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Results of the internet-based workshop on plasma focus numerical experiments
Citation
Lee, S. (2008, July). Results of the internet-based workshop on plasma focus numerical experiments. Paper presented at the International Workshop On Plasma Computations & Applications (IWPCA 2008), Kuala Lumpur, Malaysia.
Author
Lee, Sing
Abstract
The Institute of Plasma Focus Studies was founded with the aim of using the Lee model code to assist training of plasma focus scientists in the same way that the UNU/ICTP PFF was used successfully to train a generation of plasma focus researchers. The inaugural activity of the IPFS was an internet-based Workshop on Plasma Focus Numerical Experiments. Over 4 weeks, 30 participants were guided to configure the RADPFV5.13.9b to operate a range of machines from the tiny PF400 to the 1 MJ PF1000. Important exercises included fitting a plasma focus so that the computed current waveform agrees, in axial and radial features, with the measured waveform, thus obtaining the model parameters of that particular machine. Computed properties were tabulated side-by-side for a small and a big machine to show similar properties and scalable properties. The evolution of current profiles with pressure was traced for a neutron yielding focus as well as for a neon soft x-ray yielding focus. 17 participants from 9 countries successfully submitted all exercises. A surprising development is also reported. This concerns an additional exercise given to participants to be attempted in future. Numerical experiments in connection with this exercise show that contrary to what Nukulin and Polukhin surmised, there is neither current nor neutron saturation attributable to purely electrodynamic effects for plasma focus machines up to 25 MJ. The numerical experiments show that early peaking of the current profile for megajoule banks invalidates the crux of the N & P argument. The numerical experiments also find the conditions at which a 3 MJ plasma focus may yield 1013 D-D neutrons, a landmark target for materials testing in connection with first wall materials in fusion reactors.
Date Issued
July 2008
Description
This paper was presented at the International Workshop On Plasma Computations & Applications (IWPCA 2008), held in Kuala Lumpur, Malaysia from 14 - 15 Jul 2008