devices with a range of energies from a few KJ to hundreds of KJ [14].…”

Potentiality of a table top plasma focus as X-ray source: Radiographic applications

“…The duration of these pulses is of the order of tens to hundreds of nanoseconds. Using deuterium gas, PF devices produce fusion D-D reactions, generating fastneutron pulses (∼2.5 MeV) [3]. From the beginning in the research in plasma focus, a growing interest has been placed in the potential use of its powerful pulsed radiation, as alternative source for application both in medicine and industry.…”

“…However, this kind of sources has the technical disadvantage of the repetition regime, unlike to the performance that could have a plasma focus device, especially those of low energy. Radiographic applications using dense transient PF devices operating at some kJ or greater energy have been obtained in several laboratories in both biological radiography [5,6] and introspective radiography of non-biological objects [7,8] [3,[9][10][11][12][13][14][15][16]. Another advantage that favors the development of small plasma focus devices is the scaling observed in the dimensions of the pinch [17].…”