Evidence of non-thermal processes in a 1-MJ plasma focus device by analysing the neutron spectra

Milanese, M.; Pouzo, J.

doi:10.1088/0029-5515/18/4/010

Cited by 28 publications

(26 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…27 We could give two neutron pulses, 9,10,45,46 the efficient production of 100 keV deuterons 10,52 and broad radial spectra 7,8,10,53,54 as examples. The experiment on the GIT-12, which provides two different current rise-times somewhere between fast Z-pinches and plasma foci, confirmed these observation.…”

Section: E Comparison With Plasma Focimentioning

confidence: 99%

Deuterium gas puff Z-pinch at currents of 2 to 3 mega-ampere

et al. 2012

View full text Add to dashboard Cite

Deuterium gas-puff experiments have been carried out on the GIT-12 generator at the Institute of High Current Electronics in Tomsk. The emphasis was put on the study of plasma dynamics and neutron production in double shell gas puffs. A linear mass density of deuterium (D2) varied between 50 and 85 μg/cm. Somewhat problematic was a spread of the D2 gas at a large diameter in the central anode–cathode region. The generator operated in two regimes, with and without a plasma opening switch (POS). When the POS was used, a current reached a peak of 2.7 MA with a 200 ns rise time. Without the POS, a current rise time approached 1500 ns. The influence of different current rise times on neutron production was researched. Obtained results were important for comparison of fast deuterium Z-pinches with plasma foci. Average DD neutron yields with and without the POS were about 1011. The neutron yield seems to be dependent on a peak voltage at the Z-pinch load. In all shots, the neutron emission started during stagnation. At the beginning of the neutron production, the neutron emission correlated with soft x-rays and a significant fraction of neutrons could be explained by the thermonuclear mechanism. Nevertheless, a peak of the neutron emission occurred 40 ns after a soft x-ray peak. At this very moment, hard x-rays above 1 MeV were detected and a rapid expansion with a velocity of 3×105 m/s was observed. In the case of the POS, 1 MeV widths of radial neutron spectra implied that there are deuterons with the energy above 200 keV moving in the radial direction. On the basis of D2 gas puff experiments in the 0.3–17 MA region, the neutron yield dependence on a current as Y∝I3.0±0.2 was proposed.

show abstract

Section: E Comparison With Plasma Focimentioning

confidence: 99%

Deuterium gas puff Z-pinch at currents of 2 to 3 mega-ampere

et al. 2012

View full text Add to dashboard Cite

show abstract

“…According to the authors 10 , such peaks were consistent with "a 100 keV deuteron loop in the plane determined by the gun axis and the observational direction". Sometimes, these peaks were not sufficiently separated resulting in a single broad peak 10 with a width in the range of 0.5-0.7 MeV, which have been observed on other installations as well 11,12 .…”

Section: Introductionmentioning

confidence: 58%

“…• Neutron ToF spectrum on the Frascati 1 MJ plasma focus at 90° to the axis with a 128 m flight path 10 showed 3 peaks: one central peak centered on the 2.45 MeV Q-value of the D-D fusion reaction with a Full Width at Half Maximum (FWHM) of 0.2-0.5 MeV and two distinct side peaks. According to the authors 10 , such peaks were consistent with "a 100 keV deuteron loop in the plane determined by the gun axis and the observational direction".…”

Section: Introductionmentioning

confidence: 99%

Dense Plasma Focus: A question in search of answers, a technology in search of applications

Auluck

2014

Int. J. Mod. Phys. Conf. Ser.

View full text Add to dashboard Cite

Diagnostic information accumulated over four decades of research suggests a directionality of toroidal motion for energetic ions responsible for fusion neutron production in the Dense Plasma Focus (DPF) and existence of an axial component of magnetic field even under conditions of azimuthal symmetry. This is at variance with the traditional view of Dense Plasma Focus as a purely irrotational compressive flow. The difficulty in understanding the experimental situation from a theoretical standpoint arises from polarity of the observed solenoidal state: three independent experiments confirm existence of a fixed polarity of the axial magnetic field or related azimuthal current. Since the equations governing plasma dynamics do not have a built-in direction, the fixed polarity must be related with initial conditions: the plasma dynamics must interact with an external physical vector in order to generate a solenoidal state of fixed polarity. Only four such external physical vectors can be identified: the earth's magnetic field, earth's angular momentum, direction of current flow and the direction of the plasma accelerator. How interaction of plasma dynamics with these fields can generate observed solenoidal state is a question still in search of answers; this paper outlines one possible answer. The importance of this question goes beyond scientific curiosity into technological uses of the energetic ions and the high-power-density plasma environment. However, commercial utilization of such technologies faces reliability concerns, which can be met only by first-principles integrated design of globallyoptimized industrial-quality DPF hardware. Issues involved in the emergence of the Dense Plasma Focus as a technology platform for commercial applications in the not-too-distant future are discussed.

show abstract

“…The FWHM values of experimentally observed neutron spectra quite well agree with the results of this study. Indeed, experi ments in most cases give the FWHM values about 400-700 keV [8][9][10][11][12][13][14][15][16][17][18][19], which fall within the theoreti cally possible interval for plasma with an ion energy distribution possessing a high energy tail decaying as f~ 1/ with k = 2-3.…”

Section: Discussionmentioning

confidence: 99%

On the spectrum of Z-pinch plasma neutrons

Vikhrev

Mironenko-Marenkov

2012

Plasma Phys. Rep.

View full text Add to dashboard Cite

Generation of neutrons from Z pinch discharges in a deuterated gas medium has been studied. It is shown that a power law energy dependence of the number of high energy deuterons in Z pinch plasma explains the observed broadening of the neutron spectrum in these systems. It is established that, at an average ion energy below 3 keV in Z pinch plasma, neutrons are mostly generated due to the interaction of high energy (~100 keV) deuterons with the main plasma components.

show abstract

Evidence of non-thermal processes in a 1-MJ plasma focus device by analysing the neutron spectra

Cited by 28 publications

References 12 publications

Deuterium gas puff Z-pinch at currents of 2 to 3 mega-ampere

Deuterium gas puff Z-pinch at currents of 2 to 3 mega-ampere

Dense Plasma Focus: A question in search of answers, a technology in search of applications

On the spectrum of Z-pinch plasma neutrons

Contact Info

Product

Resources

About