Calibration methodology for proportional counters applied to yield measurements of a neutron burst

This paper is a sequel to the 1998 review paper “Scientific status of the Dense Plasma Focus” with 16 authors belonging to 16 nations, whose initiative led to the establishment of the International Center for Dense Magnetized Plasmas (ICDMP) in the year 2000. Its focus is on understanding the principal defining characteristic features of the plasma focus in the light of the developments that have taken place in the last 20 years, in terms of new facilities, diagnostics, models, and insights. Although it is too soon to proclaim with certainty what the plasma focus phenomenon is, the results available to date conclusively indicate what it is demonstrably not. The review looks at the experimental data, cross-correlated across multiple diagnostics and multiple devices, to delineate the contours of an emerging narrative that is fascinatingly different from the standard narrative, which has guided the consensus in the plasma focus community for several decades, without invalidating it. It raises a question mark over the Fundamental Premise of Controlled Fusion Research, namely, that any fusion reaction having the character of a beam-target process must necessarily be more inefficient than a thermonuclear process with a confined thermal plasma at a suitably high temperature. Open questions that need attention of researchers are highlighted. A future course of action is suggested that individual plasma focus laboratories could adopt in order to positively influence the future growth of research in this field, to the general benefit of not only the controlled fusion research community but also the world at large.

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“…Neutron yields as low as 10 2 neutrons per pulse were measured. Details of the system and calibration were published in references [231,235].…”

Section: Low Neutron Yield Detectionmentioning

confidence: 99%

Update on the Scientific Status of the Plasma Focus

Auluck

Kubeš

Paduch

et al. 2021

Plasma

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“…The neutron yield was measured with two moderated 3 He-filled proportional counters located side-on and end-on to the electrode configuration 19 cm from the pinch focus. The uncertainty for single shot measurements is estimated from a statistical model of the response of the proportional counter [43][44][45]. The uncertainty for a measured neutron yield of 5000 n/burst is less than 20% and 50% for 900 n/burst.…”

Section: Methodsmentioning

confidence: 99%

Effects of gas chamber geometry and gas flow on the neutron production in a fast plasma focus neutron source

Tarifeño-Saldivia

Soto

2014

Plasma Phys. Control. Fusion

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“…For the detection and evaluation of the neutron pulse, two moderated 3 He-filled proportional counters ( 3 He tubes) were used. Both detectors were calibrated for different operating distances according to the procedures described in [34,35]. The detectors were positioned symmetrically at 2.1 m from the discharge axis, in the plane containing the neutron source.…”

Section: X-ray and Neutron Detection Diagnosticsmentioning

confidence: 99%

New evidence about the nature of plasma filaments in plasma accelerators of type plasma-focus

Pavez¹,

Zorondo²,

Pedreros³

et al. 2022

Plasma Phys. Control. Fusion

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In this work, new evidence and information about both the origin and evolution of filamentary structures observed in the current sheath of a small plasma focus discharge are reported. The experiments were carried out in a small generator of low energy (multipurpose generator MPG), at the plasma focus configuration, under different operation conditions. These include different anode and insulator geometries, without return bars and a high-performance regime of the generator at high pressures (> 10 mbar). The evolution of the plasma structures is characterized by mean of refractive optical techniques. The electrical behavior of the discharge, as well as its performance, are monitored with conventional electrical diagnostics and neutron and X-ray detectors, respectively. Plasma filaments of the same species are present in all tested configurations, however, in those with a large effective anode length (and smaller anode radius), the plasma region containing the filaments moves away from the anode surface and it is confined in a region of the plasma sheath, such as a toroidal plasma belt, without reaching the anode top nor participating in the radial compression phase. According to images of the plasma sheath in its early phase, the filaments originate and evolve from a precursor annular plasma formed in the lower part of the anode next to the insulator, in the process of electrical breakdown. The local character that these dense-filamentary structures acquire in the evolution of the plasma sheath would discard the current-filament hypothesis. On the other hand, in experiments in deuterium gas with a large effective anode length and without filaments in the radial compression phase, a high performance at the neutron and X-rays production were obtained.

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Calibration methodology for proportional counters applied to yield measurements of a neutron burst

Cited by 8 publications

References 25 publications

Update on the Scientific Status of the Plasma Focus

Update on the Scientific Status of the Plasma Focus

Effects of gas chamber geometry and gas flow on the neutron production in a fast plasma focus neutron source

New evidence about the nature of plasma filaments in plasma accelerators of type plasma-focus

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