Transition from Beam-Target to Thermonuclear Fusion in High-Current Deuterium<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Z</mml:mi></mml:math>-Pinch Simulations

Offermann, Dustin; Welch, D. R.; Rose, D. V.; Thoma, C.; Clark, Robert E.; Mostrom, C. B.; Schmidt, Andréa; Link, A.

doi:10.1103/physrevlett.116.195001

Cited by 18 publications

(2 citation statements)

References 22 publications

(33 reference statements)

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“…Recently, state-of-the-art numerical codes have opened up new possibilities to solve this very old problem in plasma physics. The dynamics of deuterium gas-puff z-pinches and DPFs was simulated by the fully kinetic particle-in-cell LSP code [9][10][11][12] as well as by 3D-MHD GORGON code [13]. Most of these simulations attempted to explain a high DD neutron yield of 4×10 13 in a deuterium gas-puff on the Z machine [14,15].…”

Section: Introductionmentioning

confidence: 99%

Ion acceleration mechanism in mega-ampere gas-puff z-pinches

et al. 2018

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Acceleration of high energy ions was observed in z-pinches and dense plasma foci as early as the 1950s. Even though many theories have been suggested, the ion acceleration mechanism remains a source of controversy. Recently, the experiments on the GIT-12 generator demonstrated acceleration of ions up to 30 MeV from a deuterium gas-puff z-pinch. High deuteron energies enable us to obtain unique information about spatial, spectral and temporal properties of accelerated ions. In particular, the offaxis ion emission from concentric circles of a ∼1 cm diameter and the radial lines in an ion beam profile are germane for the discussion of acceleration mechanisms. The acceleration of 30 MeV deuterons can be explained by the fast increase of an impedance with a sub-nanosecond e-folding time. The high (>10 Ω) impedance is attributed to a space-charge limited flow after the effective ejection of plasmas from m=0 constrictions. Detailed knowledge of the ion acceleration mechanism is used with a neutron-producing catcher to increase neutron yields above 10 13 at a currentof2.7 MA.

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Section: Introductionmentioning

confidence: 99%

Ion acceleration mechanism in mega-ampere gas-puff z-pinches

et al. 2018

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“…Plasmas 24, 012702 (2017) been shown to increase the beam-target fusion yields. 3,40,50,53 Both conclusions are supported by measurements taken on the 1.1-MJ DPF showing more consistent pulse widths but lower yields with a round-top anode. Specifically, at 35 kV and 5.5-Torr DD gas pressure, the total neutron yield for the flat-top anode with reentrant cathode is 2:0560:81 Â 10 11 , while the yield from the hemispherical anode is approximately half this value.…”

Section: -7mentioning

confidence: 63%

Development of the dense plasma focus for short-pulse applications

et al. 2017

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The dense plasma focus (DPF) has long been considered a compact source for pulsed neutrons and has traditionally been optimized for the total neutron yield. In this paper, we describe the efforts to optimize the DPF for short-pulse applications by introducing a reentrant cathode at the end of the coaxial plasma gun. The resulting neutron pulse widths are reduced by an average of 21±9% from the traditional long-drift DPF design. Pulse widths and yields achieved from deuterium-tritium fusion at 2 MA are 61.8±30.7 ns FWHM and 1.84±0.49×1012 neutrons per shot. Simulations were conducted concurrently to elucidate the DPF operation and confirm the role of the reentrant cathode. A hybrid fluid-kinetic particle-in-cell modeling capability demonstrates correct sheath velocities, plasma instabilities, and fusion yield rates. Consistent with previous findings that the DPF is dominated by beam-target fusion from superthermal ions, we estimate that the thermonuclear contribution is at the 1% level.

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