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Title: Neutron spectra from beam-target reactions in dense Z-pinches

The energy spectrum of neutrons emitted by a range of deuterium and deuterium-tritium Z-pinch devices is investigated computationally using a hybrid kinetic-MHD model. 3D MHD simulations are used to model the implosion, stagnation, and break-up of dense plasma focus devices at currents of 70‚ÄČkA, 500‚ÄČkA, and 2 MA and also a 15 MA gas puff. Instabilities in the MHD simulations generate large electric and magnetic fields, which accelerate ions during the stagnation and break-up phases. A kinetic model is used to calculate the trajectories of these ions and the neutron spectra produced due to the interaction of these ions with the background plasma. It is found that these beam-target neutron spectra are sensitive to the electric and magnetic fields at stagnation resulting in significant differences in the spectra emitted by each device. Most notably, magnetization of the accelerated ions causes the beam-target spectra to be isotropic for the gas puff simulations. It is also shown that beam-target spectra can have a peak intensity located at a lower energy than the peak intensity of a thermonuclear spectrum. A number of other differences in the shapes of beam-target and thermonuclear spectra are also observed for each device. Finally, significant differences between themore » shapes of beam-target DD and DT neutron spectra, due to differences in the reaction cross-sections, are illustrated.« less
Authors:
;  [1]
  1. Centre for Inertial Fusion Studies, The Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom)
Publication Date:
OSTI Identifier:
22486441
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BEAMS; COMPUTERIZED SIMULATION; CROSS SECTIONS; DEUTERIUM; ENERGY SPECTRA; IMPLOSIONS; IONS; LINEAR Z PINCH DEVICES; MAGNETIC FIELDS; MAGNETIZATION; MAGNETOHYDRODYNAMICS; NEUTRON SPECTRA; PLASMA; PLASMA FOCUS DEVICES; STAGNATION; TRAJECTORIES