Effect of anode shape on correlation of neutron emission with pinch energy for a 2.7kJ Mather-type plasma focus device

Hussain, Shafqat; Ahmad, Shamim; Murtaza, G.; Zakaullah, M.

doi:10.1063/1.3177253

Cited by 9 publications

(3 citation statements)

References 22 publications

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“…The tubular type cathode structure has an increased cathode boundary layer which produced enhanced channel choking effect of the axial phase flow which reduces the overall performance of the plasma focus device. Similar effort was made by Hussain et al [19]. That study was on the effect of anode shape to the neutron emission from 2.7 kJ plasma focus device.…”

Section: Introductionmentioning

confidence: 76%

Parametric Optimisation of Plasma Focus Devices for Neutron Production

et al. 2015

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A large number of experimental investigations have been carried out on plasma focus devices especially at low energy level of several kJ or over 100 kJ. There are few machines operating in the middle energy range of 10-50 kJ, where the neutron yield typically in the order of 10 8 -10 9 per shot. This paper reviews the optimisation process of two different plasma focus devices (12 kJ) by applying the Lee model code. The neutron yield (Y n ) versus pressure (P) curve for several configurations of the two plasma focus provided insight of geometrical optimisation. Measured discharge current is fitted as the first step of modelling to correctly simulate the plasma dynamics. Subsequently the code is used to simulate the neutron yield of the two plasma focus devices based on beam target mechanism. Good agreement between the computed results of neutron yield versus pressure and the measured yield versus pressure is found up to the pressure where highest neutron yield is obtained. Computed highest neutron yield for most of the configuration typically differ by a factor\2.

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Section: Introductionmentioning

confidence: 76%

Parametric Optimisation of Plasma Focus Devices for Neutron Production

et al. 2015

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“…Talukdar et al [14] found that a tapered anode in hydrogen gave the higher hard x-ray photon energy of 125 keV compared to a standard anode. Hussain et al [15] found that a tapered anode increased energy input into the pinch and increased neutron yield by 25% in a 2.5 kJ PF. Recently Schmidt et al [16] described a PF at 1 MJ 2.5 MA developed for neutron imaging radiography (NIR), at operating voltages up to 100 kV.…”

Section: Tapered Anodementioning

confidence: 99%

Thermonuclearizing the plasma focus—converting plasma focus fusion mechanism from beam-gas target to thermonuclear

Lee¹

2022

Plasma Phys. Control. Fusion

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It has been reported that over a range of 3–280 kJ, neutron-optimized deuterium plasma focus machines operate with a near constant speed factor S = 89 ± 8 kA cm−1 per (torr)0.5. This near-constant value of S is consistent with a narrow range of peak axial speeds approximately 10 cm μs−1 and peak radial speeds 20–30 cm μs−1, resulting in focus pinch temperatures less than 0.5 keV and inductively generated high voltages, producing deuteron beams with energies from high tens to hundreds keV. The low pinch temperatures and high beam-deuteron energies result in fusion neutrons predominantly from a beam-target mechanism. A converging taper ending in radius a e, is added to the end of the standard cylindrical anode of radius ‘a’. This taper converts the pinch from one with starting radius ‘a’ to one with a reduced starting radius a e. This increases the value of S and consequently the pinch temperature. This study examines the scaling of the end taper and finds that a taper ending in a radius, which is 1/20 that of the before-taper section increases the pinch temperature by a factor approximately 200, to above 20 keV. This increases the thermonuclear cross-sections by up to 14 orders of magnitude. Numerical experiments using the Lee code confirm that the thermonuclear component of the fusion yield becomes predominant. Such a taper may be considered as a thermonuclear converter.

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“…One of the most important parameters that affects the physical phenomena responsible for ion emissions in a PFD is the "anode cathodes array" assembly and in particular the anode top geometry. Up to now, major efforts have been conducted to investigate neutron emission [5][6][7] and X-ray emission [8][9][10][11][12][13][14] from different anode top geometries in PFDs. However, it seems that studies on ion emission characteristics from different anode top geometries have been rather limited.…”

Section: Introductionmentioning

confidence: 99%

Effects of anode geometry on forward wide-angle neon ion emissions in 3.5 kJ plasma focus device by novel mega-size panorama polycarbonate image detectors

2018

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Forward wide-angle neon ion emissions in a 3.5 kJ plasma focus device (PFD) were studied using 5 different anode top geometries; hollow-end cylinder, solid triangle, solid hemisphere, hollow-end cone and flat-end cone. Position-sensitive mega-size panorama polycarbonate ion image detectors (MS-PCID) developed by dual-cell circular mega-size electrochemical etching (MS-ECE) systems were applied for processesing wide-angle neon ion images on MS-PCIDs exposed on the PFD cylinder top base under a single pinch shot. The images can be simply observed, analyzed and relatively quantified in terms of ion emission angular distributions even by the unaided eyes. By analysis of the forward neon ion emission images, the ion emission yields, ion emission angular distributions, iso-fluence ion contours and solid angles of ion emissions in 4π PFD space were determined. The neon ion emission yields on the PFD cylinder top base are in an increasing order ~2.1×10 9 , ~2.2 ×10 9 , ~2.8×10 9 , ~2.9×10 9 , and ~3.5×10 9 neon ions/shot for the 5 stated anode top geometries respectively. The panorama neon ion images as diagnosed even by the unaided eyes demonstrate the lowest and highest ion yields from the hollow-end cylinder and flat-end cone anode tops respectively. Relative dynamic qualitative neon ion spectrometry was made by the unaided eyes demonstrating relative neon ion energy as they appear. The study also demonstrates the unique power of the MS-PCID/MS-ECE imaging system as an advanced state-of-the-art ion imaging method for wide-angle dynamic parametric studies in PFD space and other ion study applications. K: Nuclear instruments and methods for hot plasma diagnostics; Plasma diagnosticscharged-particle spectroscopy; Heavy-ion detectors; Particle tracking detectors (Solid-state detectors)1Corresponding author.

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Effect of anode shape on correlation of neutron emission with pinch energy for a 2.7kJ Mather-type plasma focus device

Cited by 9 publications

References 22 publications

Parametric Optimisation of Plasma Focus Devices for Neutron Production

Parametric Optimisation of Plasma Focus Devices for Neutron Production

Thermonuclearizing the plasma focus—converting plasma focus fusion mechanism from beam-gas target to thermonuclear

Effects of anode geometry on forward wide-angle neon ion emissions in 3.5 kJ plasma focus device by novel mega-size panorama polycarbonate image detectors

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