Plasma focus ion beam fluence and flux—For various gases

Abstract

A recent paper derived benchmarks for deuteron beam fluence and flux in a plasma focus (PF) [S. Lee and S. H. Saw, Phys. Plasmas 19, 112703 (2012)]. In the present work we start from first principles, derive the flux equation of the ion beam of any gas; link to the Lee Model code and hence compute the ion beam properties of the PF. The results show that, for a given PF, the fluence, flux, ion number and ion current decrease from the lightest to the heaviest gas except for trend-breaking higher values for Ar fluence and flux. The energy fluence, energy flux, power flow, and damage factors are relatively constant from H2 to N2 but increase for Ne, Ar, Kr and Xe due to radiative cooling and collapse effects. This paper provides much needed benchmark reference values and scaling trends for ion beams of a PF operated in any gas.

Detection of energetic particles from plasma focus using Faraday cup and SSNTD (LR-115A)

“…The velocity, energy and density of helium ions are estimated using TOF technique (Gerdin et al, 1981;Wong et al, 2002). The ion velocity is estimated by taking the ratio of the distance to the flight time of ions from source to detector (Lee and Saw, 2013). The variation of ion flux with filling helium gas pressure is shown in Figure 4.…”

Comparison of Measured Soft X-Ray Yield Versus Pressure for NX1 and NX2 Plasma Focus Devices Against Computed Values Using Lee Model Code

“…Lee et al [61][62][63] have published various works with laboratory measurements from the NX2, including information and a typical current waveform on soft X-ray yield at a typical pressure of 4 mbar (i.e. 3 torr) with 5 cm anode operated at 11.5 kV and also with pressure 2.6 torr with 5 cm anode operated with 11 kV [35].…”

“…The inclusion of the neutron yield, Y n , using beam target mechanism [44,[54][55][56] is one the great step in the development, incorporated in the versions [54,55] of the code (later than RADPF5.13), resulting in realistic Y n scaling with I pinch [44,47,48]. The code has been used to develop scaling laws for soft X-rays [36,[57][58][59][60] and bench-mark numbers and scaling trends for ion beam flux, ion beam fluence, beam ion number, ion beam current, power flow density, and damage factor for all gases [61,62]. Application of ion beam calculations to production of short-lived radioisotopes were made by Akel et al [63].…”

Parametric Optimisation of Plasma Focus Devices for Neutron Production

“…Four model parameters; axial and radial mass factors, axial and radial current factors have been obtained by fitting the computed current waveform against measured current waveform. In the past, extensive numerical experiments using Lee model code has been applied for the modelling of soft X-ray scaling law [28], neutron scaling law [29] and in most recent years for the modelling of ion beam properties [30][31][32]. In this paper, we gain further insight related to the neutron production mechanism for the 12 kJ plasma focus device.…”